Borderline hypertension in young patients is associated with reduced capillary density, which inversely correlates with cardiac index (r = -0.482, p<0.01) rather than blood pressure.
Observational (n=34)
Is high-output borderline hypertension associated with attenuation of the microcirculation compared to normotensive controls?
The high cardiac output phase of early essential hypertension is accompanied by capillary rarefaction, which correlates more closely with elevated cardiac output than with raised blood pressure.
Effect estimate: r = -0.482
p-value: p=<0.01
Previous studies have shown abnormalities of the microvasculature in the spontaneously hypertensive rat and human subjects with established hypertension. We have studied the conjunctival microvasculature in relation to systemic and forearm hemodynamics in 24 normal subjects (NL) and 10 subjects with intermittent elevation of blood pressure (BHT). Macrophotographs of the conjunctival circulation were measured for arteriolar diameter and density of arterioles, capillaries, and venules. Blood pressure was measured by Arteriosonde, cardiac index by echocardiography, and forearm hemodynamics by mercury-filled strain-gauge venous occlusion plethysmography. Average diastolic blood pressure in the NL group was 74 +/- 1.7 mm Hg, while that of the BHT subjects was 89 +/- 3.1 mm Hg (p less than 0.005). Capillary density, venous density, and total vascular density were significantly lower in the BHT than NL group, while arteriolar density did not differ significantly. Cardiac index was significantly higher, and peripheral vascular resistance significantly lower, in the BHT as compared to the NL subjects. Forearm blood flow was higher in the NL subjects. The diameter of the preterminal arterioles of the BHT subjects was 27% greater than NL (p less than 0.02). The capillary density was inversely related to the cardiac index (r = -0.482, p less than 0.01), but was not related to blood pressure (r = -0.207). We conclude that the high cardiac output phase of early essential hypertension in humans is accompanied by a reduction in the number of filtering capillaries, and that the rarefaction of capillaries is more closely related to the elevation of cardiac output than to raised blood pressure.
Sullivan et al. (Tue,) conducted a observational in Borderline hypertension (n=34). Intermittent elevation of blood pressure (borderline hypertension) vs. Normal subjects was evaluated on Capillary density correlation with cardiac index (r = -0.482, p=<0.01). Borderline hypertension in young patients is associated with reduced capillary density, which inversely correlates with cardiac index (r = -0.482, p<0.01) rather than blood pressure.