Capillary rarefaction in treated and untreated hypertensive subjects.

This study aimed to determine if capillary rarefaction is detectable and associated with endothelial dysfunction in persons with mild systolic blood pressure (SBP) elevation. Capillary density and endothelial function were quantified for 150 nondiabetic participants, grouped by blood pressure (BP) as normotensive, untreated high BP, and treated high BP. Structural capillary rarefaction measures were not different between the three groups. Functional capillary rarefaction measures were significantly lower in both high BP groups compared to normotensives, and correlated inversely with endothelial function. The study findings indicate that the hypertensive vascular pathologic process is already underway at modest levels of blood pressure elevation.