U.S. South Asians — a predominantly 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 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 this diverse and vastly underrepresented group.
The study was published today 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. However, in self-reports, trial participants said they were eating healthier, moving more and feeling more confident in their 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 studies how immigration can affect health disparities and holds many affiliations across Northwestern University. She hopes this paper can serve as a model for others trying to engage diverse populations in clinical research.
The study was tailored to meet the unique cultural and linguistic needs of the South Asian community. The scientists collaborated with community partners including organizations, schools, public health officials and health coaches fluent in English, Gujarati, Hindi and Urdu to deliver group sessions in familiar settings.
Between March 2018 and January 2022, 549 participants enrolled in the study and were randomly assigned either to a control group that received monthly mailed heart disease-prevention information or to a lifestyle-intervention group that attended tailored weekly group classes for 16 weeks.
Though the trial did not meaningfully change clinical heart-disease risk factors, Kandula suggested this could be due to various reasons including timing during the coronavirus pandemic or environmental challenges faced by South Asians rather than individual ones.
“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,” Kandula said. “This shows that improving heart health goes beyond individual efforts; people need to be part of something bigger to sustain motivation and support.”
The study was supported by grants from several institutes within National Institutes of Health: National Heart Lung Blood Institute (R01HL132978), (R01HL132978-05S1), (K24HL155897) along with National Center Advancing Translational Sciences (UL1TR001422).