It’s a surprising discovery in the cardiac health world: South Asians get heart disease earlier, have higher rates of heart disease and die more of heart problems than Caucasians.
More than 3 million Americans claim South Asian heritage -- people whose families came from Bangladesh, Bhutan, India, the Maldives, Nepal, Pakistan and Sri Lanka. Worldwide, they make up a quarter of the population, according to the American Heart Association.
The AHA has put out a scientific statement, which gathers together information from decades of research. According to the research, it comes down to biology, higher rates of diabetes and of high blood pressure, higher body mass index and higher levels of cholesterol and fats in South Asians' blood.
Let’s dive into a few of these.
Biology/diabetes: This is the biggest risk factor difference. South Asians are twice as likely to develop diabetes and have abnormal sugar levels. Type 2 diabetes is a risk factor for coronary disease and a predictor for having heart issues and diabetics have a two- to three-fold increased risk of cardiovascular death as high blood sugar affects the blood vessels.
Cholesterol levels: South Asians in the U.S. have higher levels of triglycerides (fats) and “bad” cholesterol (LDL-C), with lower levels of (HDL-C) or "good" cholesterol. That’s genetic.
Hypertension: High blood pressure is another risk factor for developing heart disease -- and 43 percent of men and 35 percent of women of South Asian descent are hypertensive in the U.S.
Inflammation: Research has shown that those with higher levels of inflammatory molecules (homocysteine, high-sensitivity C reactive protein, etc.) are at a higher risk for heart disease. South Asians have higher levels of these inflammatory markers circulating in their blood, which indicates more overall inflammation in their bodies.
Diet: The typical South Asian diet has a high percentage of carbohydrates and saturated fats. Lentils, vegetables, rice, meats and breads are the mainstays, but a lot of South Asians are vegetarians due to religious or culture reasons. That means an absence of lean meats and an increase of fats and carbohydrates in their diets.
Is there a way to identify high-risk patients at particularly high risk?
Yes. A simple, quick computed tomography (CT) scan to look at the blood vessels of the heart is a great way to identify patients at the highest risk. Several studies have shown that South Asians have higher amounts of calcium, blockages in the coronary arteries -- blood vessels that supply the heart -- and they tend to be in multiple vessels. Several decades of research tell us that higher amounts of calcium in the blood vessels that supply our heart mean a higher likelihood of heart disease and heart attacks. South Asians older than 60 have the highest coronary artery calcium burden (scores greater than 100) of any ethnic group.
What do you do about those blockages?
One option is a procedure that places a stent -- a tiny scaffolding inside a blood vessel that holds it open. The good news? The outcomes in South Asians are similar to other races. But if it requires more than a stent? Bad news: if South Asians require coronary bypass surgery, they have poorer outcomes.
So what does all this mean, from a practical standpoint?
You have to take on the risks themselves. The AHA recommends tailored interventions including education, promoting a healthy diet, exercise and talking with doctors about their risk factors.
Sunny Intwala, M.D., is a third-year cardiology fellow affiliated with Boston University School of Medicine and a clinical exercise physiologist who works in the ABC News Medical Unit.