A family history of heart disease can raise your risk of developing it but so, too, can where your family came from: New research found that, even if they're a normal weight, South Asian Americans are twice as likely as white people to have heart disease risk factors. Americans of Hispanic descent were 83 percent more likely to to face a higher risk and Chinese and black Americans had about a 50 percent higher risk than white people.
To figure this out, researchers from Emory University and the University of California San Francisco analyzed data from two studies whose participants ranged in age from 45 to 84. The first study included 803 South Asian residents of the Chicago and San Francisco Bay areas, and who traced their ancestry to Bangladesh, India, Nepal, Pakistan, or Sri Lanka. (To be eligible for that study, people had to have three or more grandparents born in one of these countries and be able to speak and read English, Hindi, or Urdu.) The other study included about 6,000 people from the Baltimore, Chicago, Los Angeles, Minneapolis-St. Paul, New York, and Winston-Salem areas. The people in this larger group identified as either black, Chinese, Latinx, or white.
The researchers looked at participants' body mass index (BMI) and pared the groups down to those who were considered normal weight by the World Health Organization, which is a BMI of 18.5 to 24.9 for white, black, and Latinx people, and 18.5 to 22.9 for Chinese and South Asian people.
Next they considered how many of the normal-weight people had any of these four risk factors for heart disease, stroke, and diabetes: high blood pressure, high fasting blood sugar levels, low HDL, aka "good" cholesterol, and high triglycerides, a fat found in blood. If people had two or more of them, they were considered to have cardio-metabolic abnormalities, or a higher risk of heart-related health problems. Participants also filled out questionnaires about their activity levels and eating habits. That's how they determined the relative risk for each of the four communities of color. The authors noted that the differences could not be explained by body fat location, demographics, or health behaviors, including smoking and caloric intake. (Overall, 29 percent of normal-weight people in the study had at least two risk factors.)
Interestingly, they found that the risk factor combinations were slightly different between groups. Among people who had at least two of the four risk factors, the most common combo in white people was low HDL and high blood pressure (40 percent). But in all other groups it was low HDL and high blood sugar (48.7 percent in South Asians, 37.3 percent in Chinese, 36.4 percent in black people, and 37.9 percent in Latinx).
Finally, as a depressing little exercise, they estimated the necessary BMI for each group of people of color if they were to equal the same number of heart-health risk factors as overweight white people (who had a BMI of 25 and above). They calculated that black people would hit it with a BMI of 22.9, Latinx people with a BMI of 21.5, Chinese people with a BMI of 20.9, and South Asian people with a BMI of 19.6. (A 19.6 is the equivalent of 118 pounds for a 5-foot-5 woman.) As in, a person of color could be thinner than a white person and still have the same amount of heart health risk factors. The study, published in Annals of Internal Medicine, was funded by the National Institutes of Health and the National Heart, Lung and Blood Institute.
The American Heart Association notes that black Americans tend to have more severe high blood pressure and thereby higher heart disease risk than white people, but Mexican Americans, Native Americans, native Hawaiians, and some Asian Americans also face an elevated risk, partly because of higher rates of diabetes and obesity.
Senior author Alka Kanaya, a professor of medicine, epidemiology, and biostatistics at UC San Francisco said in a release that it's the first study to look at the relative difference in heart risks between five different races, and also the first to compare the risk between two different Asian populations. Her co-author Unjali Gujral, a postdoctoral fellow at Emory University's Global Diabetes Research Center, pointed out that doctors may be missing heart risks in patients of color, especially if they use weight as the main criteria.
Kanaya added: "We hope the results will enable patients and their health care providers to see that race/ethnicity alone may be a risk factor for cardio-metabolic health in minority Americans."