Prevalence and risk factors of hypertension in a selected South Indian population--the Chennai Urban Population Study

Hypertension is a major public health problem in developing countries. There is however very little population based data particularly in South India. The aim of this study is to determine the prevalence of hypertension and its associated risk factors in an urban South Indian population at Chennai. The Chennai Urban Population Study (CUPS) is an epidemiological study involving two residential areas in Chennai in South India. Of the total of 1399 eligible subjects (age > or = 20 years), 1262 (90.2%) participated in the study. All the study subjects underwent a glucose tolerance test (GTT) and were categorized as having normal glucose tolerance (NGT), impaired glucose tolerance (IGT) or diabetes mellitus (DM). Subjects were classified as hypertensive using the criteria, systolic blood pressure (SBP) > or = 140 mm Hg, and/or diastolic blood pressure (DBP) > or = 90 mm Hg and/or treatment with anti-hypertensive drugs. Twelve-lead resting electrocardiography (ECG) was performed in 1175 individuals and peripheral Doppler studies were done in 50% of the individuals (n=631). The overall crude prevalence of hypertension (HTN) in this population is 21.1% (n=266) while the age standardized prevalence is 17.0%. Body mass index (BMI) and waist-hip ratio (WHR) were significantly higher (p < 0.001) in the HTN group compared to the non-hypertensive individuals. The prevalence of diabetes (p < 0.001), obesity (p < 0.001), CAD (p = 0.001) and PVD (p = 0.0055) was higher among the hypertensive compared to normotensive group. Multiple logistic regression analysis revealed HTN to be significantly associated with age (p < 0.001), body mass index (p < 0.001) and glucose intolerance (p = 0.005). The prevalence of hypertension appears to be high in this urban South Indian population and this calls for urgent steps for its prevention and control.