Recent trends in coronary heart disease epidemiology in India

Coronary heart disease (CHD) is epidemic in India and one of the major causes of disease-burden and deaths. Mortality data from the Registrar General of India shows that cardiovascular diseases are a major cause of death in India now. Studies to determine the precise causes of death in urban Chennai and rural areas of Andhra Pradesh have revealed that cardiovascular diseases cause about 40% of the deaths in urban areas and 30% in rural areas. Analysis of cross-sectional CHD epidemiological studies performed over the past 50 years reveals that this condition is increasing in both urban and rural areas. The adult prevalence has increased in urban areas from about 2% in 1960 to 6.5% in 1970, 7.0% in 1980, 9.7% in 1990 and 10.5% in 2000; while in rural areas, it increased from 2% in 1970, to 2.5% in 1980, 4% in 1990, and 4.5% in 2000. In terms of absolute numbers this translates into 30 million CHD patients in the country. The disease occurs at a much younger age in Indians as compared to those in North America and Western Europe. Rural-urban differences reveal that risk factors like obesity, truncal obesity, hypertension, high cholesterol, low HDL cholesterol and diabetes are more in urban areas. Case-control studies also confirm the importance of these risk factors. The INTERHEART-South Asia study identified that eight established coronary risk factors--abnormal lipids, smoking, hypertension, diabetes, abdominal obesity, psychosocial factors, low fruit and vegetable consumption, and lack of physical activity--accounted for 89% of the cases of acute myocardial infarction in Indians. There is epidemiological evidence that all these risk factors are increasing. Over the past fifty years prevalence of obesity, hypertension, hypercholesterolemia, and diabetes have increased significantly in urban (R2 0.45-0.74) and slowly in rural areas (R2 0.19-0.29). There is an urgent need for development and implementation of suitable primordial, primary, and secondary prevention approaches for control of this epidemic. An urgent and sincere bureaucratic, political, and social will to initiate steps in this direction is required.