Hypertension and insulin resistance in a native unindustrialised rural population of India.

A cross-sectional survey of 2964 individuals aged 16-70 years from a rural area of North India was carried out to test the hypothesis that a rural unindustrialised hypertensive population of North India has central obesity and hyperinsulinemia. Oral glucose tolerance test was carried out on 68 newly detected hypertensives, 82 age- and sex-matched community controls and 58 genetically related members of hypertensives (family controls). Fasting blood samples were examined for plasma glucose, serum insulin and lipids. Postglucose-load blood samples were examined for plasma glucose and serum insulin. Three blood pressure readings were recorded using Random Zero Sphygmomanometer. Anthropometric measurements (waist-hip ratio, subscapular and triceps skinfold thickness) of all three groups of individuals (hypertensives, community controls and family controls) were also recorded. The hypertensives had significantly higher fasting and postglucose-load serum insulin levels (P<0.05), body mass index (21.3 vs. 19 kg/m2: P<0.05), waist-hip ratio (0.89 vs. 0.85: P<0.001), subscapular (18.5 mm vs. 12.7 mm: P<0.001) and triceps fold thickness (17.6 mm vs. 12.9 mm: P<0.05) than community controls. The family controls had significantly higher systolic blood pressure than community controls (P<0.05). The lipids were not significantly different in all the three groups. Multiple logistic regression showed that both fasting and postglucose-load serum insulin were significantly associated with hypertension independent of waist-hip ratio and body mass index. The results of the present study suggest that hyperinsulinemia is related to hypertension in a rural unindustrialised population of North India.