Largest-ever risk factor study in India identifies cardiovascular disease epidemic causes

The Indian Heart Watch (IHW) study has revealed the truth behind the prevalence, awareness, treatment and control of key risk factors that are driving the country's growing cardiovascular disease (CVD) epidemic, in a first-of-a-kind presentation of data at the World Congress of Cardiology today.

The study assessed the prevalence of different "lifestyle" and biological CVD risk factors across the country – and results show that these risk factors are now at higher levels in India than in developed countries and regions such as the USA and Western Europe.

Seventy-nine per cent of men and 83 per cent of women were found to be physically inactive, while 51 per cent of men and 48 per cent of women were found to have high fat diets. Some 60 per cent of men and 57 per cent of women were found to have a low intake of fruit and vegetables, while 12 per cent of men and 0.5 per cent of women smoke.

Moreover, the prevalence of biological and metabolic risk factors was also found to be high. Overweight and obesity was reported in 41 per cent of men and 45 per cent of women. High blood pressure was reported in 33 per cent of men and 30 per cent of women, while high cholesterol was found in one-quarter of all men and women. Diabetes (and or metabolic syndrome) was also reported in 34 per cent of men and 37 per cent of women.

"India has the dubious distinction of being known as the coronary and diabetes capital of the world," said Prof. Prakash Deedwania, University of California, San Francisco, USA. "These results show why - and must prompt the government to develop public health strategies that will change lifestyles, if these risk factors are to be controlled."

The Coronary Heart Disease Epidemic Few people alive today are old enough to remember the beginning of the coronary heart disease (CHD) epidemic in the 1920s and 1930s, when physicians in the U.S. and U.K. began sounding alarm bells that an uncommon disease was rapidly becoming the leading cause of death. By the 1950s, their predictions had come true. A decade later, a new generation of physicians replaced their predecessors and began to doubt that heart attacks had ever been rare. Gradually, the idea that the disease was once uncommon faded from the public consciousness, and heart attacks were seen as an eternal plague of humankind, avoided only by dying of something else first.

According to U.S. National Vital Statistics records beginning in 1900, CHD was rarely given as the cause of death by physicians until after 1930. The following graph is from The Great Cholesterol Con, by Anthony Colpo, which I highly recommend.

The relevant line for CHD deaths begins in the lower left-hand part of the graph. Other types of heart disease, such as heart failure due to cardiomyopathy, were fairly common and well recognized at the time. These data are highly susceptible to bias because they depend on the physician's perception of the cause of death, and are not adjusted for the mean age of the population. In other words, if a diagnosis of CHD wasn't "popular" in 1920, its prevalence could have been underestimated. The invention of new technologies such as the electrocardiogram facilitated diagnosis. Changes in diagnostic criteria also affected the data; you can see them as discontinuities in 1948, 1968 and 1979. For these reasons, the trend above isn't a serious challenge to the idea that CHD has always been a common cause of death in humans who reach a certain age.