Epidemiological Transition (in India)
- Lifestyles of populations across the world have changed dramatically in the 20th century as a result of advances in science and technology. Most human societies have moved from agrarian diets and active lifestyles to fast foods and sedentary habits.1-3
- Most pre-industrial societies are characterized by high rates of infant mortality, deaths primarily due to infection or malnutrition, and relatively short average life expectancy. Advances in sanitation, antibiotics, vaccines, and medications have reduced the burden of infectious disease and increased the lifespan.1
- As societies develop, infant mortality generally declines, the causes of death shifts, and average life expectancy increases. Rapid changes in lifestyle which includes improved nutrition, better hygiene, sedentary lifestyle, and increased tobacco use result in obesity, dyslipidemia, high blood pressure, and heart disease. These changes are collectively known as epidemiological transition.1
- Epidemiology involves the study of disease frequency and its determinants within the population. Cardiovascular epidemiology began in the 1930s as a result of changes observed in the causes of death. In the 1950s, several epidemiological studies were set in motion with the aim of clarifying the cause of CVD (cardiovascular disease).
- As a result of epidemiological transition the cause specific deaths from CVD has doubled to 36% of all deaths over the past two decades in India.4 In developed nations the rise in the burden of CVD occurred over several decades due to a long period of epidemiological transition.2, 4
- In India, perhaps because of the rapid pace of economic development, epidemiological changes have spanned a much shorter time. As a consequence, CVD has emerged as the leading cause of death all over India, with CAD (coronary artery disease) affecting Indians at least 5-6 years earlier than their western counterparts.3, 4
- Current estimates from different cross-sectional studies indicate the prevalence of CAD to be between 7-13% in urban and 2-7% in rural India (see Heart Disease India).
- The spiraling rates of modifiable risk factors for CAD across the spectrum of rural to urban segments of our population have been demonstrated by several studies across India.2
- In addition, migration and urbanization have resulted in an increase in the prevalence of diabetes and obesity.2, 3
1. Enas EA. How to Beat the Heart Disease Epidemic among South Asians: A Prevention and Management Guide for Asian Indians and their Doctors. Downers Grove: Advanced Heart Lipid Clinic USA; 2011.
2. Prabhakaran D, Shah P, Chaturvedi V, Ramakrishnan L, Manhapra A, Reddy KS. Cardiovascular risk factor prevalence among men in a large industry of northern India. Natl Med J India. Mar-Apr 2005;18(2):59-65.
3. Prabhakaran D, Yusuf S. Cardiovascular disease in India: lessons learnt & challenges ahead. Indian J Med Res. Nov 2010;132(5):529-530.
4. Thakur JS, Pala S, Sharma Y. Integrated non-communicable disease control program in northerpart of india: lessons from a demonstration project in low resource settings of adeveloping country. CVD Prevention and Control. 2010;4:193-199.