The relationship between blood pressure and serum insulin response in glucose intolerant subjects

One hundred newly diagnosed IGT and type 2 diabetic subjects both normotensive and hypertensive and of age between 40-55 years were studied by oral glucose stimulation. Serum insulin concentrations were measured in the fasting and at 30, 60 and 120 minutes after glucose administration. Postglucose serum insulin responses were found to be significantly higher in the hypertensive subjects with FPG < 7.8 mmol/l (p < 0.05 at 30, 60 and 120 minutes) as compared with the corresponding values of the normotensive subjects with comparable fasting hyperglycemia. No significant difference in insulin responses between hypertensive and normotensive subjects was found in those with FPG > 7.8 mmol/l. A positive correlation was observed between diastolic blood pressure and 2 hour postglucose serum insulin concentration in those with FPG < 7.8 mmol/l (P < .05). The results suggested that hyperinsulinemia is a feature of hypertensive subjects with mild glucose intolerance and not of those with severe glucose intolerance. The absence of elevated insulin response in hypertensive subjects with advanced type 2 diabetes might be due to severe B cell decompensation. It appears that insulin resistance is somehow associated with essential hypertension and hyperinsulinemia is not necessary for the maintenance of raised blood pressure.