Epidemiologic study of diet and coronary risk factors in relation to central obesity and insulin levels in rural and urban populations of north India.

In a population survey of 162 rural and 152 urban subjects aged 26-65 years at Moradabad, the findings are compared with existing data on Indian immigrants to Britain and United States. In comparison with rural subjects, urban subjects had a higher prevalence of coronary artery disease (8.6 vs. 3.0%) and diabetes (7.9 vs 2.5%), higher blood pressures, total and low density lipoprotein cholesterol, triglycerides and postprandial 2-h blood glucose and plasma insulin similar to observations made in UK in immigrants compared to Europeans. Fasting plasma insulin and high density lipoprotein cholesterol levels in urban subjects were comparable with rural subjects. Mean body weights were significantly higher in urban women, but not in men, than in rural subjects. However the body mass index (22.9 +/- 4.2 vs. 21.6 +/- 2.4 kg/m2) and waist-hip girth ratio (0.89 +/- 0.10 vs. 0.86 +/- 0.07) were significantly higher in urban men compared to rural men without such differences in women. Underlying these differences in risk factors, urban subjects had three times better socioeconomic status than rural subjects and were eating higher total and saturated fat, cholesterol and refined carbohydrates and lower total and complex carbohydrates compared to rural men and women. Energy expenditure during routine and spare time physical activity was significantly higher in rural compared to urban subjects. Those patients who had risk factors, showed lesser physical activity and had greater adverse factors in the diet compared to subjects without risk factors. Body mass index and waist-hip girth ratio in patients with risk factors were significantly higher than in subjects without risk factors. The findings suggest that decreased consumption of total and saturated fat and increased physical activity may be useful for prevention of coronary artery disease among urbans as well as in immigrants.