Emergence of chronic obstructive pulmonary disease as an epidemic in India.

Chronic obstructive pulmonary disease (COPD), hitherto underdiagnosed in India, is now recognized in 4-10 per cent of adult male population of India and several other Asian countries. The Regional COPD Working Group for 12 Asia Pacific Countries and Regions used a COPD prevalence model and estimated an overall prevalence rate of 6.3 per cent with a range from 3.5 to 6.7 per cent. The smoking associations with COPD were high from most countries i.e., 2.65 in India, 2.57 in China and 2.12 in Japan. In a large, multicentric study from India, the population prevalence of COPD was 4.1 per cent of 35295 subjects with a male to female ratio of 1.56:1. Almost all forms of smoking products such as cigarettes and 'bidis' used in different States were found to be significantly associated with COPD. In non-smokers, especially women, exposures to indoor air pollution from domestic combustion of solid fuels was an important factor. More significantly the exposure to environmental tobacco smoke (ETS) was an established cause for COPD. The odds ratio for risk from ETS exposure in non-smokers (1.535) was on significant during both the childhood and the adulthood. On an average, an Indian COPD patient spent about 15 per cent of his income on smoking products and up to 30 per cent on disease management. Tobacco smoking was also the most frequent cause of chronic cor pulmonale which occurred as a long term complication of COPD both amongst men and women.