Dark chocolate improves arterial stiffness and endothelial function

AJH–May 2004 –VOL. 17, NO. 5, PART 2

a volume-oscillometric method (Artcomp®, Critikon®). Atrial and brain natriuretic peptides (Nt-proANP and Nt-proBNP) were measured by immunoassay (Elecsys®, Roche Diagnostics®). Results: BP was 164⫾28/89⫾16 mmHg and HR 69⫾12 bpm. BAC was 22⫾7.1 ␮l/mmHg/10 cm and BAD was 17⫾5.9 103mmHg-1 at a transmural pressure of 0 mmHg. Nt-proANP was 1406⫾642 pmol/l and Nt-proBNP was 65⫾10 pmol/l. Nt-proBNP correlated to BAC and BAD (r⫽ ⫺0.32, p⬍0.05 and r⫽ ⫺0.25, ns). Nt-proANP correlated only insignificantly to BAC and BAD (r⫽ ⫺0.19 and r⫽ ⫺0.17, both ns). No relation was seen between the neurohormones and the arterial volume. Conclusion: The negative correlation observed between BAC and Nt-proBNP might reflect the known association between neurohormones and wall stress in the left ventricle. The absent correlation between neurohormones and BAD and arterial volume could indicate a more important relation to arterial wall structure rather than arterial diameter at the relaxed state of the vessel as investigated in this study. Key Words: Arterial Compliance, Neurohormones, Hypertension

P-288 MENTAL STRESS HAS AN UNFAVORABLE EFFECT ON AORTIC STIFFNESS AND WAVE REFLECTION Charalambos Vlachopoulos, Foteini Kosmopoulou, Nikolaos Alexopoulos, Konstantinos Aznaouridis, Nikolaos Ioakeimidis, Ioanna Dima, Christodoulos Stefanadis. Cardiology, Athens Medical School, Athens, Greece; Cardiology, “Henry Dynant” Hospital, Athens, Greece. Large artery stiffness and wave reflection are important prognosticators of cardiovascular risk and are involved in the pathogenesis of hypertension. Mental stress has been linked to increased morbidity and mortality, however, its effect on arterial elastic properties has not been defined. We studied 10 healthy volunteers (age 28⫾3 years) in a randomized, double-blind, crossover fashion (mental stress for 3 minutes and placebo). Carotid-femoral pulse wave velocity was measured as an index of aortic stiffness using a validated non-invasive device (Complior®). Wave reflection was studied using a validated system (Sphygmocor®) that employs (i) high-fidelity arterial tonometry (Millar tonometer) for the non-invasive registration of radial pulse waveform and (ii) appropriate computer software for pulse wave analysis. Aortic pressure waveform was synthesized from the radial waveform using a generalized transfer function. Augmentation index was measured as an index of wave reflection. Mental stress led to a substantial increase in pulse wave velocity (by 0.40 m/sec, P⬍0.05) and augmentation index (by 4.9%, P⬍0.05) indicating increased aortic stiffness and increased effect of wave reflection from the periphery (figure). These effects were accompanied by an increase in peripheral and central systolic pressure (by 4.4 and 3.9 mmHg respectively, P⬍0.05). Mental stress induces an acute deterioration in arterial stiffness. This finding provides new insights into the unfavourable effects of mental stress on the cardiovascular system and may be involved in the pathogenesis of hypertension.

Key Words: Mental Stress, Arterial Stiffness, Hypertension

POSTERS: Arterial Structure and Compliance

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P-289 DARK CHOCOLATE IMPROVES ARTERIAL STIFFNESS AND ENDOTHELIAL FUNCTION Konstantinos Aznaouridis, Charalambos Vlachopoulos, Nikolaos Alexopoulos, Nikolaos Ioakeimidis, Dorothea Tsekoura, Christos Pitsavos, Christodoulos Stefanadis. Cardiology, Athens Medical School, Athens, Greece. Recent studies highlight the favorable effects of dark chocolate on the antioxidant status, mainly attributable to its polyphenol content. Arterial stiffness and endothelial function are prognosticators of cardiovascular risk. The purpose of this study was to examine the effect of dark chocolate on arterial stiffness and endothelial function. We studied in two different days 10 healthy volunteers (28.4⫾2 years) in a randomized, single-blind, crossover fashion (eating 100mg of dark chocolate 74% rich in cocoa and sham eating). Wave reflection, which is an index of arterial stiffness and left ventricular afterload, was studied using a validated system (SphygmoCor®) that employs high-fidelity arterial tonometry and appropriate computer software for pulse wave analysis. Augmentation index was measured as an index of wave reflection. Higher values of augmentation index indicate increased arterial stiffening and wave reflection and vice-versa. Endothelial function was evaluated with flow-mediated dilatation (FMD) of the brachial artery after reactive hyperemia induced by cuff occlusion using high-resolution ultrasonography (10.5 MHz). Chocolate led to an increase in aortic systolic and diastolic pressures (by 4.0 and 3.8 mmHg, respectively). Despite this, there was a substantial decrease in augmentation index (by 2.9%, left figure) that denotes decrease in wave reflection along the arterial tree. Resting brachial diameter and FMD increased (by 0.17 mm, middle figure, and by 1.1%, right figure), denoting improvement in endothelial function. In conclusion, dark chocolate rich in cocoa leads to an acute improvement in arterial stiffness and endothelial function. This finding provides further insights into the favorable effects of chocolate to the cardiovascular system.

Key Words: Chocolate, Arterial Stiffness, Endothelial Function

P-290 EFFECTS OF FLUVASTATIN ON NONENDOTHELIUM DEPENDENT VASODILATATION FUNCTION IN HYPERENSIVES Liangdi Xie, Yuerong Yang, Ming Sun, Xin Wu. Hypertension, First Affiliated Hospital, Fujian Medical College, Fuzhou, Fujian, China; Department of Cardiology, Fujian Geriatric Hospital, Fuzhou, Fujian, China; Department of Cardiology, Xiangya Hospital of Central South University, Changsha, Hunan, China. This study was to investigate the effect of fluvastatin on the nonendothelium dependent vasodilatation function in hypertensives. 55 mild to moderate glade I-II hypertensives were recruited to receive fluvastatin 20 – 40 mg daily in addition to regular treatment irrespective of plasma lipid level, while 37 hypertensives under regular antihypertensive treatment served as control. Intima-media thickness (IMT) of right carotid (CA), brachial(BA), femoral(FA) and tibial arteries(TA) were measured using Acuson 128X110 sonography. Endothelium-dependent vascular function (⌬Dia-P) was determined by the percentage changes in vessel diameter after 5 min compression.Non endothelium-dependent vascular function (⌬Dia-N) was detected after a single dose of 0.4 mg nitroglyc-