Change in prevalence of Coronary Heart Disease and its risk between 1991-94 to 2010-12 among rural and urban population of National Capital Region, Delhi

Objectives We aimed to measure the change in prevalence of Coronary Heart Disease (CHD) and Cardiovascular Diseases (CVDs) risk among those aged 35–64 years in urban and rural areas of National Capital Region (NCR) of Delhi, between 1991-1994 (survey 1) and 2010–2012 (survey 2). Methods Both surveys used similar sampling methodology and mean ages of participants were similar. A total of 3048 and 2052 subjects were studied in urban Delhi and 2487 and 1917 participants recruited from rural Ballabgarh in survey 1 and in survey 2 respectively. CHD was diagnosed based on a Minnesota coded ECG and Rose angina questionnaire. Data on behavioural, physical, clinical and biochemical parameters were collected using standard methods. CVD Risk of participants was calculated using the gender specific Framingham risk equation. Results The age and sex standardised prevalence of CHD in urban Delhi increased from 10.3% (95% CI: 9.2–11.4) to 14.1% (95% CI: 12.6–15.6) between the two surveys as compared to an increase from 6.0% (95% CI: 5.0–6.9) to 7.4% (95% CI: 6.3–8.6) in rural Ballabgarh. The highest increase in the prevalence of CHD was reported among urban women (10.1% to 16.6%).The proportion of population with high 10-year CVD risk increased to 4.1% from 1.2% in rural areas as compared to 4.8% from 2.5% in urban areas. Conclusions The CHD and CVD risk has increased over 20 years period in and around Delhi and the increase was more in rural population and women, traditionally considered to be at low risk.