Abstract
BACKGROUND: Rates of coronary heart disease (CHD) in India are rising, and are now similar to those in Western countries. The prevalence of conventional CHD risk factors such as hypercholesterolaemia, hypertension, smoking and obesity, tend to be lower in Indian than Western populations, and fail to explain these high rates of disease. Increased left ventricular (LV) mass and decreased arterial compliance predict a higher risk of CHD in Western populations, but there are no published data from India. We have measured LV mass and arterial compliance, and examined their relation to CHD and other known risk factors, in men and women living in Mysore, South India. METHODS: We examined 435 men and women born in Mysore during 1934-1953. LV mass was measured by echocardiography and arterial compliance (derived from pulse wave velocity, PWV) was measured by a non-invasive optical method in three arterial segments. RESULTS: The mean LV mass was 149 g (S.D. 37) in men and 125 g (S.D. 32) in women. The mean PWV was 4.14 m/s in the aorto-radial, 3.28 m/s in the aorto-femoral and 13.59 m/s in the femoro-popliteal-posterior tibial segments. LV mass and PWV were positively correlated with each other and with systolic and diastolic blood pressures, non-insulin dependant diabetes mellitus, fasting plasma glucose, insulin, proinsulin concentrations and serum triglyceride concentrations (p<0.05 for all), independently of age, sex and body size. In addition, LV mass correlated negatively with fasting serum HDL-cholesterol (p=0.02). Higher LV mass was associated with an increased risk of CHD (p=0.05). CONCLUSIONS: The mean LV mass in this Indian population is low compared with Western populations, though as in the West, increased LV mass is associated with an increased risk of CHD. Greater LV mass and reduced arterial compliance are associated with higher levels of many known CHD risk factors especially with those which form the Insulin Resistance Syndrome.