SAN FRANCISCO — Keeping a healthy heart in an effort to lower the risks of potentially deadly ailments like cardiovascular disease often means people work hard to watch their weight. A new study, however, finds that there’s an even bigger factor that can’t be controlled when it comes to predicting the risk of heart disease and other serious conditions: one’s race.

Researchers at the University of California, San Francisco examined 6,000 residents in some of the country’s biggest cities who identified as white, African-American, Chinese, or Hispanic Another 800-some residents from San Francisco and Chicago who identified as South Asian were also included in the study.

The participants were polled on their physical activity levels and their eating habits and their body mass index (BMI) levels were recorded and compared to norms for their respective races.

“While other studies have looked at race and cardio-metabolic risk, this is the first that looks at the relative differences between five races,” says senior author Dr. Alka Kanaya, professor of medicine, epidemiology and biostatistics in the Division of Internal Medicine at UCSF, in a university press release. “It’s also the first that compared risk between two different Asian populations.”

The findings were quite significant.

Participants who identified as South Asian were found to be twice as likely as whites to be at risk of heart disease, stroke, and diabetes — even when their BMI was considered normal. Hispanic Americans were 80 percent more likely than whites to “suffer from so-called cardio-metabolic abnormalities” that can cause the three conditions, while Chinese and African-American participants were 50 percent more likely to be at risk.

Individuals between the ages of 45 and 84 who had at least two risk factors for the conditions were classified as having cardio-metabolic abnormalities. Those risk factors include high blood pressure, elevated glucose, low levels of “good cholesterol” or HDL, and high triglyceride levels.

Researchers say doctors who are simply using weight as the rime factor when it comes to screening for the conditions may overlook the importance of race.

“These differences are not explained by differences in demographic, health behaviors or body fat location,” says first author Unjali Gujral, PhD, a postdoctoral fellow at the Global Diabetes Research Center at Emory University in Atlanta. “Clinicians using overweight/obesity as the main criteria for cardio-metabolic screening, as currently recommended by the U.S. Preventive Services Task Force, may fail to identify cardio-metabolic abnormalities in many patients from racial/ethnic minority groups.”

Kanaya adds that folks who registered as having normal weights shouldn’t go to extremes and push to lose more weight in an effort to improve their risk.

“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,” she says.

Normal BMI levels for each race examined in the study can be viewed in the university press release.

The study was published this week in the journal Annals of Internal Medicine.