Differences in body mass index and waist : hip ratios in North Indian rural and urban populations

Overweight could be a major factor in determining the increasing rates of coronary heart disease in the Indian population, by its influence on blood pressure, diabetes and insulin resistance. We studied the prevalence of overweight in north Indian urban and rural population samples. The urban sample population (n = 3050) was selected using a multistage sampling with stratification for geographical zone and the type of residential colony and cluster sampling of urban blocks in each stratum. The rural sample (n = 2487) was selected by random sampling of villages stratified for population size followed by coverage of all eligible persons in the village. All participating individuals were 35-64 years of age. Women constituted 52.2% (n = 1594) and 57% (n= 1417) of urban and rural samples, respectively. The study reveals that overweight is widely prevalent in the adult urban Delhi population, whereas underweight is a significant problem in the rural population. This was noted across all the age groups in both men and women. We estimated 'comprehensive coronary risk estimates' based on the New Zealand Heart foundation guidelines and noted that the proportion of high and very high risk subjects increased in a continuous manner even within the 'normal' ranges of BMI. This difference in prevalence in the urban population could represent the demographic transition in the Indian population.