New Delhi: Indians and other South Asians are twice as likely to develop heart diseases compared to those of European ancestry, a new US study has found.
The study by researchers from the Massachusetts General Hospital also noted that risk assessment calculators — which are used to guide decisions about preventing or treating heart diseases — fail to account for this increased risk of disease in South Asians, who account for a quarter of the world population.
For the study, the team evaluated data from the UK Biobank — a UK-based study that is investigating the contribution of genetic predisposition and environmental exposure to the development of diseases since 2006.
The researchers looked at data of people who did not have atherosclerotic cardiovascular disease when they enrolled in the study between 2006 and 2010. Atherosclerosis is the build-up of fats, cholesterol and other substances in and on the artery walls, which eventually could lead to heart attacks or strokes.
There were 8,124 participants of South Asian ancestry and 4,49,349 of European ancestry included in this analysis, who were followed for an average of 11 years.
Researchers compared the rates of developing cardiovascular disease, such as a heart attack, stroke, or undergoing a procedure to restore normal blood supply to the heart, among people of South Asian ancestry to those of European ancestry.
They found that 6.8 per cent of participants with South Asian ancestry had a cardiovascular disease event, while 4.4 per cent of those with European ancestry reported such events.
According to the study, published in the journal Circulation Monday, this represents an over two-fold higher risk for people of South Asian descent.
The researchers noted that the high risk factor was surprising since much of it remains unexplained.
“We were surprised by the magnitude of the increased risk — even within contemporary clinical practice, it was more than double — and how much of it remains unexplained by traditional clinical or lifestyle risk factors,” Amit V. Khera, a cardiologist at Massachusetts General Hospital in Boston, said in a statement.
Also read: Heart disease is leading cause of death in women. All-female-led Lancet group is stepping in
Clinical tools in US, Europe don’t capture increased risk factor of South Asians
The study also highlighted that clinical estimators used in the US or Europe to assess heart disease risk did not capture the increased risk factor of South Asians, identified by the study.
“Based on previous studies, we expected South Asians would have higher rates of heart disease — in fact, the American Heart Association now considers South Asian ethnicity a ‘risk enhancer’ beyond the standard risk calculator,” said Khera, who is also one of the senior study authors.
He also explained that these risk assessment calculators in the US do not capture the increased risk for South Asians, since no South Asians were included in the development of the tool.
“We need to dig deeper to better understand why South Asians are having heart attacks and strokes at higher rates even after accounting for these (lifestyle) risk factors,” said Aniruddh P. Patel, lead author of the study and a cardiology fellow at Massachusetts General Hospital.
Khera and colleagues have assembled a team of international investigators to aggregate data and expertise needed to develop new genetic risk estimators for South Asian individuals.
(Edited by Rachel John)
Also read: Higher apolipoprotein B shortens lifespan, increases risk of heart disease, finds Lancet study