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The effects of low-dose fluvastatin and valsartan combination on arterial function: A randomized clinical trial
European Journal of Internal Medicine 23 (2012) 261–266
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European Journal of Internal Medicine journal homepage: www.elsevier.com/locate/ejim
Original article
The effects of low-dose fluvastatin and valsartan combination on arterial function: A randomized clinical trial☆ Mojca Lunder a, b,⁎, Miodrag Janić a, Borut Jug a, Mišo Šabovič a a b
Department of Vascular Disease, University of Ljubljana Medical Centre, Zaloška 7, 1000 Ljubljana, Slovenia Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine, University of Ljubljana, Korytkova 2, 1000 Ljubljana, Slovenia
a r t i c l e
i n f o
Article history: Received 12 September 2011 Received in revised form 17 November 2011 Accepted 21 November 2011 Available online 12 December 2011 Keywords: Arterial stiffness Arterial ageing Endothelial dysfunction Fluvastatin Valsartan Prevention
a b s t r a c t Background: Ageing progressively diminishes arterial functions, even in the absence of traditional risk factors. Our aim was to explore whether age-related arterial changes in middle-aged males could be reversed using short-term, low-dose fluvastatin/valsartan combination intervention. Methods: Forty apparently healthy, middle-aged males (43.3 ± 5.8 years) were recruited in a double-blind, randomised intervention. Individuals received either 10 mg fluvastatin/20 mg valsartan daily or placebo over 30 days. The brachial artery flow mediated dilation (FMD), pulse wave velocity (PWV) and common carotid artery β-stiffness were assessed at baseline and after 30 days, and again 5–10 months after therapy discontinuation. Results: Arterial function variables significantly improved after 30 days of intervention; FMD improved by 167.7% (P b 0.001), PWV by 10.9% (P b 0.05) and β-stiffness by 18.8% (P b 0.01), whereas no changes were obtained in the placebo group. The favourable outcomes in the intervention group were accompanied by a significant decrease of high sensitivity-C reactive protein levels (1.8-fold; P b 0.05). In contrast, lipids and blood pressure remained unchanged. Surprisingly, the beneficial arterial effects were still present to a substantial degree 7 months after completing intervention (remaining % of initial improvement: FMD 82.1%, PWV 69.5% and β-stiffness 68.5%), but declined substantially after 10 months. Conclusion: Our results indicate that age-related arterial changes, at least in middle-aged males, can be reversed. Short-term treatment with a low-dose fluvastatin/valsartan combination resulted in a large and long lasting improvement of arterial function. © 2011 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.
1. Introduction Atherosclerosis and its consequences remain the leading cause of morbidity and mortality in developed countries despite current management strategies [1,2]. Ageing makes the arteries more susceptible to development of atherosclerosis and other cardiovascular diseases [3,4]. Arterial ageing is accompanied by progressive functional and morphological changes, which lead to slow and gradual impairment in arterial function and structure [1,5,6]. Impaired endothelial function, loss of arterial elasticity and reduced arterial compliance are among the most prominent hallmarks of arterial ageing [2,7]. Since ageing is undoubtedly an important risk factor, prevention approaches and strategies focused on arterial ageing are of great interest. However, the prevention of arterial ageing has not yet been extensively investigated.
☆ Grant: The present study was supported by the Slovenian Research Agency, Ljubljana Slovenia [research project L3-2293]. ⁎ Corresponding author at: Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine, University of Ljubljana, Korytkova 2, SI-1000 Ljubljana, Slovenia. Tel.: + 386 15437353; fax: + 386 15437331. E-mail address: [email protected] (M. Lunder).
Taking into clinical consideration the process of arterial ageing, one could claim with certainty the following: a 55-year old healthy individual has functionally and morphologically older arteries (that are very likely more susceptible to the development of atherosclerosis) than a 35-year old individual [3,4]. It seems fairly reasonable to attempt to slow down or even reverse the process of arterial ageing, certainly if at all possible. Of course, this aim should include the standard creed for preventive interventions: the earlier the better. Beside their primary mode of action (focused on lipids and blood pressure) statins and angiotensin receptor blockers (ARBs or sartans) have additional beneficial effects, known as pleiotropic effects. Of particular interest are the so-called vascular pleiotropic effects. Thus, they could improve endothelial function, act as antioxidants, have immunomodulatory activity, etc. [8–12]. The described effects could result in improvement of vascular function. It should be emphasized that the combination of a statin and an ARB, particularly fluvastatin and valsartan, provides additive [13] or even synergistic [14,15] pleiotropic effects by both distinct and interrelated mechanisms operating on the vascular function; this has been documented in cell cultures, animals and in patients with cardiovascular risk factors. However, possible low-dose effects in humans have not been investigated, nor
0953-6205/$ – see front matter © 2011 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved. doi:10.1016/j.ejim.2011.11.011
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has the population of healthy middle-aged males been explored in regard to possible improvement of vascular function. In our previous published and unpublished studies [16,17] we showed that age-related arterial wall changes are reversible with separate subtherapeutic, low-dose fluvastatin or valsartan intervention. Based on the data obtained we assumed that combining both drugs might be even more effective than each drug separately, especially in the case of prolonged effects after therapy discontinuation. Therefore, the aim of the present study was to test to what extent a lowdose combination of fluvastatin/valsartan could improve age-related impairment of endothelial function and arterial stiffness in apparently healthy, middle-aged subjects, and how long the effect would last after therapy discontinuation. 2. Methods
subjects of the intervention group 5, 7 and 10 months after therapy discontinuation. A single experienced examiner using an Aloka ProSound Alpha 10 echo-machine with an incorporated automatic highresolution eTracking system, which is independent of investigator bias, performed all the measurements. They were carried out at the same time of day for each participant, in ensured standardised, temperature-controlled conditions (24 °C), constant air humidity and in a calm environment. Participants were asked not to perform strenuous physical activities one day before the ultrasound measurements, to fast overnight for at least 8 h and to abstain from alcohol and caffeine for at least 12 h. Upon arrival, they were asked to rest for 10 min in a supine position, thus ensuring acclimatisation. Blood pressure was obtained from the left arm before the ultrasound measurements, using an automated sphygmomanometer (Welch Allyn Speidel & Keller). Electrocardiogram (ECG) electrodes were then attached and the ECG was recorded throughout the ultrasound measurements.
2.1. Trial design This was a double blind, placebo-controlled study with balanced randomization (1:1) conducted in Slovenia (Europe). No changes to methods were made after trial commencement. The study was approved by the Slovenian National Medical Ethics Committee and informed consent was obtained from all participants. 2.2. Participants In this study, 40 apparently healthy, middle-aged males were recruited from the Slovenian population. The participants were recruited through local advertisements. Inclusion criteria were male gender and age between 30 and 50 years; exclusion criteria were smoking, a history of arterial hypertension, hypercholesterolemia, diabetes mellitus and other cardiovascular diseases, chronic medical conditions and regular medication therapy. Women were not included in the study in order to avoid menstrual cycle hormonal fluctuations, which could interfere with the blood vessels' reactivity and consequently ultrasound measurements. The participants were asked to maintain their usual lifestyle habits unchanged throughout the study (intervention and follow-up period) in order to avoid any confounding effects on measured variables by lifestyle modification. This was checked by personal interviews on every occasion before ultrasound measurements were performed.
2.5.1. Brachial artery flow-mediated dilation (FMD) The measurement of brachial artery FMD was performed in accordance with the published guidelines [18,19]. Participants were asked to extend their right arm, which was immobilized with foam rubber and supported at an angle of 80° from the body. A pneumatic cuff was placed around the forearm of the extended arm. After visualization of the right brachial artery 3 to 6 cm above the elbow, the echo-probe was attached to the holder, thus enabling continuous tracking and recording of the brachial artery diameter, without any interruptions throughout the whole measurement procedure. Following measurement of the baseline brachial artery diameter, which lasted for 1 min, the forearm pneumatic cuff was inflated to 50 mm Hg above the systolic pressure for 4 min, causing complete arterial occlusion. After the occlusion period, the cuff was quickly deflated, inducing reactive hyperaemia. The diameter of the brachial artery was then recorded for another 3 min. The image and diameter of the brachial artery were recorded continuously before, throughout and after the occlusion period. After the measurement, the echo-machine automatically revealed the baseline diameter, as well as the maximal dilation diameter and calculated the FMD, providing it as a percentage of change relative to the baseline diameter.
Participants were randomly assigned to receive either placebo (placebo group; n = 20) or a combination of fluvastatin (10 mg daily) and valsartan (20 mg daily) (intervention group; n = 20) during a period of 30 days. Tablets were packed in numbered containers. The participants were asked to take the tablets orally with a glass of water, every morning before breakfast; drug compliance was assured by pill counting. Participants were asked to bring their numbered containers at the end of the intervention period (30th day of the therapy). The containers were then opened and the residual pills were counted by the examiner.
2.5.2. Pulse wave velocity (PWV) and carotid artery β stiffness Measurements of PWV and common carotid artery β stiffness were performed on the right common carotid artery. The participants lay in the supine position, with the head elevated to around 45° and tilted to around 30° to the left. The Aloka echo-machine used in our study was also equipped with special software for automatic determination of the PWV and carotid stiffness through pulse wave analysis [3]. After visualisation of the right common carotid artery, the cursor pair of the measuring device was placed on the anterior and posterior walls of the common carotid artery, approximately 2 cm before the bifurcation. Pressure waveforms were obtained noninvasively, using arterial diameter change waveforms calibrated automatically on the basis of systolic and diastolic blood pressure values. PWV and β-stiffness were automatically calculated as means of twelve beats.
2.4. Outcomes
2.6. Laboratory analysis of blood samples
Pre-specified primary outcomes were flow-mediated dilation (FMD), pulse wave velocity (PWV) and ß-stiffness. After the trial commenced, no changes to trial outcomes were made.
Fasting venous blood samples were obtained at the beginning (day 0) and at the end (day 30) of the treatment period with the low-dose fluvastatin/valsartan combination or placebo. Blood glucose, electrolytes, cholesterol, triglycerides and high sensitivity-C reactive protein (hs-CRP) were measured in blood serum using the VITROS 5,1FS Chemistry system — validated method and laboratory system (Ortho Clinical Diagnosis, Inc.). Total cholesterol and triglycerides levels were measured using the above mentioned machine, while the values of LDL-cholesterol were calculated using the Friedewald equation.
2.3. Interventions
2.5. Assessment of endothelial function Ultrasound measurements for endothelial function assessment were performed at the beginning (day 0) and at the end (day 30) of the treatment period with the low-dose fluvastatin/valsartan combination or placebo. Follow-up ultrasound measurements were performed in all
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2.7. Sample size
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Table 1 Baseline characteristics of the 40 subjects enrolled in the study.
We chose a sample size of 40 participants in the light of our previous studies in which we obtained statistically significant changes between the intervention and placebo groups, while the power of the studies were sufficiently high. The correctness of the estimation of the study population was proven by an analysis of the power of the study, presented in the section “Statistical methods”.
Characteristic
Value
General characteristics Age (years) Gender Systolic BP (mm Hg) Diastolic BP (mm Hg) Heart rate (b.p.m.)
43.3 ± 5.8 male 124.0 ± 1.2 74.9 ± 1.9 60.3 ± 1.8
2.8. Randomisation
Laboratory investigations Total cholesterol (mmol/l) LDL cholesterol (mmol/l) HDL cholesterol (mmol/l) Triglycerides (mmol/l) Plasma glucose (mmol/l) Hs-CRP (mg/l)
5.7 ± 0.4 3.6 ± 0.2 1.4 ± 0.1 1.4 ± 0.1 5.0 ± 0.2 1.3 ± 0.2
Ultrasound measurements FMD (%) PWV (m/s) ß stiffness (U)
2.2 ± 0.3 5.8 ± 0.2 7.2 ± 0.2
An independent pharmacist, who was not clinically involved in the study, packed containers with either placebo or the fluvastatin/ valsartan combination and numbered them according to a simple randomization procedure (computerized random numbers). The substances, combination or placebo, were in the form of tablets identical in appearance, packed in the same white, opaque containers. The key to resolving the content of each numbered container was stored in the safe deposit box of the pharmacist. Each participant was assigned an order number and received the corresponding prepacked container according to the simple randomization procedure. The allocation sequence obtained was concealed from the researchers enrolling and assessing participants in a sealed envelope. The envelope was kept in possession of the independent medical student, who also enrolled the participants to the study. The same independent medical student carried out the implementation procedure. 2.9. Statistical methods All values were expressed as means ± SEM and were normally distributed. Differences between values recorded at the beginning (0th day) and at the end of the study (30th day) were assessed by oneway analysis of variance (ANOVA). When a significant interaction was present, the Bonferroni post-test was performed. A P-value of less than 0.05 was considered significant. Correlations between changes in hs-CRP levels and changes in measured ultrasound variables were calculated using Pearson correlation coefficients. All statistical analyses were performed using Graph Pad Prism 5.0 software. A power analysis for the difference between the placebo and the intervention group for FMD, PWV and β stiffness was also conducted. Parameters needed for the power analysis, i.e. the difference between groups and standard deviations, were estimated from the sample. A power of 99.9%, 92.5% and 97.0% was achieved when FMD, PWV and β stiffness were used as a response, respectively. 3. Results The baseline characteristics of all 40 subjects included in the study are shown in Table 1. Subject characteristics at the beginning and at the end of the study in both groups are shown in Table 2. No significant differences in systolic and diastolic blood pressure, heart rate, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides and glucose concentration were observed between the placebo and intervention group. There were no adverse events reported by participants. The compliance of the participants was complete; they consumed all pills prepared in the containers. At inclusion in the study, 80% of participants had FMD less than 4%. After the intervention period with the low-dose fluvastatin/valsartan combination, FMD increased by 167.7% (5.8 [95% CI 5.10–6.58]; P b 0.001; Fig. 1A), PWV decreased by 10.9% (5.2 [95% CI 4.94–5.54]; P b 0.05; Fig. 1B) and β stiffness of the carotid artery decreased by 18.8% (5.9 [95% CI 5.47–6.51]; P b 0.01; Fig. 1C). An improvement was observed in every subject of the intervention group in all measured ultrasound variables. A significant 1.8-fold decrease in hs-CRP levels was observed after 30 days of low-dose fluvastatin/valsartan
All values are expressed as means ± SEM. BP: blood pressure; b.p.m.: beats per minute; LDL: low-density lipoprotein; HDL: high-density lipoprotein; hs-CRP: high sensitivity C-reactive protein; FMD: flow-mediated dilation of brachial artery; PWV: pulse wave velocity.
treatment compared to the placebo group (0.71 [95% CI 0.53–0.89]; P b 0.05; Fig. 1D]). We observed no significant changes in the same variables in the placebo group throughout the study (Fig. 1). No significant correlations were observed between hs-CRP change and change in FMD (R = 0.12, − 0.03), PWV (R = 0.14, −0.25) or β stiffness (R = 0.22, −0.29) in the placebo or intervention groups, respectively. Follow-up ultrasound measurements were repeated 5, 7 and 10 months after therapy discontinuation in all participants of the intervention group. There was evidence of a significant residual effect still being present even 5–7 months after therapy discontinuation. In the 10th month after therapy discontinuation, the effect had declined. The percentages of residual improvement of the measured variables are shown in Fig. 2. 4. Discussion In the present study we sought to explore the hypothesis, based on our preliminary unpublished data, that a low-dose combination of fluvastatin/valsartan has favourable effects on ageing-associated arterial impairment in middle-aged healthy males. In brief, we confirmed the hypothesis and proved that intervention with a low-dose Table 2 Subject characteristics in the placebo and in the intervention groups. Placebo group (n = 20)
Intervention group (n = 20)
0th day
0th day
30th day
P value
30th day
Systolic BP (mm Hg) 123.3±1.8 120.8±1.5 124.4±1.3 120.3±1.8 Diastolic BP (mm Hg) 73.5 ± 2.4 72.4 ± 2.3 75.1 ± 1.4 72.2 ± 1.5 Heart rate (b.p.m.) 61.1 ± 2.2 60.3 ± 1.8 59.5 ± 2.5 59.7 ± 2.0 Total cholesterol 5.7 ± 0.3 5.6 ± 0.3 5.6 ± 0.3 5.3 ± 0.2 (mmol/l) LDL cholesterol 3.6 ± 0.2 3.6 ± 0.3 3.7 ± 0.2 3.1 ± 0.3 (mmol/l) HDL cholesterol 1.4 ± 0.1 1.4 ± 0.1 1.4 ± 0.1 1.4 ± 0.1 (mmol/l) Triglycerides (mmol/l) 1.3 ± 0.1 1.4 ± 0.2 1.4 ± 0.2 1.5 ± 0.2 Plasma glucose 4.9 ± 0.2 4.9 ± 0.2 5.1 ± 0.1 4.9 ± 0.2 (mmol/l)
0.21 0.43 0.95 0.35 0.14 0.99 0.87 0.73
All values are expressed as means ± SEM. BP: blood pressure; b.p.m.: beats per minute; LDL: low-density lipoprotein; HDL: high-density lipoprotein.
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A
B Fig. 2. Residual effects (expressed as percentage) of brachial artery flow mediated dilation (FMD), pulse wave velocity (PWV) and ß-stiffness index 5, 7 and 10 months after lowdose fluvastatin/valsartan therapy discontinuation. Values are expressed as means ± SEM.
C
D
Fig. 1. Absolute values of A) brachial artery flow mediated dilation (FMD), B) pulse wave velocity (PWV), C) ß-stiffness index and D) high sensitivity C-reactive protein (hs-CRP) values in the placebo and the intervention group at the beginning (white bars) and at the end of the study (grey bars). Values are expressed as means ± SEM. * P b 0.05, ** P b 0.01 and *** P b 0.001 refer to the comparison between intervention and placebo group after 30 days of intervention.
combination of fluvastatin/valsartan produced a significant improvement of vascular functions (FMD, PWV and β stiffness). In other words, the intervention resulted in restoration of the slightly impaired endothelial function to normal levels, whereas arterial stiffness variables improved to values expected to be present in approximately 10–15 years younger individuals. Importantly, the positive effects of intervention were still present after withdrawal of drug therapy, being detectable even after approximately 7 months to a substantial degree, though of course, lower than after 30 days of intervention. In the present study vascular function was the target for the intervention; therefore drugs (fluvastatin and valsartan) with well-documented beneficial pleiotropic effects on vascular function were chosen [8–10]. Numerous previous studies have shown that the combination of a statin and an ARB i.e. fluvastatin and valsartan, in therapeutic doses improves vascular function [15,20,21]. Both additive [13] and synergistic [14,15] effects were attributed to a combination of fluvastatin and valsartan. The novelty in regard to fluvastatin and valsartan administration in the study presented was the use of very low, subtherapeutic doses of the drug combination (fluvastatin 10 mg, valsartan 20 mg). Namely, we assumed that low-doses of these drugs would be sufficient and efficacious in improving the initial, slight deterioration of arterial function already present in middle-aged, apparently healthy males. Whether such or any other intervention would be efficient in long-term improvement of vascular function in an apparently healthy middle-aged population has to date not been the focus of any research. As mentioned above, we assumed that in healthy individuals a low-dose combination (15–25% of the recommended therapeutic doses) could achieve a significant improvement in arterial functions. Indeed, the improvement of endothelial function and arterial stiffness was observed in every single individual of the intervention group in our study, thus suggesting that the low-dose combination of fluvastatin/valsartan could in fact alleviate arterial ageing. Arterial ageing reflects the general age-related decline of biological function that is accelerated by traditional cardiovascular risk factors and alleviated by interventions aimed at counteracting them [1]. Several mechanisms including senescence of the cardiovascular tissues at the cellular level and systemic derangements such as oxidative stress and chronic low-grade inflammation have been proposed as precipitators of age-related vascular function deterioration [5]. The very beneficial effects of a low-dose combination fluvastatin/valsartan obtained are likely the consequence of various mechanisms. Fluvastatin and valsartan have similar pleiotropic effects, which are amplified in the presence of both drugs [9,10,22]. The primary mechanism underlying the observed beneficial effects could be an increase in the bioavailability of nitric oxide, leading to improved endothelium-dependent vasodilation and consequently improved endothelial function [23]. We found a substantial improvement
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of FMD during intervention. It is somewhat surprising, but very important, that at the beginning of the study 80% of individuals already had importantly impaired endothelial function according to their measured FMD. The decrease of age-related high arterial oxidative stress and/or inflammation could be the other possible mechanism underlying the success of our intervention. The proposed mechanism could originate in the beneficial effect of statins in increasing NO synthesis and also the synergistic effect of statins and sartans on decreasing angiotensin II expression. Other non-identified or unknown mechanisms could also be involved. In the present study we unexpectedly found a significant decrease in hs-CRP during treatment with the low-dose fluvastatin/ valsartan combination. This finding could at least partially explain the mechanism(s) underlying the success of the described intervention. The changes in hs-CRP levels did not correlate with changes in FMD, PWV or ß stiffness. Considering the fact that hs-CRP is a nonspecific variable affected by numerous factors, the absence of correlations is not unexpected. In view of our results and our tested population, the results of the huge, very important JUPITER trial are very relevant. In the JUPITER trial those participants who were basically not considered candidates for statin therapy, nevertheless significantly benefited from it. Thus treatment with rosuvastatin (20 mg/day) resulted in a decrease of cardiovascular events and total mortality in asymptomatic patients with normal values of cholesterol, but increased levels of high-sensitivity Creactive protein [24]. At this stage of research we did not measure other potential mechanisms involved, such as markers of the oxidative stress burden: this represents a limitation of the present study. Clearly further studies with the aim of clarifying the underlying mechanisms are needed. Another very important observation that could have clinical repercussions, is the presence of a prolonged protective effect after discontinuation of intervention, i.e. withdrawal of drugs. The improvement of vascular effects was still detectable at significant levels even after approximately 7 months. This prolonged effect could be due to the increased gene expression responsible for the beneficial vascular effects induced by the intervention. This issue remains to be further explored in the future. Based on this important finding, the proposed approach for delaying age-associated arterial system changes would seem to be the most appropriate in the intermittent, and not continuous, mode. Of course, the intermittent approach has several advantages over the continuous one. We performed similar randomised, placebo-controlled clinical studies with fluvastatin or valsartan separately before the present study [16,17]. Both drugs achieved a significant improvement of vascular function in apparently healthy middle-aged males, but the level and duration of the recorded effects were much lower and shorter than in the case of their combination. Even though a head-to-head comparison was not performed at this stage, the combination of fluvastatin/valsartan appears to be much more effective. This assumption can be interpreted as a result of the previously described potential synergistic effects of their combination. At present a four arms study is underway to definitively answer this question. Treatment with a low-dose combination of fluvastatin/valsartan did not produce any changes in lipids and/or the blood pressure profile. Evidently, the concentrations of drugs were too low to achieve their primary therapeutic effect. Therefore, this regimen probably has an advantageous safety profile. In fact, participants in our study did not report any side-effects. The short-term treatment, the low-dose of drugs and good safety profile should probably result in a high compliance. In our view, the most practical and effective way of application of this approach would be repetition of short-term (1 month) treatment every 6–9 months, since long-term sustained effects were achieved by this intervention. In summary, we conclude that short-term intervention by a lowdose combination fluvastatin/valsartan produces significant and longlasting improvement of age-related impairment of the vascular function in middle-aged, apparently healthy males. The results and conclusions
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of our study should obviously be confirmed in a large clinical trial, and then their external validity and generalizability could and should be established in clinical practice. The described intervention suggests a possible new approach for early prevention of arterial ageing and atherosclerosis. 5. Learning points The aim of the present study was to test to what extent a low-dose combination of fluvastatin/valsartan could improve age-related impairment of endothelial function and arterial stiffness in apparently healthy, middle-aged subjects, and how long the effect would last after therapy discontinuation. The main results were: • Intervention with a low-dose combination of fluvastatin/valsartan produced a significant improvement of vascular functions (FMD, PWV and β stiffness). • The intervention resulted in restoration of the slightly impaired endothelial function to normal levels, whereas arterial stiffness variables improved to values expected to be present in approximately 10–15 years younger individuals. • The beneficial vascular effects of intervention were still present after withdrawal of therapy, being present even after approximately 7 months to a substantial degree. Conflicts of interest The authors declare that they have no conflict of interest. Acknowledgements The authors would like to express their gratitude to Sara Habjan, M.D. for her help in recruiting the volunteers for the study. References [1] Nilsson PM, Boutouyrie P, Laurent S. Vascular aging: a tale of EVA and ADAM in cardiovascular risk assessment and prevention. Hypertension 2009;54:3–10. [2] Pepe S, Lakatta EG. Aging hearts and vessels: masters of adaptation and survival. Cardiovasc Res 2005;66:190–3. [3] Carerj S, Nipote C, Zimbalatti C, Zito C, Sutera Sardo L, Dattilo G, et al. Normal vascular aging evaluated by a new tool: e-tracking. Eur J Echocardiogr 2006:49 [suppl: S]. [4] Lind L. Impact of ageing on the measurement of endothelium-dependent vasodilation. Pharmacol Rep 2006;58(Suppl):41–6. [5] Hadi HA, Carr CS, Al Suwaidi J. Endothelial dysfunction: cardiovascular risk factors, therapy, and outcome. Vasc Health Risk Manag 2005;1:183–98. [6] Wykretowicz A, Gerstenberger P, Guzik P, Milewska A, Krauze T, Adamska K, et al. Arterial stiffness in relation to subclinical atherosclerosis. Eur J Clin Invest 2009;39: 11–6. [7] Laurent S, Cockcroft J, Van Bortel L, Boutouyrie P, Giannattasio C, Hayoz D, et al. Expert consensus document on arterial stiffness: methodological issues and clinical applications. Eur Heart J 2006;27:2588–605. [8] Tomiyama H, Yamashina A. Non-invasive vascular function tests: their pathophysiological background and clinical application. Circ J 2010;74:24–33. [9] Blum A, Shamburek R. The pleiotropic effects of statins on endothelial function, vascular inflammation, immunomodulation and thrombogenesis. Atherosclerosis 2009;203:325–30. [10] Jankowski P, Safar ME, Benetos A. Pleiotropic effects of drugs inhibiting the renin– angiotensin–aldosterone system. Curr Pharm Des 2009;15:571–84. [11] Sugiyama M, Ohashi M, Takase H, Sato K, Ueda R, Dohi Y. Effects of atorvastatin on inflammation and oxidative stress. Heart Vessels 2005;20:133–6. [12] Castilla Guerra L, del Carmen Fernandez Moreno M, Lopez Chozas JM, Jimenez Hernandez MD. Statins in stroke prevention: what an internist should know. Eur J Intern Med 2008;19:8–14. [13] Hussein O, Shneider J, Rosenblat M, Aviram M. Valsartan therapy has additive anti-oxidative effect to that of fluvastatin therapy against low-density lipoprotein oxidation: studies in hypercholesterolemic and hypertensive patients. J Cardiovasc Pharmacol 2002;40:28–34. [14] Horiuchi M, Cui TX, Li Z, Li JM, Nakagami H, Iwai M. Fluvastatin enhances the inhibitory effects of a selective angiotensin II type 1 receptor blocker, valsartan, on vascular neointimal formation. Circulation 2003;107:106–12. [15] Liu L, Zhao SP, Zhou HN, Li QZ, Li JX. Effect of fluvastatin and valsartan, alone and in combination, on postprandial vascular inflammation and fibrinolytic activity in patients with essential hypertension. J Cardiovasc Pharmacol 2007;50:50–5.
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[16] Lunder M, Janic M, Habjan S, Sabovic M. Subtherapeutic, low-dose fluvastatin improves functional and morphological arterial wall properties in apparently healthy, middle-aged males a pilot study. Atherosclerosis 2011;215:446–51. [17] Lunder M, Janic M, Sabovic M. Reduction of age-associated arterial wall changes by lowdose valsartan. Eur J Cardiovasc Prev Rehabil 2011, doi:10.1177/1741826711423104. [18] Corretti MC, Anderson TJ, Benjamin EJ, Celermajer D, Charbonneau F, Creager MA, et al. Guidelines for the ultrasound assessment of endothelial-dependent flowmediated vasodilation of the brachial artery: a report of the International Brachial Artery Reactivity Task Force. J Am Coll Cardiol 2002;39:257–65. [19] Celermajer DS, Sorensen KE, Gooch VM, Spiegelhalter DJ, Miller OI, Sullivan ID, et al. Non-invasive detection of endothelial dysfunction in children and adults at risk of atherosclerosis. Lancet 1992;340:1111–5. [20] Koh KK, Han SH, Oh PC, Shin EK, Quon MJ. Combination therapy for treatment or prevention of atherosclerosis: focus on the lipid-RAAS interaction. Atherosclerosis 2010;209:307–13.
[21] Yoshikawa M, Nakamura K, Nagase S, Sakuragi S, Kusano KF, Matsubara H, et al. Effects of combined treatment with angiotensin II type 1 receptor blocker and statin on stent restenosis. J Cardiovasc Pharmacol 2009;53:179–86. [22] van Haelst PL, van Doormaal JJ, May JF, Gans RO, Crijns HJ, Tervaert JW. Secondary prevention with fluvastatin decreases levels of adhesion molecules, neopterin and C-reactive protein. Eur J Intern Med 2001;12:503–9. [23] Skogastierna C, Luksha L, Kublickiene K, Eliasson E, Rane A, Ekstrom L. Beneficial vasoactive endothelial effects of fluvastatin: focus on prostacyclin and nitric oxide. Heart Vessels 2011, doi:10.1007/s00380-010-0097-x. [24] Ridker PM, MacFadyen JG, Fonseca FA, Genest J, Gotto AM, Kastelein JJ, et al. Number needed to treat with rosuvastatin to prevent first cardiovascular events and death among men and women with low low-density lipoprotein cholesterol and elevated high-sensitivity C-reactive protein: justification for the use of statins in prevention: an intervention trial evaluating rosuvastatin (JUPITER). Circ Cardiovasc Qual Outcomes 2009;2:616–23.
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European Journal of Internal Medicine journal homepage: www.elsevier.com/locate/ejim
Original article
The effects of low-dose fluvastatin and valsartan combination on arterial function: A randomized clinical trial☆ Mojca Lunder a, b,⁎, Miodrag Janić a, Borut Jug a, Mišo Šabovič a a b
Department of Vascular Disease, University of Ljubljana Medical Centre, Zaloška 7, 1000 Ljubljana, Slovenia Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine, University of Ljubljana, Korytkova 2, 1000 Ljubljana, Slovenia
a r t i c l e
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Article history: Received 12 September 2011 Received in revised form 17 November 2011 Accepted 21 November 2011 Available online 12 December 2011 Keywords: Arterial stiffness Arterial ageing Endothelial dysfunction Fluvastatin Valsartan Prevention
a b s t r a c t Background: Ageing progressively diminishes arterial functions, even in the absence of traditional risk factors. Our aim was to explore whether age-related arterial changes in middle-aged males could be reversed using short-term, low-dose fluvastatin/valsartan combination intervention. Methods: Forty apparently healthy, middle-aged males (43.3 ± 5.8 years) were recruited in a double-blind, randomised intervention. Individuals received either 10 mg fluvastatin/20 mg valsartan daily or placebo over 30 days. The brachial artery flow mediated dilation (FMD), pulse wave velocity (PWV) and common carotid artery β-stiffness were assessed at baseline and after 30 days, and again 5–10 months after therapy discontinuation. Results: Arterial function variables significantly improved after 30 days of intervention; FMD improved by 167.7% (P b 0.001), PWV by 10.9% (P b 0.05) and β-stiffness by 18.8% (P b 0.01), whereas no changes were obtained in the placebo group. The favourable outcomes in the intervention group were accompanied by a significant decrease of high sensitivity-C reactive protein levels (1.8-fold; P b 0.05). In contrast, lipids and blood pressure remained unchanged. Surprisingly, the beneficial arterial effects were still present to a substantial degree 7 months after completing intervention (remaining % of initial improvement: FMD 82.1%, PWV 69.5% and β-stiffness 68.5%), but declined substantially after 10 months. Conclusion: Our results indicate that age-related arterial changes, at least in middle-aged males, can be reversed. Short-term treatment with a low-dose fluvastatin/valsartan combination resulted in a large and long lasting improvement of arterial function. © 2011 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.
1. Introduction Atherosclerosis and its consequences remain the leading cause of morbidity and mortality in developed countries despite current management strategies [1,2]. Ageing makes the arteries more susceptible to development of atherosclerosis and other cardiovascular diseases [3,4]. Arterial ageing is accompanied by progressive functional and morphological changes, which lead to slow and gradual impairment in arterial function and structure [1,5,6]. Impaired endothelial function, loss of arterial elasticity and reduced arterial compliance are among the most prominent hallmarks of arterial ageing [2,7]. Since ageing is undoubtedly an important risk factor, prevention approaches and strategies focused on arterial ageing are of great interest. However, the prevention of arterial ageing has not yet been extensively investigated.
☆ Grant: The present study was supported by the Slovenian Research Agency, Ljubljana Slovenia [research project L3-2293]. ⁎ Corresponding author at: Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine, University of Ljubljana, Korytkova 2, SI-1000 Ljubljana, Slovenia. Tel.: + 386 15437353; fax: + 386 15437331. E-mail address: [email protected] (M. Lunder).
Taking into clinical consideration the process of arterial ageing, one could claim with certainty the following: a 55-year old healthy individual has functionally and morphologically older arteries (that are very likely more susceptible to the development of atherosclerosis) than a 35-year old individual [3,4]. It seems fairly reasonable to attempt to slow down or even reverse the process of arterial ageing, certainly if at all possible. Of course, this aim should include the standard creed for preventive interventions: the earlier the better. Beside their primary mode of action (focused on lipids and blood pressure) statins and angiotensin receptor blockers (ARBs or sartans) have additional beneficial effects, known as pleiotropic effects. Of particular interest are the so-called vascular pleiotropic effects. Thus, they could improve endothelial function, act as antioxidants, have immunomodulatory activity, etc. [8–12]. The described effects could result in improvement of vascular function. It should be emphasized that the combination of a statin and an ARB, particularly fluvastatin and valsartan, provides additive [13] or even synergistic [14,15] pleiotropic effects by both distinct and interrelated mechanisms operating on the vascular function; this has been documented in cell cultures, animals and in patients with cardiovascular risk factors. However, possible low-dose effects in humans have not been investigated, nor
0953-6205/$ – see front matter © 2011 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved. doi:10.1016/j.ejim.2011.11.011
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has the population of healthy middle-aged males been explored in regard to possible improvement of vascular function. In our previous published and unpublished studies [16,17] we showed that age-related arterial wall changes are reversible with separate subtherapeutic, low-dose fluvastatin or valsartan intervention. Based on the data obtained we assumed that combining both drugs might be even more effective than each drug separately, especially in the case of prolonged effects after therapy discontinuation. Therefore, the aim of the present study was to test to what extent a lowdose combination of fluvastatin/valsartan could improve age-related impairment of endothelial function and arterial stiffness in apparently healthy, middle-aged subjects, and how long the effect would last after therapy discontinuation. 2. Methods
subjects of the intervention group 5, 7 and 10 months after therapy discontinuation. A single experienced examiner using an Aloka ProSound Alpha 10 echo-machine with an incorporated automatic highresolution eTracking system, which is independent of investigator bias, performed all the measurements. They were carried out at the same time of day for each participant, in ensured standardised, temperature-controlled conditions (24 °C), constant air humidity and in a calm environment. Participants were asked not to perform strenuous physical activities one day before the ultrasound measurements, to fast overnight for at least 8 h and to abstain from alcohol and caffeine for at least 12 h. Upon arrival, they were asked to rest for 10 min in a supine position, thus ensuring acclimatisation. Blood pressure was obtained from the left arm before the ultrasound measurements, using an automated sphygmomanometer (Welch Allyn Speidel & Keller). Electrocardiogram (ECG) electrodes were then attached and the ECG was recorded throughout the ultrasound measurements.
2.1. Trial design This was a double blind, placebo-controlled study with balanced randomization (1:1) conducted in Slovenia (Europe). No changes to methods were made after trial commencement. The study was approved by the Slovenian National Medical Ethics Committee and informed consent was obtained from all participants. 2.2. Participants In this study, 40 apparently healthy, middle-aged males were recruited from the Slovenian population. The participants were recruited through local advertisements. Inclusion criteria were male gender and age between 30 and 50 years; exclusion criteria were smoking, a history of arterial hypertension, hypercholesterolemia, diabetes mellitus and other cardiovascular diseases, chronic medical conditions and regular medication therapy. Women were not included in the study in order to avoid menstrual cycle hormonal fluctuations, which could interfere with the blood vessels' reactivity and consequently ultrasound measurements. The participants were asked to maintain their usual lifestyle habits unchanged throughout the study (intervention and follow-up period) in order to avoid any confounding effects on measured variables by lifestyle modification. This was checked by personal interviews on every occasion before ultrasound measurements were performed.
2.5.1. Brachial artery flow-mediated dilation (FMD) The measurement of brachial artery FMD was performed in accordance with the published guidelines [18,19]. Participants were asked to extend their right arm, which was immobilized with foam rubber and supported at an angle of 80° from the body. A pneumatic cuff was placed around the forearm of the extended arm. After visualization of the right brachial artery 3 to 6 cm above the elbow, the echo-probe was attached to the holder, thus enabling continuous tracking and recording of the brachial artery diameter, without any interruptions throughout the whole measurement procedure. Following measurement of the baseline brachial artery diameter, which lasted for 1 min, the forearm pneumatic cuff was inflated to 50 mm Hg above the systolic pressure for 4 min, causing complete arterial occlusion. After the occlusion period, the cuff was quickly deflated, inducing reactive hyperaemia. The diameter of the brachial artery was then recorded for another 3 min. The image and diameter of the brachial artery were recorded continuously before, throughout and after the occlusion period. After the measurement, the echo-machine automatically revealed the baseline diameter, as well as the maximal dilation diameter and calculated the FMD, providing it as a percentage of change relative to the baseline diameter.
Participants were randomly assigned to receive either placebo (placebo group; n = 20) or a combination of fluvastatin (10 mg daily) and valsartan (20 mg daily) (intervention group; n = 20) during a period of 30 days. Tablets were packed in numbered containers. The participants were asked to take the tablets orally with a glass of water, every morning before breakfast; drug compliance was assured by pill counting. Participants were asked to bring their numbered containers at the end of the intervention period (30th day of the therapy). The containers were then opened and the residual pills were counted by the examiner.
2.5.2. Pulse wave velocity (PWV) and carotid artery β stiffness Measurements of PWV and common carotid artery β stiffness were performed on the right common carotid artery. The participants lay in the supine position, with the head elevated to around 45° and tilted to around 30° to the left. The Aloka echo-machine used in our study was also equipped with special software for automatic determination of the PWV and carotid stiffness through pulse wave analysis [3]. After visualisation of the right common carotid artery, the cursor pair of the measuring device was placed on the anterior and posterior walls of the common carotid artery, approximately 2 cm before the bifurcation. Pressure waveforms were obtained noninvasively, using arterial diameter change waveforms calibrated automatically on the basis of systolic and diastolic blood pressure values. PWV and β-stiffness were automatically calculated as means of twelve beats.
2.4. Outcomes
2.6. Laboratory analysis of blood samples
Pre-specified primary outcomes were flow-mediated dilation (FMD), pulse wave velocity (PWV) and ß-stiffness. After the trial commenced, no changes to trial outcomes were made.
Fasting venous blood samples were obtained at the beginning (day 0) and at the end (day 30) of the treatment period with the low-dose fluvastatin/valsartan combination or placebo. Blood glucose, electrolytes, cholesterol, triglycerides and high sensitivity-C reactive protein (hs-CRP) were measured in blood serum using the VITROS 5,1FS Chemistry system — validated method and laboratory system (Ortho Clinical Diagnosis, Inc.). Total cholesterol and triglycerides levels were measured using the above mentioned machine, while the values of LDL-cholesterol were calculated using the Friedewald equation.
2.3. Interventions
2.5. Assessment of endothelial function Ultrasound measurements for endothelial function assessment were performed at the beginning (day 0) and at the end (day 30) of the treatment period with the low-dose fluvastatin/valsartan combination or placebo. Follow-up ultrasound measurements were performed in all
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2.7. Sample size
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Table 1 Baseline characteristics of the 40 subjects enrolled in the study.
We chose a sample size of 40 participants in the light of our previous studies in which we obtained statistically significant changes between the intervention and placebo groups, while the power of the studies were sufficiently high. The correctness of the estimation of the study population was proven by an analysis of the power of the study, presented in the section “Statistical methods”.
Characteristic
Value
General characteristics Age (years) Gender Systolic BP (mm Hg) Diastolic BP (mm Hg) Heart rate (b.p.m.)
43.3 ± 5.8 male 124.0 ± 1.2 74.9 ± 1.9 60.3 ± 1.8
2.8. Randomisation
Laboratory investigations Total cholesterol (mmol/l) LDL cholesterol (mmol/l) HDL cholesterol (mmol/l) Triglycerides (mmol/l) Plasma glucose (mmol/l) Hs-CRP (mg/l)
5.7 ± 0.4 3.6 ± 0.2 1.4 ± 0.1 1.4 ± 0.1 5.0 ± 0.2 1.3 ± 0.2
Ultrasound measurements FMD (%) PWV (m/s) ß stiffness (U)
2.2 ± 0.3 5.8 ± 0.2 7.2 ± 0.2
An independent pharmacist, who was not clinically involved in the study, packed containers with either placebo or the fluvastatin/ valsartan combination and numbered them according to a simple randomization procedure (computerized random numbers). The substances, combination or placebo, were in the form of tablets identical in appearance, packed in the same white, opaque containers. The key to resolving the content of each numbered container was stored in the safe deposit box of the pharmacist. Each participant was assigned an order number and received the corresponding prepacked container according to the simple randomization procedure. The allocation sequence obtained was concealed from the researchers enrolling and assessing participants in a sealed envelope. The envelope was kept in possession of the independent medical student, who also enrolled the participants to the study. The same independent medical student carried out the implementation procedure. 2.9. Statistical methods All values were expressed as means ± SEM and were normally distributed. Differences between values recorded at the beginning (0th day) and at the end of the study (30th day) were assessed by oneway analysis of variance (ANOVA). When a significant interaction was present, the Bonferroni post-test was performed. A P-value of less than 0.05 was considered significant. Correlations between changes in hs-CRP levels and changes in measured ultrasound variables were calculated using Pearson correlation coefficients. All statistical analyses were performed using Graph Pad Prism 5.0 software. A power analysis for the difference between the placebo and the intervention group for FMD, PWV and β stiffness was also conducted. Parameters needed for the power analysis, i.e. the difference between groups and standard deviations, were estimated from the sample. A power of 99.9%, 92.5% and 97.0% was achieved when FMD, PWV and β stiffness were used as a response, respectively. 3. Results The baseline characteristics of all 40 subjects included in the study are shown in Table 1. Subject characteristics at the beginning and at the end of the study in both groups are shown in Table 2. No significant differences in systolic and diastolic blood pressure, heart rate, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides and glucose concentration were observed between the placebo and intervention group. There were no adverse events reported by participants. The compliance of the participants was complete; they consumed all pills prepared in the containers. At inclusion in the study, 80% of participants had FMD less than 4%. After the intervention period with the low-dose fluvastatin/valsartan combination, FMD increased by 167.7% (5.8 [95% CI 5.10–6.58]; P b 0.001; Fig. 1A), PWV decreased by 10.9% (5.2 [95% CI 4.94–5.54]; P b 0.05; Fig. 1B) and β stiffness of the carotid artery decreased by 18.8% (5.9 [95% CI 5.47–6.51]; P b 0.01; Fig. 1C). An improvement was observed in every subject of the intervention group in all measured ultrasound variables. A significant 1.8-fold decrease in hs-CRP levels was observed after 30 days of low-dose fluvastatin/valsartan
All values are expressed as means ± SEM. BP: blood pressure; b.p.m.: beats per minute; LDL: low-density lipoprotein; HDL: high-density lipoprotein; hs-CRP: high sensitivity C-reactive protein; FMD: flow-mediated dilation of brachial artery; PWV: pulse wave velocity.
treatment compared to the placebo group (0.71 [95% CI 0.53–0.89]; P b 0.05; Fig. 1D]). We observed no significant changes in the same variables in the placebo group throughout the study (Fig. 1). No significant correlations were observed between hs-CRP change and change in FMD (R = 0.12, − 0.03), PWV (R = 0.14, −0.25) or β stiffness (R = 0.22, −0.29) in the placebo or intervention groups, respectively. Follow-up ultrasound measurements were repeated 5, 7 and 10 months after therapy discontinuation in all participants of the intervention group. There was evidence of a significant residual effect still being present even 5–7 months after therapy discontinuation. In the 10th month after therapy discontinuation, the effect had declined. The percentages of residual improvement of the measured variables are shown in Fig. 2. 4. Discussion In the present study we sought to explore the hypothesis, based on our preliminary unpublished data, that a low-dose combination of fluvastatin/valsartan has favourable effects on ageing-associated arterial impairment in middle-aged healthy males. In brief, we confirmed the hypothesis and proved that intervention with a low-dose Table 2 Subject characteristics in the placebo and in the intervention groups. Placebo group (n = 20)
Intervention group (n = 20)
0th day
0th day
30th day
P value
30th day
Systolic BP (mm Hg) 123.3±1.8 120.8±1.5 124.4±1.3 120.3±1.8 Diastolic BP (mm Hg) 73.5 ± 2.4 72.4 ± 2.3 75.1 ± 1.4 72.2 ± 1.5 Heart rate (b.p.m.) 61.1 ± 2.2 60.3 ± 1.8 59.5 ± 2.5 59.7 ± 2.0 Total cholesterol 5.7 ± 0.3 5.6 ± 0.3 5.6 ± 0.3 5.3 ± 0.2 (mmol/l) LDL cholesterol 3.6 ± 0.2 3.6 ± 0.3 3.7 ± 0.2 3.1 ± 0.3 (mmol/l) HDL cholesterol 1.4 ± 0.1 1.4 ± 0.1 1.4 ± 0.1 1.4 ± 0.1 (mmol/l) Triglycerides (mmol/l) 1.3 ± 0.1 1.4 ± 0.2 1.4 ± 0.2 1.5 ± 0.2 Plasma glucose 4.9 ± 0.2 4.9 ± 0.2 5.1 ± 0.1 4.9 ± 0.2 (mmol/l)
0.21 0.43 0.95 0.35 0.14 0.99 0.87 0.73
All values are expressed as means ± SEM. BP: blood pressure; b.p.m.: beats per minute; LDL: low-density lipoprotein; HDL: high-density lipoprotein.
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A
B Fig. 2. Residual effects (expressed as percentage) of brachial artery flow mediated dilation (FMD), pulse wave velocity (PWV) and ß-stiffness index 5, 7 and 10 months after lowdose fluvastatin/valsartan therapy discontinuation. Values are expressed as means ± SEM.
C
D
Fig. 1. Absolute values of A) brachial artery flow mediated dilation (FMD), B) pulse wave velocity (PWV), C) ß-stiffness index and D) high sensitivity C-reactive protein (hs-CRP) values in the placebo and the intervention group at the beginning (white bars) and at the end of the study (grey bars). Values are expressed as means ± SEM. * P b 0.05, ** P b 0.01 and *** P b 0.001 refer to the comparison between intervention and placebo group after 30 days of intervention.
combination of fluvastatin/valsartan produced a significant improvement of vascular functions (FMD, PWV and β stiffness). In other words, the intervention resulted in restoration of the slightly impaired endothelial function to normal levels, whereas arterial stiffness variables improved to values expected to be present in approximately 10–15 years younger individuals. Importantly, the positive effects of intervention were still present after withdrawal of drug therapy, being detectable even after approximately 7 months to a substantial degree, though of course, lower than after 30 days of intervention. In the present study vascular function was the target for the intervention; therefore drugs (fluvastatin and valsartan) with well-documented beneficial pleiotropic effects on vascular function were chosen [8–10]. Numerous previous studies have shown that the combination of a statin and an ARB i.e. fluvastatin and valsartan, in therapeutic doses improves vascular function [15,20,21]. Both additive [13] and synergistic [14,15] effects were attributed to a combination of fluvastatin and valsartan. The novelty in regard to fluvastatin and valsartan administration in the study presented was the use of very low, subtherapeutic doses of the drug combination (fluvastatin 10 mg, valsartan 20 mg). Namely, we assumed that low-doses of these drugs would be sufficient and efficacious in improving the initial, slight deterioration of arterial function already present in middle-aged, apparently healthy males. Whether such or any other intervention would be efficient in long-term improvement of vascular function in an apparently healthy middle-aged population has to date not been the focus of any research. As mentioned above, we assumed that in healthy individuals a low-dose combination (15–25% of the recommended therapeutic doses) could achieve a significant improvement in arterial functions. Indeed, the improvement of endothelial function and arterial stiffness was observed in every single individual of the intervention group in our study, thus suggesting that the low-dose combination of fluvastatin/valsartan could in fact alleviate arterial ageing. Arterial ageing reflects the general age-related decline of biological function that is accelerated by traditional cardiovascular risk factors and alleviated by interventions aimed at counteracting them [1]. Several mechanisms including senescence of the cardiovascular tissues at the cellular level and systemic derangements such as oxidative stress and chronic low-grade inflammation have been proposed as precipitators of age-related vascular function deterioration [5]. The very beneficial effects of a low-dose combination fluvastatin/valsartan obtained are likely the consequence of various mechanisms. Fluvastatin and valsartan have similar pleiotropic effects, which are amplified in the presence of both drugs [9,10,22]. The primary mechanism underlying the observed beneficial effects could be an increase in the bioavailability of nitric oxide, leading to improved endothelium-dependent vasodilation and consequently improved endothelial function [23]. We found a substantial improvement
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of FMD during intervention. It is somewhat surprising, but very important, that at the beginning of the study 80% of individuals already had importantly impaired endothelial function according to their measured FMD. The decrease of age-related high arterial oxidative stress and/or inflammation could be the other possible mechanism underlying the success of our intervention. The proposed mechanism could originate in the beneficial effect of statins in increasing NO synthesis and also the synergistic effect of statins and sartans on decreasing angiotensin II expression. Other non-identified or unknown mechanisms could also be involved. In the present study we unexpectedly found a significant decrease in hs-CRP during treatment with the low-dose fluvastatin/ valsartan combination. This finding could at least partially explain the mechanism(s) underlying the success of the described intervention. The changes in hs-CRP levels did not correlate with changes in FMD, PWV or ß stiffness. Considering the fact that hs-CRP is a nonspecific variable affected by numerous factors, the absence of correlations is not unexpected. In view of our results and our tested population, the results of the huge, very important JUPITER trial are very relevant. In the JUPITER trial those participants who were basically not considered candidates for statin therapy, nevertheless significantly benefited from it. Thus treatment with rosuvastatin (20 mg/day) resulted in a decrease of cardiovascular events and total mortality in asymptomatic patients with normal values of cholesterol, but increased levels of high-sensitivity Creactive protein [24]. At this stage of research we did not measure other potential mechanisms involved, such as markers of the oxidative stress burden: this represents a limitation of the present study. Clearly further studies with the aim of clarifying the underlying mechanisms are needed. Another very important observation that could have clinical repercussions, is the presence of a prolonged protective effect after discontinuation of intervention, i.e. withdrawal of drugs. The improvement of vascular effects was still detectable at significant levels even after approximately 7 months. This prolonged effect could be due to the increased gene expression responsible for the beneficial vascular effects induced by the intervention. This issue remains to be further explored in the future. Based on this important finding, the proposed approach for delaying age-associated arterial system changes would seem to be the most appropriate in the intermittent, and not continuous, mode. Of course, the intermittent approach has several advantages over the continuous one. We performed similar randomised, placebo-controlled clinical studies with fluvastatin or valsartan separately before the present study [16,17]. Both drugs achieved a significant improvement of vascular function in apparently healthy middle-aged males, but the level and duration of the recorded effects were much lower and shorter than in the case of their combination. Even though a head-to-head comparison was not performed at this stage, the combination of fluvastatin/valsartan appears to be much more effective. This assumption can be interpreted as a result of the previously described potential synergistic effects of their combination. At present a four arms study is underway to definitively answer this question. Treatment with a low-dose combination of fluvastatin/valsartan did not produce any changes in lipids and/or the blood pressure profile. Evidently, the concentrations of drugs were too low to achieve their primary therapeutic effect. Therefore, this regimen probably has an advantageous safety profile. In fact, participants in our study did not report any side-effects. The short-term treatment, the low-dose of drugs and good safety profile should probably result in a high compliance. In our view, the most practical and effective way of application of this approach would be repetition of short-term (1 month) treatment every 6–9 months, since long-term sustained effects were achieved by this intervention. In summary, we conclude that short-term intervention by a lowdose combination fluvastatin/valsartan produces significant and longlasting improvement of age-related impairment of the vascular function in middle-aged, apparently healthy males. The results and conclusions
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of our study should obviously be confirmed in a large clinical trial, and then their external validity and generalizability could and should be established in clinical practice. The described intervention suggests a possible new approach for early prevention of arterial ageing and atherosclerosis. 5. Learning points The aim of the present study was to test to what extent a low-dose combination of fluvastatin/valsartan could improve age-related impairment of endothelial function and arterial stiffness in apparently healthy, middle-aged subjects, and how long the effect would last after therapy discontinuation. The main results were: • Intervention with a low-dose combination of fluvastatin/valsartan produced a significant improvement of vascular functions (FMD, PWV and β stiffness). • The intervention resulted in restoration of the slightly impaired endothelial function to normal levels, whereas arterial stiffness variables improved to values expected to be present in approximately 10–15 years younger individuals. • The beneficial vascular effects of intervention were still present after withdrawal of therapy, being present even after approximately 7 months to a substantial degree. Conflicts of interest The authors declare that they have no conflict of interest. Acknowledgements The authors would like to express their gratitude to Sara Habjan, M.D. for her help in recruiting the volunteers for the study. References [1] Nilsson PM, Boutouyrie P, Laurent S. Vascular aging: a tale of EVA and ADAM in cardiovascular risk assessment and prevention. Hypertension 2009;54:3–10. [2] Pepe S, Lakatta EG. Aging hearts and vessels: masters of adaptation and survival. Cardiovasc Res 2005;66:190–3. [3] Carerj S, Nipote C, Zimbalatti C, Zito C, Sutera Sardo L, Dattilo G, et al. Normal vascular aging evaluated by a new tool: e-tracking. Eur J Echocardiogr 2006:49 [suppl: S]. [4] Lind L. Impact of ageing on the measurement of endothelium-dependent vasodilation. Pharmacol Rep 2006;58(Suppl):41–6. [5] Hadi HA, Carr CS, Al Suwaidi J. Endothelial dysfunction: cardiovascular risk factors, therapy, and outcome. Vasc Health Risk Manag 2005;1:183–98. [6] Wykretowicz A, Gerstenberger P, Guzik P, Milewska A, Krauze T, Adamska K, et al. Arterial stiffness in relation to subclinical atherosclerosis. Eur J Clin Invest 2009;39: 11–6. [7] Laurent S, Cockcroft J, Van Bortel L, Boutouyrie P, Giannattasio C, Hayoz D, et al. Expert consensus document on arterial stiffness: methodological issues and clinical applications. Eur Heart J 2006;27:2588–605. [8] Tomiyama H, Yamashina A. Non-invasive vascular function tests: their pathophysiological background and clinical application. Circ J 2010;74:24–33. [9] Blum A, Shamburek R. The pleiotropic effects of statins on endothelial function, vascular inflammation, immunomodulation and thrombogenesis. Atherosclerosis 2009;203:325–30. [10] Jankowski P, Safar ME, Benetos A. Pleiotropic effects of drugs inhibiting the renin– angiotensin–aldosterone system. Curr Pharm Des 2009;15:571–84. [11] Sugiyama M, Ohashi M, Takase H, Sato K, Ueda R, Dohi Y. Effects of atorvastatin on inflammation and oxidative stress. Heart Vessels 2005;20:133–6. [12] Castilla Guerra L, del Carmen Fernandez Moreno M, Lopez Chozas JM, Jimenez Hernandez MD. Statins in stroke prevention: what an internist should know. Eur J Intern Med 2008;19:8–14. [13] Hussein O, Shneider J, Rosenblat M, Aviram M. Valsartan therapy has additive anti-oxidative effect to that of fluvastatin therapy against low-density lipoprotein oxidation: studies in hypercholesterolemic and hypertensive patients. J Cardiovasc Pharmacol 2002;40:28–34. [14] Horiuchi M, Cui TX, Li Z, Li JM, Nakagami H, Iwai M. Fluvastatin enhances the inhibitory effects of a selective angiotensin II type 1 receptor blocker, valsartan, on vascular neointimal formation. Circulation 2003;107:106–12. [15] Liu L, Zhao SP, Zhou HN, Li QZ, Li JX. Effect of fluvastatin and valsartan, alone and in combination, on postprandial vascular inflammation and fibrinolytic activity in patients with essential hypertension. J Cardiovasc Pharmacol 2007;50:50–5.
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[16] Lunder M, Janic M, Habjan S, Sabovic M. Subtherapeutic, low-dose fluvastatin improves functional and morphological arterial wall properties in apparently healthy, middle-aged males a pilot study. Atherosclerosis 2011;215:446–51. [17] Lunder M, Janic M, Sabovic M. Reduction of age-associated arterial wall changes by lowdose valsartan. Eur J Cardiovasc Prev Rehabil 2011, doi:10.1177/1741826711423104. [18] Corretti MC, Anderson TJ, Benjamin EJ, Celermajer D, Charbonneau F, Creager MA, et al. Guidelines for the ultrasound assessment of endothelial-dependent flowmediated vasodilation of the brachial artery: a report of the International Brachial Artery Reactivity Task Force. J Am Coll Cardiol 2002;39:257–65. [19] Celermajer DS, Sorensen KE, Gooch VM, Spiegelhalter DJ, Miller OI, Sullivan ID, et al. Non-invasive detection of endothelial dysfunction in children and adults at risk of atherosclerosis. Lancet 1992;340:1111–5. [20] Koh KK, Han SH, Oh PC, Shin EK, Quon MJ. Combination therapy for treatment or prevention of atherosclerosis: focus on the lipid-RAAS interaction. Atherosclerosis 2010;209:307–13.
[21] Yoshikawa M, Nakamura K, Nagase S, Sakuragi S, Kusano KF, Matsubara H, et al. Effects of combined treatment with angiotensin II type 1 receptor blocker and statin on stent restenosis. J Cardiovasc Pharmacol 2009;53:179–86. [22] van Haelst PL, van Doormaal JJ, May JF, Gans RO, Crijns HJ, Tervaert JW. Secondary prevention with fluvastatin decreases levels of adhesion molecules, neopterin and C-reactive protein. Eur J Intern Med 2001;12:503–9. [23] Skogastierna C, Luksha L, Kublickiene K, Eliasson E, Rane A, Ekstrom L. Beneficial vasoactive endothelial effects of fluvastatin: focus on prostacyclin and nitric oxide. Heart Vessels 2011, doi:10.1007/s00380-010-0097-x. [24] Ridker PM, MacFadyen JG, Fonseca FA, Genest J, Gotto AM, Kastelein JJ, et al. Number needed to treat with rosuvastatin to prevent first cardiovascular events and death among men and women with low low-density lipoprotein cholesterol and elevated high-sensitivity C-reactive protein: justification for the use of statins in prevention: an intervention trial evaluating rosuvastatin (JUPITER). Circ Cardiovasc Qual Outcomes 2009;2:616–23.