HYPERINSULINEMIA, CIRCADIAN VARIATION OF BLOOD-PRESSURE AND END-ORGANDAMAGE IN HYPERTENSION

Background: Some patients with essential hypertension display hyperins ulinemia and/or insulin resistance, A relationship between hyperinsuli nemia and blood pressure has not been conclusively established, Some e vidence points to a relationship between hyperinsulinemia and evidence of cardiovascular damage, Objectives: In this study, we examined the relationship between insulin secretion in response to an oral glucose load, circadian variation of blood pressure, and evidence of vascular damage, measured by the thickness of the carotid artery and urinary al bumin excretion. Design: Seventy patients with essential hypertension and 35 healthy volunteers were included in the study, Results: Twenty patients were hyperinsulinemic, Office blood pressure was not differen t between hypertensive patients with high and those with normal insuli n AUC. However, night-time diastolic blood pressure was greater in hyp ertensive patients with high insulin AUC (93+/-2.9 mm Hg) than in thos e with normal insulin AUC (83.5+/-1.7 mm Hg, P<0.005). The thickness o f the carotid artery and urinary albumin excretion were greater (P<0.0 5) in patients with high insulin AUC than in patients with normal insu lin AUC and normotensive subjects, Insulin AUC was significantly corre lated with ambulatory blood pressure, carotid artery thickness, and ur ine albumin excretion. Multiple regression analysis using insulin AUC as the dependent variable and UAE, triglycerides, body-mass index and office or ambulatory blood pressure as independent variables showed th e strongest correlation with urine albumin excretion (P<0.0001), trigl ycerides (P<0.02) and body-mass index (P<0.07). Conclusions: These dat a suggest that in patients with essential hypertension hyperinsulinemi a is associated with higher levels of nocturnal blood pressure, and gr eater evidence of vascular damage.