Functional capillary rarefaction in mild blood pressure elevation.

Capillary rarefaction is described in patients with moderate to severe hypertension. The study objective was to determine if structural and/or functional capillary rarefaction is detectable and associated with endothelial dysfunction in patients with mild blood pressure elevation (HBP: Systolic blood pressure 130 - 160 mm Hg). Capillary density was quantified by direct capillaroscopy in 110 nondiabetic black and non-black subjects. Endothelial function was quantified by plethysmographic measures of flow-mediated vasodilation. Compared to normotensives (NBP: N = 90), functional capillary rarefaction was detected in HBP (N = 20; P<0.001). Functional capillary density measures correlated with endothelial function (P<0.001). Functional, but not structural, capillary rarefaction is detectable and associated with endothelial dysfunction in both black and non-black individuals with mild blood pressure elevation.