Urbanization and coronary heart disease: a study of urban-rural differences in northern India.

BACKGROUND: In the West, urbanization has been accompanied by a rise in the rate of coronary heart disease. This trend has gone hand in hand with an increased consumption of processed, energy-dense food and dependence on machines for physical work. To examine whether a similar trend is underway in northern India, the prevalence of and risk factors for coronary heart disease were compared in rural, semi-urban and urban communities. METHODS AND RESULTS: A total of 7,169 adults were interviewed and examined during 1995-2000 in cross-sectional cluster sample surveys from a rural area of Haryana (Raipur Rani block), two semi-urban areas of Punjab (Mandi Gobindgarh and Morinda), and Chandigarh city. The study, which covered people in the age-group of 35+ years, also estimated the lipid, glucose and insulin levels of a sub-sample of 186 persons who did not have coronary heart disease or hypertension. The prevalence of coronary heart disease among males in the villages, towns and city was 1.7%, 2.5% and 7.4%, respectively, and among females, 1.5%, 3.4% and 7.1%,respectively. The age- and sex-adjusted prevalence odds ratio of coronary heart disease, in comparison to the villages, was 1.9 (95% CI; 1.1-3.2) in the towns and 4.9 (95% CI: 2.9-8.2) in the city. Hypertension, diabetes, obesity and physical inactivity were significantly more common in the urban areas, while the rate of tobacco smoking was significantly higher in the rural areas ( p< 0.05). The alcohol consumption rates for the urban and rural communities were similar (p> 0.05). The quantity of the food items commonly consumed, as well as the frequency with which particular items were consumed, varied across the rural, semi-urban and urban areas ( p< 0.05). The urban population had significantly higher levels of lipids and serum insulin than did the rural population, but a lower level of plasma glucose ( p< 0.05). CONCLUSION: The urban way of living is leading to an increase in the prevalence of the well-known risk factors for, as well as the rate of, coronary heart disease. Attempts to preserve the traditional lifestyle are necessary in order to prevent an epidemic of coronary heart disease in the developing countries.