Insulin Resistance and Hypertension in Non-obese Africans in Tanzania

Insulin sensitivity was assessed using a glucose-insulin infusion test in 15 newly diagnosed non-obese hypertensive black Tanzanians with normal glucose tolerance and in 15 normotensive control subjects matched for age, sex, and body mass index. The steady-state blood glucose and metabolic clearance rate of glucose (MCR) were used as measures of insulin sensitivity. The mean MCR (glucose) was significantly reduced (7.12 +/- 0.57 versus 9.50 +/- 0.69 micro mol/kg per minute; P < .05) and mean steady-state blood glucose was significantly elevated (5.0 +/- 0.3 versus 3.7 +/- 0.3 mmol/L; P < .01) in subjects with hypertension compared with the normotensive group. For all subjects there was a significant inverse correlation between MCR (glucose) and systolic (P = .003) and diastolic (P = .005) blood pressure; and a positive correlation was found between fasting serum insulin levels and systolic (P = .005) and diastolic (P = .004) blood pressure. These observations were independent of body mass index and serum lipid levels. These data indicate a strong association between insulin mediated glucose uptake and blood pressure in this population of normal weight untreated urban Africans. (Hypertension. 1998;31[part 1]:114-118.)