Determinants of urban-rural differences in cardiovascular risk factors in middle-aged women in India: a cross-sectional study.

Cardiovascular diseases (CVD) are the most important cause of death amongst middle-aged Indian women. To determine prevalence of CVD risk factors and their determinants we performed a nationwide study.Population based studies amongst women 35-70 years were performed in four urban and five rural locations in India. Location based stratified sampling was performed and we enrolled 4624 (rural 2616, urban 2008) of eligible 8000 women (58%). Demographic details, medical history, diet, physical activity and anthropometry were recorded using standardised techniques. Blood haemoglobin, glucose and total cholesterol were determined. Risk factors were diagnosed using current guidelines. Descriptive statistics are reported. Stepwise multivariate logistic regression was performed to identify determinants of urban-rural differences.In urban women mean body mass index (BMI), waist circumference, waist-hip ratio (WHR), systolic BP, haemoglobin, fasting glucose and cholesterol were significantly greater (p<0.01). Age-adjusted prevalence of risk factors (%) in urban vs rural was of obesity BMI ≥ 25 kg/m(2) (45.6 vs 22.5), truncal obesity WHR>0.9 (44.3 vs 13.0), hypertension (37.5 vs 29.3), hypercholesterolemia ≥ 200 mg/dl (27.7 vs 13.5), and diabetes (15.1 vs 4.3) greater whilst any tobacco use (19.6 vs 41.6) or smoking lower. Significant determinants of urban-rural differences were greater income and literacy, dietary fats, low physical activity, obesity and truncal obesity (p<0.01).Greater prevalence of CVD risk factors in urban middle-aged women is explained by greater income and literacy, dietary fat, low physical activity and obesity.