US South Asians need targeted programs to improve heart health, study says

U.S. South Asians—a predominately immigrant population with heritage from Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and/or Sri Lanka—have a higher risk for developing and dying from heart problems than East Asians or non-Hispanic white people. Pinpointing underlying causes has proved elusive, prompting Northwestern Medicine scientists to launch the largest cardiovascular-intervention trial for U.S. South Asians.

While research has tried to explain the multiple causes for South Asians' increased cardiovascular disease (CVD) risk, including risk factors like type 2 diabetes and less physical activity, relatively no work has assessed the success of attempts to change the heart health of one of the fastest-growing ethnic groups in the U.S.

Northwestern University scientists conducted the largest lifestyle-intervention trial for U.S. South Asians, underscoring a need to build a larger body of research to better represent the diverse and vastly underrepresented group.

The study was published in the journal JAMA Cardiology.

To the scientists' surprise, the 16-week targeted, culturally tailored lifestyle program failed to significantly reduce cardiovascular risk factors, such as blood pressure, cholesterol and blood sugar levels compared to the control group 12 months after the study began. But in self-reports, trial participants said they were eating healthier, moving more and feeling more confident in eating and exercise choices, indicating a shift in the right direction.

"This trial marks a significant step forward in understanding how we can effectively support South-Asian communities in managing their cardiovascular health," said Dr. Namratha Kandula, the study's lead investigator and a professor of medicine at Northwestern University Feinberg School of Medicine.

"While the results show that our intervention alone was not enough to significantly alter clinical risk factors, the positive changes in health behaviors are promising and pave the way for more refined approaches."

Kandula, also a Northwestern Medicine internal medicine physician, studies the way immigration can affect health disparities and has many affiliations across the University, including the Center for Diabetes and Metabolism, the Institute for Public Health and Medicine's Center for Community Health and the Robert J. Havey, MD Institute for Global Health's Center for Global Cardiovascular Health. She said she hopes the paper can be used as a model for others who are trying to engage diverse populations in clinical research.

The study was tailored to the unique cultural and linguistic needs of the South Asian community. The scientists worked with community partners, including community organizations, schools, public health officials and health coaches fluent in English, Gujarati, Hindi and Urdu, to deliver group sessions in familiar, accessible settings.

Between March 2018 and January 2022, 549 participants enrolled in the study and were randomly assigned to either a control group, which was mailed heart disease-prevention information each month, or the lifestyle-intervention group, in which participants attended tailored weekly group classes for 16 weeks.

Though the trial did not meaningfully change clinical heart-disease risk, Kandula said that could be explained by the timing of the coronavirus pandemic, the limited length of the trial and because many of the health challenges South Asians face are linked to environmental, not individual, factors.

"The trial was a way for people in the South Asian community to connect, create friendships and get support for their change in health behavior, which shows that improving heart health goes beyond the individual level, and that people need to be part of something bigger to sustain motivation and support," Kandula said.