Factor VII hyperactivity and endothelial cell damage are found in elderly hypertensives only when concomitant with microalbuminuria

Abstract

We studied the relationships among albuminuria, factor VII (FVII) hyperactivity, and endothelial cell damage in 61 elderly hypertensive subjects. The plasma levels of activated FVII (FVIIa), FVII coagulant activity, FVII antigen (FVIIag), von Willebrand factor (vWF), and thrombomodulin were measured to assess FVII hyperactivity and endothelial cell damage, and urinary albumin excretion rate (UAE) was calculated using 12-hour nighttime (7 PM to 7 AM) urine collection (mean for 2 consecutive nights). We performed 24-hour ambulatory blood pressure monitoring in all 61 hypertensive patients and classified them into a white-coat hypertension group (n=12) and a sustained hypertension group (n=49). For the levels of FVII, vWF, and thrombomodulin, there were no differences between the white coat hypertension group and normotensive control subjects (n=25). In the sustained hypertensive group, only the microalbuminuric subgroup (UAE, 15 to 300 μg/min: n=30) showed significant elevation compared with the normotensive group for the level of FVIIa (mean [95% confidence interval]: 4.0 [3.6 to 4.4] versus 3.0 [2.6 to 3.3] ng/mL, P <15 μg/min, n=19) differed from that in the normotensive control group. These results suggest that among elderly hypertensives, only those with microalbuminuria show enhancement of FVII activation and endothelial cell damage, while patients with white-coat hypertension and normoalbuminuric hypertensives do not show these accompanying abnormalities. Thus, increased levels of FVII activity and markers of endothelial cell damage might account for the higher risk of cardiovascular events in essential hypertension with microalbuminuria.