Fetal growth and coronary heart disease in South India

Background Coronary heart disease is predicted to become the commonest cause of death in India within 15 years. People from India living overseas already have high rates of the disease that are not explained by known coronary risk factors. Small size at birth is a newly described risk factor for coronary heart disease, but associations between size at birth and the disease have not been examined in India. Methods We studied 517 men and women who were born between 1934 and 1954 in a mission hospital in Mysore, South India, and who still lived near to the hospital. We related the prevalence of coronary heart disease, defined by standard criteria, to their birth size. Findings 25 (9%) men and 27 (11%) women had coronary heart disease. Low birthweight, short birth length, and small head circumference at birth were associated with a raised prevalence of the disease. Prevalence fell from 11% in people whose birthweights were 5·5 Ib (2·5 kg) or less to 3% in those whose birthweights were more than 7 Ib (3·1 kg), p for trend=0·09. The trends were stronger and statistically significant among people aged 45 years and over (p=0·03 for birthweight, 0·04 for length, and 0·02 for head circumference). High rates of disease were also found in those whose mothers had a low body weight during pregnancy. The highest prevalence of the disease (20%) was in people who weighed 5·5 Ib (2·5 kg) or less at birth and whose mothers weighed less than 100 Ib (45 kg) in pregnancy. These associations were largely independent of known coronary risk factors. Interpretation In India, as in the UK, coronary heart disease is associated with small size at birth, suggesting that its pathogenesis is influenced by events in utero. The association with low maternal bodyweight is further evidence that the disease originates through fetal undernutrition. Prevention of the rising epidemic of the disease in India may require improvements in the nutrition and health of young women.