Individuals at increased coronary heart disease risk are characterized by an impaired microvascular function in skin

Background: To investigate whether microvascular function in skin is a valid model to study the relationships between cardiovascular risk factors and microvascular function, we investigated skin microvascular function in individuals with increased coronary heart disease (CHD) risk. Materials and methods: Forty-six healthy White individuals aged 30-70 years were studied. Coronary heart disease risk was assessed with the use of the CHD risk score according to the Framingham Heart Study, which is based on the risk factors age, blood pressure, cigarette smoking, total cholesterol, HDL cholesterol and diabetes. Endothelium-dependent and -independent vasodilation in skin were evaluated with laser Doppler after iontophoresis of acetylcholine and sodium nitroprusside. Videomicroscopy was used to measure recruitment of skin capillaries after arterial occlusion. Results: Coronary heart disease risk score (i.e. the 10-year probability of CHD) varied from 1-37%. Microvascular function decreased with increasing quartiles of CHD risk (for acetylcholine-mediated vasodilation: 687, 585, 420 and 326%, P = 0.002; for nitroprusside-mediated vasodilation: 776, 582, 513 and 366%, P = 0.02; for capillary recruitment: 49.9, 44.6, 27.2 and 26.7%, P = 0.001). These trends were similar in men and women (P for interaction > 0.2) and independent of body mass index. Conclusions: Increased CHD risk is associated with an impaired endothelium-dependent vasodilatation and capillary recruitment in skin, suggesting that microvascular function in skin is a valid model to study the relationships between cardiovascular risk factors and microvascular function.