Rarefaction of skin capillaries in normotensive offspring of individuals with essential hypertension.

Abstract

Rarefaction of skin capillaries in people with intermittent borderline essential hypertension suggests a primary or an early abnormality that may antedate the onset of sustained hypertension. To compare skin capillary density in subjects with and without a family history of essential hypertension. 21 normotensive individuals, one or both of whose parents had essential hypertension (mean age 39.3 years; blood pressure 124/79 mm Hg); 21 normotensive controls with no family history of hypertension (age 46.3 years; blood pressure 124/78 mm Hg). The skin of the dorsum of the fingers was examined by intravital capillary microscopy before and after venous congestion at 60 mm Hg for two minutes. By analysis of variance, both baseline and maximum skin capillary density were lower in subjects with a family history of essential hypertension than in those with no family history (baseline: 67 v 79 capillaries per field, p = 0.008; maximum: 74 v 93 capillaries per field, p < 0.0005). Capillary rarefaction in essential hypertension may occur before the increase in blood pressure and could, at least in part, reflect a primary rather than a secondary abnormality.