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Hormone replacement therapy, C-reactive protein, and fibrinogen in healthy postmenopausal women
Maturitas 46 (2003) 245 /253 www.elsevier.com/locate/maturitas
Hormone replacement therapy, C-reactive protein, and fibrinogen in healthy postmenopausal women Mehmet Yilmazer a,*, Veysel Fenkci a, Semin Fenkci b, Murat Sonmezer c, Orhan Aktepe d, Mustafa Altindis d, Gulay Kurtay c a
Department of Obstetrics and Gynecology, Faculty of Medicine, Afyon Kocatepe University, Afyon, Turkey b Department of Internal Medicine, Faculty of Medicine, Afyon Kocatepe University, Afyon Turkey c Department of Obstetrics and Gynecology, Faculty of Medicine, Ankara University, Ankara, Turkey d Department of Microbiology, Faculty of Medicine, Afyon Kocatepe University, Afyon, Turkey Received 29 January 2002; received in revised form 28 January 2003; accepted 11 February 2003
Abstract Objective: To investigate short-term and long-term effects of combined hormone replacement therapy (HRT) on Creactive protein (CRP) and fibrinogen plasma concentrations in healthy postmenopausal women. Methods: In this cross-sectional study 241 healthy postmenopausal women were enrolled. A total of 81 women were receiving the following treatments for 3 months; transdermal 17b-estradiol (17b-E2)/medroxyprogesterone acetate (MPA) (n /21), oral 17b-E2/norethisterone acetate (NETA) (n /27), and conjugated equine estrogens (CEE)/MPA (n /33). The same combined therapies were implemented in another 58 women for 12 months; transdermal 17b-E2/MPA (n /10), oral 17b-E2/NETA (n /16), and CEE/MPA (n /32). Control group included 102 healthy postmenopausal women not receiving HRT. The effect of the type and the duration of HRT regimens on plasma levels of CRP, fibrinogen and lipids were investigated. Results: Median CRP concentrations were significantly higher in women receiving oral 17bE2/NETA (P /0.037) and CEE/MPA (P /0.0001) for 3 months than in women taking the same types of HRT for 12 months and of those were not on HRT. Median CRP levels were similar in women taking transdermal 17b-E2/ MPA for 3 and 12 months, compared with controls. Fibrinogen levels were not different between nonusers and any group of HRT users. Conclusions: These elevated levels of CRP, which appears very recently as a crucial marker for cardiovascular disease, may be responsible for the early increased cardiovascular risk after starting oral combined HRT. But this increased risk in the early period seems to decrease with long-term use. Transdermal 17b-E2/MPA had insignificant effect on CRP both in short-term or in long-term use. # 2003 Elsevier Ireland Ltd. All rights reserved. Keywords: C-reactive protein; Fibrinogen; Hormone replacement therapy; Inflammation
1. Introduction * Corresponding author. Present address: Tip Fakultesi Hastanesi, Kocatepe Universitesi, Kadin Hast. ve Dog˘um Anabilim Dali, 03200 Afyon, Turkey. Tel.: /90-272-2171753x112; fax: /90-272-217-2029. E-mail address: [email protected] (M. Yilmazer).
It has long been known that the incidence of cardiovascular disease increases after menopause [1]. On the basis of epidemiological studies,
0378-5122/03/$ - see front matter # 2003 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/S0378-5122(03)00217-2
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hormone replacement therapy (HRT) has been alleged to reduce cardiovascular risk [2]. In contrast, a pooled analysis of short-term clinical trials showed adverse effects, with a relative risk of 1.39 of cardiovascular events [3]. In the Heart and Estrogen/progestin Replacement study (HERS), HRT regimens used appeared to increase the risk of new cardiovascular events in the first year (relative risk 1.5 95% confidence interval 1.0 / 2.3), and tended to decrease the risk in subsequent years [4]. C-reactive protein (CRP) is hepatically-derived acute phase reactant protein which is associated with clinical inflammation [5]. Elevated levels of CRP, predict future myocardial infarction in patients with unstable angina [6], the risk of first myocardial infarction and ischemic stroke in healthy men and women [7 /9]. In a report from Women Health Study (WHS), women with a CRP concentration in the highest quartile had a 7-fold increased risk of subsequent myocardial infarction and stroke compared with women with CRP levels in the lowest quartile [7]. In the Postmenopausal Estrogen/Progestin Intervention (PEPI) study, assignment to HRT was associated with an increase in CRP levels, compared with women on placebo [10]. Since increased CRP levels appeared to be an independent risk factor to predict future cardiovascular events, higher CRP levels may be associated with cardiovascular disease observed in patients receiving HRT. Fibrinogen is an acute phase reactant protein and reflects the inflammatory state of the vascular wall. Increased plasma fibrinogen concentration has emerged as an independent risk factor for ischemic heart disease [11]. Several studies demonstrated lower fibrinogen levels in women using HRT [12], but contradictory reports also exist which stated no change [13], or even an increase in the fibrinogen levels during short-term follow-up after the initiation of a combined HRT [14]. In this cross-sectional study, we investigated short-term (3 months) and long-term (12 months) effects of different types of estrogen/progestin replacement therapy that were administered either orally or transdermally on plasma CRP and fibrinogen concentrations in healthy postmenopausal women.
2. Materials and methods Two hundred and forty one healthy postmenopausal women, aged 40 /62 years, were evaluated in this cross-sectional study. All of the participating postmenopausal women were normotensive (B/150/90 mmHg) and non-hysterectomized who had been amenorrheic for at least 12 months before entering the study. An informed consent was obtained from all of the participants. Patients with a prior or current history of systemic diseases such as diabetes mellitus, cardiovascular disease, chronic inflammatory disease, rheumatismal disease or malignant disease, and who had hematological, metabolic, hepatic and renal impairments were excluded. Women with possible contraindications to hormone use, plasma triglycerides and total cholesterol levels /2.25 and /6.50 mmol/l, respectively, and a body mass index (BMI) /35 kg/m2, and operated within past 6 months or smoked cigarettes within past 1 year were also excluded. The participating 241 women were divided in to the following three groups: Group 1 (Control group): Included 102 healthy postmenopausal women who were not receiving HRT and were amenorrheic for at least 12 months. Postmenopausal status was confirmed by serum follicle stimulating hormone (FSH) / 30 mIU/ml and estradiol B/30 pg/ml. Women who had a history of previous HRT use, or used any hormone therapy within past 6 months were not involved in the control group. Group 2: Involved 81 healthy postmenopausal women who were receiving one of the following HRT regimens for 3 months: transdermal 17bestradiol (17b-E2) 50 mg/day plus continuous oral medroxyprogesterone acetate (MPA) 2.5 mg/day (n /21), or oral 17b-E2 2 mg/day plus continuous norethisterone acetate (NETA) 1 mg/day (n /27), or oral CEE 0.625 mg/day plus continuous MPA 2.5 mg/day (n /33). Group 3: Included 58 healthy postmenopausal women who were using one of the following HRT regimens for 12 months: transdermal 17bE2 50 mg/day plus continuous oral MPA 2.5 mg/ day (n /10), or oral 17b-E2 2 mg/day plus
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continuous NETA 1 mg/day (n /16), or oral CEE 0.625 mg/day plus continuous MPA 2.5 mg/day (n /32). Venous blood samples were drawn in the morning after at least 10 h of fasting. Serum total cholesterol (T-Chol.), triglyceride (TG), high density lipoprotein cholesterol (HDL), very low density lipoprotein cholesterol (VLDL) levels were determined in Hitachi 911 automated analyzer by using commercial kits supplied from Roche Diagnostics. Low-density lipoprotein cholesterol (LDL) levels were calculated by using Friedewald’s formula. Clottable fibrinogen was quantified by using liquid thrombin reagent (DiaMed AG, Switzerland). Serum CRP levels were measured by turbidimetric assay. Turbidimetry is based on the measurement of the turbidity occurred immunoprecipitation of CRP in sera and the specific reagent including latex particles coated with antihuman CRP antibodies (Biosystems, USA). The intensity of the reaction is detected by an optical system comparing with the calibrators that gives a quantitative result. Sensitivity was 0.11 mg/l, and intra and interassay coefficients of variation were 5.0 and 6.5%, respectively. In this study, an automatic analyzer (SPACE, Schiparelli Biosystem Inc., USA) was used for detection of CRP levels in patient’s serum. 2.1. Statistical analysis Data was collected in a WINDOWS-based relational database (MICROSOFT EXCELL 2000) and analyzed with the Statistical Package for the Social Science (SPSS, version 11.0) for WINDOWS 98 (Microsoft Corp.). Values are given as mean9/ standard deviation (S.D.), or as mean9/S.D. and range, or as median and range. To compare women using the same HRT regimen for different duration with control group, one-way ANOVA or Kruskal/Wallis test was used. In addition, oneway ANOVA or Kruskal /Wallis test was also used to compare women receiving different types of HRT for the same duration. Data from the three different HRT treatment groups were compared with the control group data using Mann/ Whitney U -test or Student’s unpaired t-test.
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Because the distribution of CRP was skewed, logarithmic transformation was used. Correlations between variables were calculated with Pearson’s correlation coefficient. There was a significant difference between the groups in duration of amenorrhea (Tables 1 and 2); therefore, we analyzed between group differences with duration of amenorrhea as a second constant covariate. Statistical significance was defined as P B/0.05.
3. Results The participants were matched with respect to duration and the type of HRT (Tables 1 and 2). 3.1. Clinical characteristics Women receiving CEE/MPA for 3 months had a shorter mean duration of amenorrhea, compared with women not on HRT, and to those receiving transdermal 17b-E2/MPA, and oral 17b-E2/ NETA for 3 months (P B/0.05). In addition, mean duration of amenorrhea in women receiving transdermal 17b-E2/MPA for 12 months was longer than that of control group, of women taking oral 17b-E2/NETA, and of women taking oral CEE/MPA for 12 months (P B/0.05). Mean plasma FSH concentrations in women not on HRT were higher than those in women receiving any type of HRT either for 3 or 12 months (P B/0.05). Women receiving HRT for either 3 or 12 months had higher estradiol levels, compared with control group. Plasma FSH levels were both similar among all women receiving HRT for 3 months, but serum estradiol levels was higher in oral CEE/MPA group, than in transdermal 17b-E2/MPA and in oral 17b-E2/ NETA groups (P B/0.05). FSH and estradiol levels were all similar among women receiving any type of HRT for 12 months. All treatment groups and control group were similar with respect to age and BMI (Tables 1 and 2). 3.2. C-reactive protein CRP concentrations were significantly higher in women receiving oral 17b-E2/NETA (P /0.017)
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Table 1 Characteristics of women in control group and women receiving three different types of HRT for 3 months
Age (years) Duration of amenorhea (years) FSH (mIU/ml) Estradiol (pg/ml) Fibrinogen (mg/dl)e CRP (mg/l)e T-Chol. (mmol/l) TG (mmol/l) HDL (mmol/l) LDL (mmol/l) VLDL (mmol/l) BMI (kg/m2)
Control (n / 102)
Transdermal 17b-E2/MPA (n /21)
Oral 17b-E2/NETA (n /27)
Oral CEE/MPA (n / 33)
49.39/5.1 (40 / 62) 4.49/4.8 (1 /25)
49.59/4.6 (40 /60)
48.79/4.5 (40 /57)
47.59/4.8 (40 /59)
3.99/4.7 (1 /22)
3.69/2.8 (1 /10)
1.99/1.9 (1 /8)d
65.59/23.8 22.09/19.9 309 (180 /414) 0.48 (0.00 /1.23) 5.559/0.89 1.529/0.66 1.429/0.29 3.819/0.79 0.329/0.15 27.59/2.9
50.59/25.8a 34.29/27.6 300 (242 /388) 0.60 (0.00 /1.11) 5.249/0.90 1.589/0.60 1.329/0.38 3.519/0.80a 0.349/0.18 26.99/2.8
38.89/28.2b 54.49/36.0b 312 (175 /423) 0.90 (0.30 /1.54)b 5.159/0.81 1.569/0.56 1.359/0.31 3.499/0.64b 0.319/0.11 27.29/3.1
32.89/25.6c 95.19/44.9c 289 (220 /420) 0.78 (0.30 /2.12)c 5.249/0.83 1.689/0.63 1.419/0.34 3.499/0.73c 0.349/0.14 27.19/3.3
Values are given as mean9/S.D. or mean9/S.D. and range. FSH, follicle stimulating hormone; CRP, C-reactive protein; T-Chol., total cholesterol; TG, triglyceride; HDL, high density lipoprotein cholesterol; LDL, low density lipoprotein cholesterol; VLDL, very low density lipoprotein cholesterol; BMI, body mass index; MPA, medroxyprogesterone acetate; NETA, norethisterone acetate; E2, estradiol. Note: Statistics were performed on log-transformed data for CRP values. a Defines P B/0.05 value for comparison of transdermal 17b-E2/MPA group with control group. b Defines P B/0.05 value for comparison of oral 17b-E2/NETA group with control group. c Defines P B/0.05 value for comparison of oral CEE/MPA group with control group. d Defines P B/0.05 value for comparison of oral CEE/MPA group with control, transdermal 17b-E2/MPA and oral 17b-E2/ NETA. e Values are given as median and range.
and in CEE/MPA (P /0.0001) for 3 months than in women not on HRT. Median CRP level was slightly higher in women taking transdermal 17b-E2/MPA for 3 months compared with controls, but this difference was not statically significant (P /0.05, Table 1). When treatment groups receiving HRT for 12 months were compared with control group according to median plasma CRP levels, no significant differences were detected (Table 2). When the data were reanalyzed in relation to duration of HRT use, women receiving oral 17bE2/NETA for 3 months had a significantly higher CRP concentration compared with those taking oral 17b-E2/NETA for 12 months (P /0.035) (Fig. 1). In addition, women using CEE/MPA for 3 months had a significantly higher CRP level than that of women taking CEE/MPA for 12 months (P /0.045) (Fig. 2). CRP concentrations were almost similar among women receiving
transdermal 17b-E2/MPA irrespective of duration of use (Fig. 3). There were no significant correlations between CRP; and age, duration of menopause, plasma concentrations of FSH, estradiol, T-Chol., TG, HDL, LDL and VLDL. 3.3. Fibrinogen There were no statistical differences in median fibrinogen distributions between nonusers and any group of HRT users. The type and the duration of HRT use caused no significant changes in median plasma fibrinogen concentrations. 3.4. Lipids Serum LDL levels were more favorable in HRT users for 3 months. Mean LDL concentrations in every treatment groups receiving HRT for 3 months were lower than in women who were not
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Table 2 Characteristics of women in control group and women receiving three different types of HRT for 12 months
Age (years) Duration of amenorhea (years) FSH (mIU/ml) Estradiol (pg/ml) Fibrinogen (mg/dl)e CRP (mg/l)e T-Chol. (mmol/l) TG (mmol/l) HDL (mmol/l) LDL (mmol/l) VLDL (mmol/l) BMI (kg/m2)
Control (n / 102)
Transdermal 17b-E2/MPA (n /10)
Oral 17b-E2/NETA (n /16)
Oral CEE/MPA (n / 32)
49.39/5.1 (40 / 62) 4.49/4.8 (1 /25)
52.79/5.5 (45 /62)
48.99/5.6 (40 /60)
48.69/4.0 (40 /62)
8.09/5.9 (2 /20)d
4.99/4.3 (1 /14)
4.09/3.5 (1 /15)
65.59/23.8 22.09/19.9 309 (180 /414) 0.48 (0.00 /1.23) 5.559/0.89 1.529/0.66 1.429/0.29 3.819/0.79 0.329/0.15 27.59/2.9
37.39/25.6a 49.29/28.1a 284.5 (215 /355) 0.59 (0.00 /1.28) 5.519/1.22 1.459/0.52 1.669/0.31a 3.559/1.22 0.299/0.10 26.89/3.1
43.89/26.0b 49.39/26.1b 304 (213 /464) 0.53 (0.00 /0.90) 5.189/0.96 1.559/0.61 1.529/0.34 3.349/0.95 0.319/0.12 27.79/3.4
50.89/25.9c 43.59/23.1c 301.5 (224 /434) 0.62 (0.00 /1.23) 5.379/0.80 1.699/0.57 1.459/0.38 3.559/0.85 0.379/0.17 27.49/3.6
Values are given as mean9/S.D. or mean9/S.D. and range. FSH, follicle stimulating hormone; CRP, C-reactive protein; T-Chol., total cholesterol; TG, triglyceride; HDL, high density lipoprotein cholesterol; LDL, low density lipoprotein cholesterol; VLDL, very low density lipoprotein cholesterol; BMI, body mass index; MPA, medroxyprogesterone acetate; NETA, norethisterone acetate; E2, estradiol. Note: Statistics were performed on log-transformed data for CRP values. a Defines P B/0.05 value for comparison of transdermal 17b-E2/MPA group with control group. b Defines P B/0.05 value for comparison of oral 17b-E2/NETA group with control group. c Defines P B/0.05 value for comparison of oral CEE/MPA group with control group. d Defines P B/0.05 value for comparison of transdermal 17b-E2/MPA group with control, oral 17b-E2/NETA and oral CEE/ MPA. e Values are given as median and range.
Fig. 1. Median concentrations of CRP in women not on HRT, receiving oral 17b-E2/NETA for 3 or 12 months. * P /0.037, differences between women receiving 17b-E2/NETA for 3 months, and women receiving 17b-E2/NETA for 12 months, and women not on HRT (Kruskal /Wallis test). CRP, Creactive protein; NETA, norethisterone acetate.
Fig. 2. Median concentrations of CRP in women not on HRT, receiving oral CEE/MPA for 3 or 12 months. * P /0.0001, differences between women receiving oral CEE/MPA for 3 months, and women receiving oral CEE/MPA for 12 months, and women not on HRT (one-way ANOVA). CRP, C-reactive protein; CEE, conjugated equine estrogen; MPA, medroxyprogesterone acetate.
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Fig. 3. Median concentrations of CRP in women not on HRT, receiving transdermal 17b-E2/MPA for 3 or12 months. P / 0.05, differences between groups (Kruskal /Wallis test). CRP, C-reactive protein; MPA, medroxyprogesterone acetate.
taking any therapy (P B/0.05). Mean T-Chol. levels were lower in women taking HRT for 3 or 12 months compared with women on no therapy. But there were no statically significant differences in T-Chol. levels between non-user and HRT user groups. HDL level was higher in women receiving transdermal 17b-E2/MPA for 12 months compared with control group (P B/0.05), whereas other groups of HRT users were similar to control patients. Plasma levels of TG, HDL, and VLDL in patients receiving HRT for 3 months were also similar to those of control group. Moreover, plasma T-Chol., TG, LDL, VLDL levels in treatment groups for 12 months and control group were similar (Tables 1 and 2).
4. Discussion This study has revealed that each HRT regimen induces different changes in plasma CRP concentrations considered to predict future cardiovascular disease and those changes are dependent on the particular preparation, the duration of use and its route of administration. Recently published data indicate that CRP may be an independent risk marker for cardiovascular disease [9,15/17]. CRP concentrations are elevated
after myocardial infarction and this seems to be a predictor of future cardiovascular events [18,19]. There is increasing evidence that HRT increases plasma concentrations of CRP [10,20 /27]. The association between the increased CRP concentration and the administration of HRT has not been clarified yet. But as a result of oral HRT use, hepatic synthesis of this protein increases and an elevation in the level of CRP is seen [21,24]. It is presumed that an increase in CRP concentration is resulted in heightened plaque instability and a tendency to thrombosis and consequently, there is an increase in the risk of cardiovascular diseases [10,22]. Previous studies have showed that during the early period of treatment there was a rapid increase in CRP concentrations [21,28]. The most significant elevation of CRP values was seen in the first year of the treatment and this tended to sustain in subsequent years in the PEPI study [10]. In general, the short-term (1 /3 months) [21,24,29,30] and long-term (3 /5 years) [22,25] impacts of HRT on CRP were investigated in different studies performed thus far. Nevertheless, both short-term and long-term effects of HRT on CRP together have not been investigated in the same study yet. In this study, we investigated short-term (3 months) and long-term (12 months) effects of three different combined estrogen/progestin replacement therapy regimens that were administered either orally or transdermally on CRP plasma concentrations in healthy postmenopausal women. In the present study; the higher CRP levels found in 3 months combined oral HRT regimens indicated that oral route may cause a significant increase in CRP concentrations in early period of HRT. In some previous studies it was reported that postmenopausal women receiving long-term HRT had higher CRP levels [10,22,25]. However, in our study lower CRP levels were observed in women using long-term oral HRT compared with those using short-term. At present it seems that further studies are required to make a definite conclusion on this subject. Oral CEE alone or combined with progesterone was usually investigated in previous studies. In Europe, however, CEE are used to a lesser extend
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and increasing numbers of women are being prescribed either transdermal 17b-E2 or oral 17bE2. There were a few studies in literature about the effect of oral 17b-E2, especially transdermal estrogens, on CRP concentrations. In a small study by Vehkavaara et al., the concentration of CRP in transdermal estradiol users was not significantly higher than placebo group [29]. Two different investigators recently confirmed Vehkavaara’s results [25,31]. We found that short-term (3 months) and long-term (12 months) use of transdermal 17bE2/MPA had similar effects on CRP, those were not different from the control group. These finding were consistent with previous ones. The fact that difference observed between transdermal route, which had no significant effect on CRP irrespective of treatment duration, and oral route, which had a significant higher CRP level in short-term using may be explained by the hepatic first pass effect of oral estrogens [21,30,31]. All women enrolled in our study had intact uterus, in order to protect endometrium combined HRT was used. In most of the previous studies, it was reported that there was no any significant difference between women who used unopposed estrogen and combined estrogen/progestin therapy on CRP concentration, that is why it has been suggested that addition of progestin to treatment does not affect CRP concentration [10,20,21,25]. Therefore, we did not evaluate women who used unopposed estrogen. Fibrinogen is an acute phase reactant protein and a marker of risk of cardiovascular events and severity of atherosclerosis. It has been estimated that increased plasma fibrinogen level reflects the inflammatory state of the vascular wall. This inflammation has even been suggested to be the main mechanism of atherosclerosis [32]. Although some of the studies reported a decrease in fibrinogen levels with HRT use [12,33,34], some studies reported no change [13,21]. We did not detect any change in the median fibrinogen level during short and long-term treatment. In addition, the type and duration of HRT made no significant changes in plasma fibrinogen concentrations. Types of HRT and route of administration can affect serum lipids. Several randomized clinical trials have shown that oral administration of HRT
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reduces serum T-Chol. and LDL levels, and increase HDL levels in postmenopausal women [4,33,35,36]. In our study, patients on short-term HRT, irrespective of the type, had significantly lower LDL levels than women not on HRT. Moreover, in our study, serum T-Chol. levels were detected lower, but not statically significant, in all treatment groups. In previous studies included PEPI trial, serum HDL levels in women receiving combined estrogen replacement therapy were detected higher [3,33,35,36] but we did not observe any significant difference in women using oral combined estrogen replacement therapy with respect to HDL levels compared with women not on HRT. Additionally serum TG and VLDL levels were similar in all patients irrespective of the type or duration of treatment. Our study has some limitations; first it is a crosssectional study, second as most of the other researches on HRT, study groups include only healthy women who have a low risk for cardiovascular disease which may influence results [37], and third, all participants in our study received combined HRT which may preclude drawing conclusion regarding the effects of estrogen alone. The differential effect of various HRT regimens on some specific cardiovascular disease risk markers observed in this study had potentially important clinical implications. The effects of HRT on CRP and lipids depend on the preparation, or its route, or duration of administration. Our study suggests that, although short-term (3 months) oral combined HRT regimens have beneficial effects on serum lipids, there was a relationship between oral combined regimens and higher CRP concentrations. The increased risk of cardiovascular disease observed shortly after the onset of therapy in HERS in which high risk patients were given CEE combined with MPA [4] might be explained by this result mentioned above. We can suggest, based on the findings from our study that, the changes induced by some types of oral HRT regimens in short-term could further increase the risk of cardiovascular disease in women already at risk. For such women transdermal estrogen replacement therapy regimens might be a reasonable option.
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Even we may suggest that oral HRT increases the risk of cardiovascular events during short-term use, in order to make a clear-cut conclusion regarding the effect of transdermal or oral HRT on the risk of cardiovascular events during shortterm or long-term use further large controlled studies are required.
[12]
[13]
[14]
References [1] Wenger NK, Speroff L, Packard B. Cardiovascular health and disease in women. New Engl J Med 1993;329:247 /56. [2] Barrett-Connor E, Wenger NK, Grady D, et al. Hormone and nonhormone therapy for the maintenance of postmenopausal health: the need for randomized controlled trials of estrogen and raloxifene. J Women Health 1998;7:839 /47. [3] Hemminki E, McPherson K. Impact of postmenopausal hormone therapy on cardiovascular events and cancer: pooled data from clinical trials. Br J Med 1997;315:149 / 53. [4] Heart and estrogen/progestin replacement study (HERS) research group, Hulley S, Grady D, Bush T, et al. Randomized trial of estrogen plus progestin for secondary prevention of coronary heart disease in postmenopausal women. J Am Med Assoc 1998;280:605 /13. [5] Richards CD, Gauldie J. Role of cytokines in acute-phase response. In: Aggarwal BB, Puri RK, editors. Human cytokines: their role in disease and therapy. Cambridge, MA: Blackwell Science, 1995:253 /69. [6] Toss H, Lindahl B, Siegbahn A, Wallentin L. Prognostic influence of increased fibrinogen and C-reactive protein levels in unstable coronary artery disease. FRISC Study Group. Fragmin during instability in coronary artery disease. Circulation 1997;96:4204 /10. [7] Ridker PM, Buring JE, Shih J, Matias M, Hennekens CH. Prospective study of C-reactive protein and the risk of future cardiovascular events among apparently healthy women. Circulation 1998;98:731 /3. [8] Ridker PM, Glynn RJ, Hennekens CH. C-reactive protein adds to the predictive value of total, and HDL cholesterol in determining risk of first myocardial infarction. Circulation 1998;97:2007 /11. [9] Tracy RP, Lemaitre RN, Psaty BM, et al. Relationship of C-reactive protein to risk of cardiovascular disease in the elderly: results from the Cardiovascular Health Study and the Rural Health Promotion Project. Arterioscler Thromb Vasc Biol 1997;17:1121 /7. [10] Cushman M, Legault C, Barrett-Connor E, et al. Effect of postmenopausal hormones on inflammation-sensitive proteins: the postmenopausal estrogen/progestin interventions (PEPI) study. Circulation 1999;100:717 /22. [11] de Maat MP, Pietersma A, Kofflard M, Suluiter W, Kluft C. Association of plasma fibrinogen levels with coronary
[15]
[16] [17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
artery disease, smoking and inflammatory markers. Atherosclerosis 1996;121:185 /91. Fro¨hlich M, Schunkert H, Hense HW, et al. Effects of hormone replacement therapies on fibrinogen and plasma viscosity in postmenopausal women. Br J Haematol 1998;100:577 /81. Gordon EM, Williams SR, Frenchek B, Mazur CA, Speroff L. Dose-dependent effects of postmenopausal oestrogen and progestin on antithrombin III and factor XII. J Lab Clin Med 1988;111:52 /6. Boschetti C, Cortellaro M, Nenicioni T, Bertolli V, Volpe DA, Zanussi C. Short-and long-term effects of hormone replacement therapy (transdermal estradiol vs. oral conjugated equine estrogens, combined with medroxyprogesterone acetate) on blood coagulation factors in postmenopausal women. Thromb Res 1991;62:1 /8. Ridker PM, Hennekens CH, Buring JE, Rifai N. Creactive protein and other markers of inflammation in the prediction of cardiovascular disease in women. New Engl J Med 2000;342:836 /43. Pepys MB, Berger A. The renaissance of C reactive protein. Br Med J 2001;322:4 /5. Rifai N, Ridker PM. Proposed cardiovascular risk assessment algorithm using high-sensitivity C-reactive protein and lipid screening. Clin Chem 2001;47:28 /30. Lagrand WK, Visser CA, Hermens WT, et al. C-reactive protein as acardiovascular risk factor: more than epiphenomenon. Circulation 1999;100:96 /102. Strandberg TE, Tilvis RS. C-reactive protein, cardiovascular risk factors and mortality in a prospective study in the elderly. Arterioscler Thromb Vasc Biol 2000;20:1057 / 60. Ridker PM, Hennekens CH, Rifai N, Buring JE, Manson JE. Hormone replacement therapy and increased plasma concentration of C-reactive protein. Circulation 1999;100:713 /6. Van Baal WM, Kenemans P, Van der Mooren MJ, Kessel H, Emeis JJ, Stehouwer CDA. Increased C-reactive protein levels during short-term hormone replacement therapy in healthy postmenopausal women. Thromb Haemost 1999;81:925 /8. Cushman M, Meilahn EN, Psaty BM, Kuller LH, Dobs AS, Tracy RP. Hormone replacement therapy, inflammation and hemostasis in elderly women. Arterioscler Thromb Vasc Biol 1999;19:893 /9. Barinas-Mitchell E, Cushman M, Meilahn EN, Tracy RP, Kuller LH. Serum levels of C-reactive protein are associated with obesity, weight gain, and hormone replacement therapy in healthy postmenopausal women. Am J Epidemiol 2001;153:1094 /101. Luyer MDP, Khosla S, Owen WG, Miller VM. Prospective randomized study of effects of unopposed estrogen replacement therapy on markers of coagulation and inflammation in postmenopausal women. J Clin Endocrinol Metab 2001;86:3629 /34. Prelevic GM, Kwong P, Byrne DJ, Jagroop IA, Ginsburg J, Mikhalidis DP. A cross-sectional study of the effects of
M. Yilmazer et al. / Maturitas 46 (2003) 245 /253
[26]
[27]
[28]
[29]
[30]
[31]
hormone replacement therapy on the cardiovascular disease risk profile in healthy postmenopausal women. Fertil Steril 1996;77:945 /51. Yildirir A, Aybar F, Tokgo¨zog˘lu L, et al. Effects of hormone replacement therapy on plasma homocystein and C-reactive protein levels. Gynecol Obstet Invest 2002;53:54 /8. Skouby SO, Gram J, Andersen LF, Sidelmann J, Petersen KR, Jespersen J. Hormone replacement therapy: estrogen and progestin effects on plasma C-reactive protein concentrations. Am J Obstet Gynecol 2002;186:969 /77. Walsh BW, Paul S, Wild RA, et al. The effects of hormone replacement therapy and raloxifene on C-reactive protein and homocysteine in healthy postmenopausal women: a randomized, controlled trial. J Clin Endocrinol Metab 2000;85:214 /8. Vehkavaara S, Silveira A, Pietila TH, et al. Effects of oral and transdermal estrogen replacement therapy on markers of coagulation, fibrinolysis, inflammation and serum lipids and lipoproteins in postmenopausal women. Thromb Haemost 2001;85:619 /25. Herrington DM, Brosnihan KB, Pusser BE, et al. Differential effects of E and droloxifene on C-reactive protein and other markers of inflammation in healthy postmenopausal women. J Clin Endocrinol Metab 2001;86:4216 /22. Giltay EJ, Gooren LJG, Emeis JJ, Kooistra T, Stehouwer CDA. Oral ethinyl estradiol, but not transdermal 17b-
[32] [33]
[34]
[35]
[36]
[37]
253
estradiol, increases plasma C-reactive protein levels in men. Thromb Haemost 2000;84:359 /60. Ross R. The pathogenesis of atherosclerosis: a perspective for the 1990s. Nature 1993;3662:801 /6. The writing group for the PEPI trial. Effects of estrogen or estrogen/progestin regimens on heart disease risk factors in postmenopausal women: the postmenopausal estrogen/ progestin interventions (PEPI) trial. J Am Med Assoc 1995;273:199 /208. Salomaa V, Rasi V, Pekkanen J, et al. Association of hormone replacement therapy with hemostatic and other cardiovascular risk factors. The FINRISK hemostasis study. Arterioscler Thromb Vasc Biol 1995;15:1549 /55. Lobo RA, Pickar JH, Wild RA, et al. Metabolic impact of adding medroxyprogesterone acetate to conjugated estrogen therapy in postmenopausal women. Obstet Gynecol 1994;84:987 /95. Walsh BW, Schiff I, Rosner B, et al. Effects of postmenopausal estrogen replacement therapy on the concentration and metabolism of plasma lipoproteins. New Engl J Med 1991;325:1196 /204. Matthews KA, Kuller LH, Wing RR, Meillahn EN, Plantinga P. Prior use of estrogen replacement therapy, are users healthier than nonusers. Am J Epidemiol 1996;143:971 /8.
Hormone replacement therapy, C-reactive protein, and fibrinogen in healthy postmenopausal women Mehmet Yilmazer a,*, Veysel Fenkci a, Semin Fenkci b, Murat Sonmezer c, Orhan Aktepe d, Mustafa Altindis d, Gulay Kurtay c a
Department of Obstetrics and Gynecology, Faculty of Medicine, Afyon Kocatepe University, Afyon, Turkey b Department of Internal Medicine, Faculty of Medicine, Afyon Kocatepe University, Afyon Turkey c Department of Obstetrics and Gynecology, Faculty of Medicine, Ankara University, Ankara, Turkey d Department of Microbiology, Faculty of Medicine, Afyon Kocatepe University, Afyon, Turkey Received 29 January 2002; received in revised form 28 January 2003; accepted 11 February 2003
Abstract Objective: To investigate short-term and long-term effects of combined hormone replacement therapy (HRT) on Creactive protein (CRP) and fibrinogen plasma concentrations in healthy postmenopausal women. Methods: In this cross-sectional study 241 healthy postmenopausal women were enrolled. A total of 81 women were receiving the following treatments for 3 months; transdermal 17b-estradiol (17b-E2)/medroxyprogesterone acetate (MPA) (n /21), oral 17b-E2/norethisterone acetate (NETA) (n /27), and conjugated equine estrogens (CEE)/MPA (n /33). The same combined therapies were implemented in another 58 women for 12 months; transdermal 17b-E2/MPA (n /10), oral 17b-E2/NETA (n /16), and CEE/MPA (n /32). Control group included 102 healthy postmenopausal women not receiving HRT. The effect of the type and the duration of HRT regimens on plasma levels of CRP, fibrinogen and lipids were investigated. Results: Median CRP concentrations were significantly higher in women receiving oral 17bE2/NETA (P /0.037) and CEE/MPA (P /0.0001) for 3 months than in women taking the same types of HRT for 12 months and of those were not on HRT. Median CRP levels were similar in women taking transdermal 17b-E2/ MPA for 3 and 12 months, compared with controls. Fibrinogen levels were not different between nonusers and any group of HRT users. Conclusions: These elevated levels of CRP, which appears very recently as a crucial marker for cardiovascular disease, may be responsible for the early increased cardiovascular risk after starting oral combined HRT. But this increased risk in the early period seems to decrease with long-term use. Transdermal 17b-E2/MPA had insignificant effect on CRP both in short-term or in long-term use. # 2003 Elsevier Ireland Ltd. All rights reserved. Keywords: C-reactive protein; Fibrinogen; Hormone replacement therapy; Inflammation
1. Introduction * Corresponding author. Present address: Tip Fakultesi Hastanesi, Kocatepe Universitesi, Kadin Hast. ve Dog˘um Anabilim Dali, 03200 Afyon, Turkey. Tel.: /90-272-2171753x112; fax: /90-272-217-2029. E-mail address: [email protected] (M. Yilmazer).
It has long been known that the incidence of cardiovascular disease increases after menopause [1]. On the basis of epidemiological studies,
0378-5122/03/$ - see front matter # 2003 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/S0378-5122(03)00217-2
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hormone replacement therapy (HRT) has been alleged to reduce cardiovascular risk [2]. In contrast, a pooled analysis of short-term clinical trials showed adverse effects, with a relative risk of 1.39 of cardiovascular events [3]. In the Heart and Estrogen/progestin Replacement study (HERS), HRT regimens used appeared to increase the risk of new cardiovascular events in the first year (relative risk 1.5 95% confidence interval 1.0 / 2.3), and tended to decrease the risk in subsequent years [4]. C-reactive protein (CRP) is hepatically-derived acute phase reactant protein which is associated with clinical inflammation [5]. Elevated levels of CRP, predict future myocardial infarction in patients with unstable angina [6], the risk of first myocardial infarction and ischemic stroke in healthy men and women [7 /9]. In a report from Women Health Study (WHS), women with a CRP concentration in the highest quartile had a 7-fold increased risk of subsequent myocardial infarction and stroke compared with women with CRP levels in the lowest quartile [7]. In the Postmenopausal Estrogen/Progestin Intervention (PEPI) study, assignment to HRT was associated with an increase in CRP levels, compared with women on placebo [10]. Since increased CRP levels appeared to be an independent risk factor to predict future cardiovascular events, higher CRP levels may be associated with cardiovascular disease observed in patients receiving HRT. Fibrinogen is an acute phase reactant protein and reflects the inflammatory state of the vascular wall. Increased plasma fibrinogen concentration has emerged as an independent risk factor for ischemic heart disease [11]. Several studies demonstrated lower fibrinogen levels in women using HRT [12], but contradictory reports also exist which stated no change [13], or even an increase in the fibrinogen levels during short-term follow-up after the initiation of a combined HRT [14]. In this cross-sectional study, we investigated short-term (3 months) and long-term (12 months) effects of different types of estrogen/progestin replacement therapy that were administered either orally or transdermally on plasma CRP and fibrinogen concentrations in healthy postmenopausal women.
2. Materials and methods Two hundred and forty one healthy postmenopausal women, aged 40 /62 years, were evaluated in this cross-sectional study. All of the participating postmenopausal women were normotensive (B/150/90 mmHg) and non-hysterectomized who had been amenorrheic for at least 12 months before entering the study. An informed consent was obtained from all of the participants. Patients with a prior or current history of systemic diseases such as diabetes mellitus, cardiovascular disease, chronic inflammatory disease, rheumatismal disease or malignant disease, and who had hematological, metabolic, hepatic and renal impairments were excluded. Women with possible contraindications to hormone use, plasma triglycerides and total cholesterol levels /2.25 and /6.50 mmol/l, respectively, and a body mass index (BMI) /35 kg/m2, and operated within past 6 months or smoked cigarettes within past 1 year were also excluded. The participating 241 women were divided in to the following three groups: Group 1 (Control group): Included 102 healthy postmenopausal women who were not receiving HRT and were amenorrheic for at least 12 months. Postmenopausal status was confirmed by serum follicle stimulating hormone (FSH) / 30 mIU/ml and estradiol B/30 pg/ml. Women who had a history of previous HRT use, or used any hormone therapy within past 6 months were not involved in the control group. Group 2: Involved 81 healthy postmenopausal women who were receiving one of the following HRT regimens for 3 months: transdermal 17bestradiol (17b-E2) 50 mg/day plus continuous oral medroxyprogesterone acetate (MPA) 2.5 mg/day (n /21), or oral 17b-E2 2 mg/day plus continuous norethisterone acetate (NETA) 1 mg/day (n /27), or oral CEE 0.625 mg/day plus continuous MPA 2.5 mg/day (n /33). Group 3: Included 58 healthy postmenopausal women who were using one of the following HRT regimens for 12 months: transdermal 17bE2 50 mg/day plus continuous oral MPA 2.5 mg/ day (n /10), or oral 17b-E2 2 mg/day plus
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continuous NETA 1 mg/day (n /16), or oral CEE 0.625 mg/day plus continuous MPA 2.5 mg/day (n /32). Venous blood samples were drawn in the morning after at least 10 h of fasting. Serum total cholesterol (T-Chol.), triglyceride (TG), high density lipoprotein cholesterol (HDL), very low density lipoprotein cholesterol (VLDL) levels were determined in Hitachi 911 automated analyzer by using commercial kits supplied from Roche Diagnostics. Low-density lipoprotein cholesterol (LDL) levels were calculated by using Friedewald’s formula. Clottable fibrinogen was quantified by using liquid thrombin reagent (DiaMed AG, Switzerland). Serum CRP levels were measured by turbidimetric assay. Turbidimetry is based on the measurement of the turbidity occurred immunoprecipitation of CRP in sera and the specific reagent including latex particles coated with antihuman CRP antibodies (Biosystems, USA). The intensity of the reaction is detected by an optical system comparing with the calibrators that gives a quantitative result. Sensitivity was 0.11 mg/l, and intra and interassay coefficients of variation were 5.0 and 6.5%, respectively. In this study, an automatic analyzer (SPACE, Schiparelli Biosystem Inc., USA) was used for detection of CRP levels in patient’s serum. 2.1. Statistical analysis Data was collected in a WINDOWS-based relational database (MICROSOFT EXCELL 2000) and analyzed with the Statistical Package for the Social Science (SPSS, version 11.0) for WINDOWS 98 (Microsoft Corp.). Values are given as mean9/ standard deviation (S.D.), or as mean9/S.D. and range, or as median and range. To compare women using the same HRT regimen for different duration with control group, one-way ANOVA or Kruskal/Wallis test was used. In addition, oneway ANOVA or Kruskal /Wallis test was also used to compare women receiving different types of HRT for the same duration. Data from the three different HRT treatment groups were compared with the control group data using Mann/ Whitney U -test or Student’s unpaired t-test.
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Because the distribution of CRP was skewed, logarithmic transformation was used. Correlations between variables were calculated with Pearson’s correlation coefficient. There was a significant difference between the groups in duration of amenorrhea (Tables 1 and 2); therefore, we analyzed between group differences with duration of amenorrhea as a second constant covariate. Statistical significance was defined as P B/0.05.
3. Results The participants were matched with respect to duration and the type of HRT (Tables 1 and 2). 3.1. Clinical characteristics Women receiving CEE/MPA for 3 months had a shorter mean duration of amenorrhea, compared with women not on HRT, and to those receiving transdermal 17b-E2/MPA, and oral 17b-E2/ NETA for 3 months (P B/0.05). In addition, mean duration of amenorrhea in women receiving transdermal 17b-E2/MPA for 12 months was longer than that of control group, of women taking oral 17b-E2/NETA, and of women taking oral CEE/MPA for 12 months (P B/0.05). Mean plasma FSH concentrations in women not on HRT were higher than those in women receiving any type of HRT either for 3 or 12 months (P B/0.05). Women receiving HRT for either 3 or 12 months had higher estradiol levels, compared with control group. Plasma FSH levels were both similar among all women receiving HRT for 3 months, but serum estradiol levels was higher in oral CEE/MPA group, than in transdermal 17b-E2/MPA and in oral 17b-E2/ NETA groups (P B/0.05). FSH and estradiol levels were all similar among women receiving any type of HRT for 12 months. All treatment groups and control group were similar with respect to age and BMI (Tables 1 and 2). 3.2. C-reactive protein CRP concentrations were significantly higher in women receiving oral 17b-E2/NETA (P /0.017)
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Table 1 Characteristics of women in control group and women receiving three different types of HRT for 3 months
Age (years) Duration of amenorhea (years) FSH (mIU/ml) Estradiol (pg/ml) Fibrinogen (mg/dl)e CRP (mg/l)e T-Chol. (mmol/l) TG (mmol/l) HDL (mmol/l) LDL (mmol/l) VLDL (mmol/l) BMI (kg/m2)
Control (n / 102)
Transdermal 17b-E2/MPA (n /21)
Oral 17b-E2/NETA (n /27)
Oral CEE/MPA (n / 33)
49.39/5.1 (40 / 62) 4.49/4.8 (1 /25)
49.59/4.6 (40 /60)
48.79/4.5 (40 /57)
47.59/4.8 (40 /59)
3.99/4.7 (1 /22)
3.69/2.8 (1 /10)
1.99/1.9 (1 /8)d
65.59/23.8 22.09/19.9 309 (180 /414) 0.48 (0.00 /1.23) 5.559/0.89 1.529/0.66 1.429/0.29 3.819/0.79 0.329/0.15 27.59/2.9
50.59/25.8a 34.29/27.6 300 (242 /388) 0.60 (0.00 /1.11) 5.249/0.90 1.589/0.60 1.329/0.38 3.519/0.80a 0.349/0.18 26.99/2.8
38.89/28.2b 54.49/36.0b 312 (175 /423) 0.90 (0.30 /1.54)b 5.159/0.81 1.569/0.56 1.359/0.31 3.499/0.64b 0.319/0.11 27.29/3.1
32.89/25.6c 95.19/44.9c 289 (220 /420) 0.78 (0.30 /2.12)c 5.249/0.83 1.689/0.63 1.419/0.34 3.499/0.73c 0.349/0.14 27.19/3.3
Values are given as mean9/S.D. or mean9/S.D. and range. FSH, follicle stimulating hormone; CRP, C-reactive protein; T-Chol., total cholesterol; TG, triglyceride; HDL, high density lipoprotein cholesterol; LDL, low density lipoprotein cholesterol; VLDL, very low density lipoprotein cholesterol; BMI, body mass index; MPA, medroxyprogesterone acetate; NETA, norethisterone acetate; E2, estradiol. Note: Statistics were performed on log-transformed data for CRP values. a Defines P B/0.05 value for comparison of transdermal 17b-E2/MPA group with control group. b Defines P B/0.05 value for comparison of oral 17b-E2/NETA group with control group. c Defines P B/0.05 value for comparison of oral CEE/MPA group with control group. d Defines P B/0.05 value for comparison of oral CEE/MPA group with control, transdermal 17b-E2/MPA and oral 17b-E2/ NETA. e Values are given as median and range.
and in CEE/MPA (P /0.0001) for 3 months than in women not on HRT. Median CRP level was slightly higher in women taking transdermal 17b-E2/MPA for 3 months compared with controls, but this difference was not statically significant (P /0.05, Table 1). When treatment groups receiving HRT for 12 months were compared with control group according to median plasma CRP levels, no significant differences were detected (Table 2). When the data were reanalyzed in relation to duration of HRT use, women receiving oral 17bE2/NETA for 3 months had a significantly higher CRP concentration compared with those taking oral 17b-E2/NETA for 12 months (P /0.035) (Fig. 1). In addition, women using CEE/MPA for 3 months had a significantly higher CRP level than that of women taking CEE/MPA for 12 months (P /0.045) (Fig. 2). CRP concentrations were almost similar among women receiving
transdermal 17b-E2/MPA irrespective of duration of use (Fig. 3). There were no significant correlations between CRP; and age, duration of menopause, plasma concentrations of FSH, estradiol, T-Chol., TG, HDL, LDL and VLDL. 3.3. Fibrinogen There were no statistical differences in median fibrinogen distributions between nonusers and any group of HRT users. The type and the duration of HRT use caused no significant changes in median plasma fibrinogen concentrations. 3.4. Lipids Serum LDL levels were more favorable in HRT users for 3 months. Mean LDL concentrations in every treatment groups receiving HRT for 3 months were lower than in women who were not
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Table 2 Characteristics of women in control group and women receiving three different types of HRT for 12 months
Age (years) Duration of amenorhea (years) FSH (mIU/ml) Estradiol (pg/ml) Fibrinogen (mg/dl)e CRP (mg/l)e T-Chol. (mmol/l) TG (mmol/l) HDL (mmol/l) LDL (mmol/l) VLDL (mmol/l) BMI (kg/m2)
Control (n / 102)
Transdermal 17b-E2/MPA (n /10)
Oral 17b-E2/NETA (n /16)
Oral CEE/MPA (n / 32)
49.39/5.1 (40 / 62) 4.49/4.8 (1 /25)
52.79/5.5 (45 /62)
48.99/5.6 (40 /60)
48.69/4.0 (40 /62)
8.09/5.9 (2 /20)d
4.99/4.3 (1 /14)
4.09/3.5 (1 /15)
65.59/23.8 22.09/19.9 309 (180 /414) 0.48 (0.00 /1.23) 5.559/0.89 1.529/0.66 1.429/0.29 3.819/0.79 0.329/0.15 27.59/2.9
37.39/25.6a 49.29/28.1a 284.5 (215 /355) 0.59 (0.00 /1.28) 5.519/1.22 1.459/0.52 1.669/0.31a 3.559/1.22 0.299/0.10 26.89/3.1
43.89/26.0b 49.39/26.1b 304 (213 /464) 0.53 (0.00 /0.90) 5.189/0.96 1.559/0.61 1.529/0.34 3.349/0.95 0.319/0.12 27.79/3.4
50.89/25.9c 43.59/23.1c 301.5 (224 /434) 0.62 (0.00 /1.23) 5.379/0.80 1.699/0.57 1.459/0.38 3.559/0.85 0.379/0.17 27.49/3.6
Values are given as mean9/S.D. or mean9/S.D. and range. FSH, follicle stimulating hormone; CRP, C-reactive protein; T-Chol., total cholesterol; TG, triglyceride; HDL, high density lipoprotein cholesterol; LDL, low density lipoprotein cholesterol; VLDL, very low density lipoprotein cholesterol; BMI, body mass index; MPA, medroxyprogesterone acetate; NETA, norethisterone acetate; E2, estradiol. Note: Statistics were performed on log-transformed data for CRP values. a Defines P B/0.05 value for comparison of transdermal 17b-E2/MPA group with control group. b Defines P B/0.05 value for comparison of oral 17b-E2/NETA group with control group. c Defines P B/0.05 value for comparison of oral CEE/MPA group with control group. d Defines P B/0.05 value for comparison of transdermal 17b-E2/MPA group with control, oral 17b-E2/NETA and oral CEE/ MPA. e Values are given as median and range.
Fig. 1. Median concentrations of CRP in women not on HRT, receiving oral 17b-E2/NETA for 3 or 12 months. * P /0.037, differences between women receiving 17b-E2/NETA for 3 months, and women receiving 17b-E2/NETA for 12 months, and women not on HRT (Kruskal /Wallis test). CRP, Creactive protein; NETA, norethisterone acetate.
Fig. 2. Median concentrations of CRP in women not on HRT, receiving oral CEE/MPA for 3 or 12 months. * P /0.0001, differences between women receiving oral CEE/MPA for 3 months, and women receiving oral CEE/MPA for 12 months, and women not on HRT (one-way ANOVA). CRP, C-reactive protein; CEE, conjugated equine estrogen; MPA, medroxyprogesterone acetate.
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Fig. 3. Median concentrations of CRP in women not on HRT, receiving transdermal 17b-E2/MPA for 3 or12 months. P / 0.05, differences between groups (Kruskal /Wallis test). CRP, C-reactive protein; MPA, medroxyprogesterone acetate.
taking any therapy (P B/0.05). Mean T-Chol. levels were lower in women taking HRT for 3 or 12 months compared with women on no therapy. But there were no statically significant differences in T-Chol. levels between non-user and HRT user groups. HDL level was higher in women receiving transdermal 17b-E2/MPA for 12 months compared with control group (P B/0.05), whereas other groups of HRT users were similar to control patients. Plasma levels of TG, HDL, and VLDL in patients receiving HRT for 3 months were also similar to those of control group. Moreover, plasma T-Chol., TG, LDL, VLDL levels in treatment groups for 12 months and control group were similar (Tables 1 and 2).
4. Discussion This study has revealed that each HRT regimen induces different changes in plasma CRP concentrations considered to predict future cardiovascular disease and those changes are dependent on the particular preparation, the duration of use and its route of administration. Recently published data indicate that CRP may be an independent risk marker for cardiovascular disease [9,15/17]. CRP concentrations are elevated
after myocardial infarction and this seems to be a predictor of future cardiovascular events [18,19]. There is increasing evidence that HRT increases plasma concentrations of CRP [10,20 /27]. The association between the increased CRP concentration and the administration of HRT has not been clarified yet. But as a result of oral HRT use, hepatic synthesis of this protein increases and an elevation in the level of CRP is seen [21,24]. It is presumed that an increase in CRP concentration is resulted in heightened plaque instability and a tendency to thrombosis and consequently, there is an increase in the risk of cardiovascular diseases [10,22]. Previous studies have showed that during the early period of treatment there was a rapid increase in CRP concentrations [21,28]. The most significant elevation of CRP values was seen in the first year of the treatment and this tended to sustain in subsequent years in the PEPI study [10]. In general, the short-term (1 /3 months) [21,24,29,30] and long-term (3 /5 years) [22,25] impacts of HRT on CRP were investigated in different studies performed thus far. Nevertheless, both short-term and long-term effects of HRT on CRP together have not been investigated in the same study yet. In this study, we investigated short-term (3 months) and long-term (12 months) effects of three different combined estrogen/progestin replacement therapy regimens that were administered either orally or transdermally on CRP plasma concentrations in healthy postmenopausal women. In the present study; the higher CRP levels found in 3 months combined oral HRT regimens indicated that oral route may cause a significant increase in CRP concentrations in early period of HRT. In some previous studies it was reported that postmenopausal women receiving long-term HRT had higher CRP levels [10,22,25]. However, in our study lower CRP levels were observed in women using long-term oral HRT compared with those using short-term. At present it seems that further studies are required to make a definite conclusion on this subject. Oral CEE alone or combined with progesterone was usually investigated in previous studies. In Europe, however, CEE are used to a lesser extend
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and increasing numbers of women are being prescribed either transdermal 17b-E2 or oral 17bE2. There were a few studies in literature about the effect of oral 17b-E2, especially transdermal estrogens, on CRP concentrations. In a small study by Vehkavaara et al., the concentration of CRP in transdermal estradiol users was not significantly higher than placebo group [29]. Two different investigators recently confirmed Vehkavaara’s results [25,31]. We found that short-term (3 months) and long-term (12 months) use of transdermal 17bE2/MPA had similar effects on CRP, those were not different from the control group. These finding were consistent with previous ones. The fact that difference observed between transdermal route, which had no significant effect on CRP irrespective of treatment duration, and oral route, which had a significant higher CRP level in short-term using may be explained by the hepatic first pass effect of oral estrogens [21,30,31]. All women enrolled in our study had intact uterus, in order to protect endometrium combined HRT was used. In most of the previous studies, it was reported that there was no any significant difference between women who used unopposed estrogen and combined estrogen/progestin therapy on CRP concentration, that is why it has been suggested that addition of progestin to treatment does not affect CRP concentration [10,20,21,25]. Therefore, we did not evaluate women who used unopposed estrogen. Fibrinogen is an acute phase reactant protein and a marker of risk of cardiovascular events and severity of atherosclerosis. It has been estimated that increased plasma fibrinogen level reflects the inflammatory state of the vascular wall. This inflammation has even been suggested to be the main mechanism of atherosclerosis [32]. Although some of the studies reported a decrease in fibrinogen levels with HRT use [12,33,34], some studies reported no change [13,21]. We did not detect any change in the median fibrinogen level during short and long-term treatment. In addition, the type and duration of HRT made no significant changes in plasma fibrinogen concentrations. Types of HRT and route of administration can affect serum lipids. Several randomized clinical trials have shown that oral administration of HRT
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reduces serum T-Chol. and LDL levels, and increase HDL levels in postmenopausal women [4,33,35,36]. In our study, patients on short-term HRT, irrespective of the type, had significantly lower LDL levels than women not on HRT. Moreover, in our study, serum T-Chol. levels were detected lower, but not statically significant, in all treatment groups. In previous studies included PEPI trial, serum HDL levels in women receiving combined estrogen replacement therapy were detected higher [3,33,35,36] but we did not observe any significant difference in women using oral combined estrogen replacement therapy with respect to HDL levels compared with women not on HRT. Additionally serum TG and VLDL levels were similar in all patients irrespective of the type or duration of treatment. Our study has some limitations; first it is a crosssectional study, second as most of the other researches on HRT, study groups include only healthy women who have a low risk for cardiovascular disease which may influence results [37], and third, all participants in our study received combined HRT which may preclude drawing conclusion regarding the effects of estrogen alone. The differential effect of various HRT regimens on some specific cardiovascular disease risk markers observed in this study had potentially important clinical implications. The effects of HRT on CRP and lipids depend on the preparation, or its route, or duration of administration. Our study suggests that, although short-term (3 months) oral combined HRT regimens have beneficial effects on serum lipids, there was a relationship between oral combined regimens and higher CRP concentrations. The increased risk of cardiovascular disease observed shortly after the onset of therapy in HERS in which high risk patients were given CEE combined with MPA [4] might be explained by this result mentioned above. We can suggest, based on the findings from our study that, the changes induced by some types of oral HRT regimens in short-term could further increase the risk of cardiovascular disease in women already at risk. For such women transdermal estrogen replacement therapy regimens might be a reasonable option.
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Even we may suggest that oral HRT increases the risk of cardiovascular events during short-term use, in order to make a clear-cut conclusion regarding the effect of transdermal or oral HRT on the risk of cardiovascular events during shortterm or long-term use further large controlled studies are required.
[12]
[13]
[14]
References [1] Wenger NK, Speroff L, Packard B. Cardiovascular health and disease in women. New Engl J Med 1993;329:247 /56. [2] Barrett-Connor E, Wenger NK, Grady D, et al. Hormone and nonhormone therapy for the maintenance of postmenopausal health: the need for randomized controlled trials of estrogen and raloxifene. J Women Health 1998;7:839 /47. [3] Hemminki E, McPherson K. Impact of postmenopausal hormone therapy on cardiovascular events and cancer: pooled data from clinical trials. Br J Med 1997;315:149 / 53. [4] Heart and estrogen/progestin replacement study (HERS) research group, Hulley S, Grady D, Bush T, et al. Randomized trial of estrogen plus progestin for secondary prevention of coronary heart disease in postmenopausal women. J Am Med Assoc 1998;280:605 /13. [5] Richards CD, Gauldie J. Role of cytokines in acute-phase response. In: Aggarwal BB, Puri RK, editors. Human cytokines: their role in disease and therapy. Cambridge, MA: Blackwell Science, 1995:253 /69. [6] Toss H, Lindahl B, Siegbahn A, Wallentin L. Prognostic influence of increased fibrinogen and C-reactive protein levels in unstable coronary artery disease. FRISC Study Group. Fragmin during instability in coronary artery disease. Circulation 1997;96:4204 /10. [7] Ridker PM, Buring JE, Shih J, Matias M, Hennekens CH. Prospective study of C-reactive protein and the risk of future cardiovascular events among apparently healthy women. Circulation 1998;98:731 /3. [8] Ridker PM, Glynn RJ, Hennekens CH. C-reactive protein adds to the predictive value of total, and HDL cholesterol in determining risk of first myocardial infarction. Circulation 1998;97:2007 /11. [9] Tracy RP, Lemaitre RN, Psaty BM, et al. Relationship of C-reactive protein to risk of cardiovascular disease in the elderly: results from the Cardiovascular Health Study and the Rural Health Promotion Project. Arterioscler Thromb Vasc Biol 1997;17:1121 /7. [10] Cushman M, Legault C, Barrett-Connor E, et al. Effect of postmenopausal hormones on inflammation-sensitive proteins: the postmenopausal estrogen/progestin interventions (PEPI) study. Circulation 1999;100:717 /22. [11] de Maat MP, Pietersma A, Kofflard M, Suluiter W, Kluft C. Association of plasma fibrinogen levels with coronary
[15]
[16] [17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
artery disease, smoking and inflammatory markers. Atherosclerosis 1996;121:185 /91. Fro¨hlich M, Schunkert H, Hense HW, et al. Effects of hormone replacement therapies on fibrinogen and plasma viscosity in postmenopausal women. Br J Haematol 1998;100:577 /81. Gordon EM, Williams SR, Frenchek B, Mazur CA, Speroff L. Dose-dependent effects of postmenopausal oestrogen and progestin on antithrombin III and factor XII. J Lab Clin Med 1988;111:52 /6. Boschetti C, Cortellaro M, Nenicioni T, Bertolli V, Volpe DA, Zanussi C. Short-and long-term effects of hormone replacement therapy (transdermal estradiol vs. oral conjugated equine estrogens, combined with medroxyprogesterone acetate) on blood coagulation factors in postmenopausal women. Thromb Res 1991;62:1 /8. Ridker PM, Hennekens CH, Buring JE, Rifai N. Creactive protein and other markers of inflammation in the prediction of cardiovascular disease in women. New Engl J Med 2000;342:836 /43. Pepys MB, Berger A. The renaissance of C reactive protein. Br Med J 2001;322:4 /5. Rifai N, Ridker PM. Proposed cardiovascular risk assessment algorithm using high-sensitivity C-reactive protein and lipid screening. Clin Chem 2001;47:28 /30. Lagrand WK, Visser CA, Hermens WT, et al. C-reactive protein as acardiovascular risk factor: more than epiphenomenon. Circulation 1999;100:96 /102. Strandberg TE, Tilvis RS. C-reactive protein, cardiovascular risk factors and mortality in a prospective study in the elderly. Arterioscler Thromb Vasc Biol 2000;20:1057 / 60. Ridker PM, Hennekens CH, Rifai N, Buring JE, Manson JE. Hormone replacement therapy and increased plasma concentration of C-reactive protein. Circulation 1999;100:713 /6. Van Baal WM, Kenemans P, Van der Mooren MJ, Kessel H, Emeis JJ, Stehouwer CDA. Increased C-reactive protein levels during short-term hormone replacement therapy in healthy postmenopausal women. Thromb Haemost 1999;81:925 /8. Cushman M, Meilahn EN, Psaty BM, Kuller LH, Dobs AS, Tracy RP. Hormone replacement therapy, inflammation and hemostasis in elderly women. Arterioscler Thromb Vasc Biol 1999;19:893 /9. Barinas-Mitchell E, Cushman M, Meilahn EN, Tracy RP, Kuller LH. Serum levels of C-reactive protein are associated with obesity, weight gain, and hormone replacement therapy in healthy postmenopausal women. Am J Epidemiol 2001;153:1094 /101. Luyer MDP, Khosla S, Owen WG, Miller VM. Prospective randomized study of effects of unopposed estrogen replacement therapy on markers of coagulation and inflammation in postmenopausal women. J Clin Endocrinol Metab 2001;86:3629 /34. Prelevic GM, Kwong P, Byrne DJ, Jagroop IA, Ginsburg J, Mikhalidis DP. A cross-sectional study of the effects of
M. Yilmazer et al. / Maturitas 46 (2003) 245 /253
[26]
[27]
[28]
[29]
[30]
[31]
hormone replacement therapy on the cardiovascular disease risk profile in healthy postmenopausal women. Fertil Steril 1996;77:945 /51. Yildirir A, Aybar F, Tokgo¨zog˘lu L, et al. Effects of hormone replacement therapy on plasma homocystein and C-reactive protein levels. Gynecol Obstet Invest 2002;53:54 /8. Skouby SO, Gram J, Andersen LF, Sidelmann J, Petersen KR, Jespersen J. Hormone replacement therapy: estrogen and progestin effects on plasma C-reactive protein concentrations. Am J Obstet Gynecol 2002;186:969 /77. Walsh BW, Paul S, Wild RA, et al. The effects of hormone replacement therapy and raloxifene on C-reactive protein and homocysteine in healthy postmenopausal women: a randomized, controlled trial. J Clin Endocrinol Metab 2000;85:214 /8. Vehkavaara S, Silveira A, Pietila TH, et al. Effects of oral and transdermal estrogen replacement therapy on markers of coagulation, fibrinolysis, inflammation and serum lipids and lipoproteins in postmenopausal women. Thromb Haemost 2001;85:619 /25. Herrington DM, Brosnihan KB, Pusser BE, et al. Differential effects of E and droloxifene on C-reactive protein and other markers of inflammation in healthy postmenopausal women. J Clin Endocrinol Metab 2001;86:4216 /22. Giltay EJ, Gooren LJG, Emeis JJ, Kooistra T, Stehouwer CDA. Oral ethinyl estradiol, but not transdermal 17b-
[32] [33]
[34]
[35]
[36]
[37]
253
estradiol, increases plasma C-reactive protein levels in men. Thromb Haemost 2000;84:359 /60. Ross R. The pathogenesis of atherosclerosis: a perspective for the 1990s. Nature 1993;3662:801 /6. The writing group for the PEPI trial. Effects of estrogen or estrogen/progestin regimens on heart disease risk factors in postmenopausal women: the postmenopausal estrogen/ progestin interventions (PEPI) trial. J Am Med Assoc 1995;273:199 /208. Salomaa V, Rasi V, Pekkanen J, et al. Association of hormone replacement therapy with hemostatic and other cardiovascular risk factors. The FINRISK hemostasis study. Arterioscler Thromb Vasc Biol 1995;15:1549 /55. Lobo RA, Pickar JH, Wild RA, et al. Metabolic impact of adding medroxyprogesterone acetate to conjugated estrogen therapy in postmenopausal women. Obstet Gynecol 1994;84:987 /95. Walsh BW, Schiff I, Rosner B, et al. Effects of postmenopausal estrogen replacement therapy on the concentration and metabolism of plasma lipoproteins. New Engl J Med 1991;325:1196 /204. Matthews KA, Kuller LH, Wing RR, Meillahn EN, Plantinga P. Prior use of estrogen replacement therapy, are users healthier than nonusers. Am J Epidemiol 1996;143:971 /8.