[img_inline align=”right” src=”http://padnws01.mcmaster.ca/images/Yusuf edited.jpg” caption=”Dr. Salim Yusuf, professor of medicine at McMaster University and a cardiologist at Hamilton Health Sciences. File photo”]People who are native to South Asia experience heart attacks at an earlier age because of greater levels of heart attack risk factors such as smoking and diabetes earlier in life, according to a new study led by researchers at McMaster University's Population Health Research Institute (PHRI). The study will be published in the January 17 issue of the Journal of the American Medical Association.

The South Asian countries of India, Pakistan, Bangladesh, Sri Lanka, and Nepal account for about a quarter of the world's population and contribute the highest proportion of cardiovascular diseases compared with any other region globally. This has raised the possibility that South Asians exhibit a special susceptibility for heart attack that is not explained by traditional risk factors.

The average age of people in South Asia who experience a heart attack is 53 or 54, whereas in other parts of the world it is 58 or 59. Deaths related to cardiovascular disease occur five to 10 years earlier in South Asian countries than in Western countries, according to background information in the article.

Authors of the JAMA article include Dr. Salim Yusuf, professor of medicine at McMaster University and a cardiologist at Hamilton Health Sciences, as well as Shofiqul Islam and Sumathy Rangarajan of the PHRI.

The article notes that although risk factors are the same for South Asians as in other parts of the world, South Asians have greater levels of those risk factors at younger ages. The data suggests that lifestyle changes implemented early in life have the potential to reduce that risk.

Harmful factors that were more common in native South Asians than in individuals from other countries were a history of diabetes, current and former smoking, history of hypertension, psychosocial factors such as depression and stress at work or home, and a higher proportion of bad cholesterol compared to good cholesterol.

The prevalence of protective risk factors such as leisure time, physical activity, regular alcohol intake, and daily intake of fruits and vegetables, were markedly lower in South Asian study participants compared with those from other countries.

The study included 1,732 heart attack patients and 2,204 controls from 15 medical centres in five South Asian countries and 10,728 heart attack cases and 12,431 controls from other countries.