Addressing Healthcare Disparities Through Research: A Spotlight on NHLBI’s Strong Heart Study

Heart disease disproportionally effects American Indians and is double that of the general US population. The Strong Heart Study has been examining why there is such disparities in health in this population for more than 30 years. Lessons learned from the Strong Heart Study are being applied to improve the health of the American Indians and other underserved communities across the nation.

Since 1988, MedStar Health Research Institute has been one of the three main collaborating institutions of the Strong Heart Study. Funded by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH), the Strong Heart Study is the largest and longest study of heart disease among American Indians. It includes more than 7,600 participants representing 12 communities across three main field centers in Arizona, Oklahoma, and the Dakotas. Analysis of more than 30 years of data has allowed MHRI investigators and collaborators to better understand how cardiovascular disease risk factors vary among American Indians, offering insights into how clinicians and public health groups might evolve and adapt disease prevention and treatment approaches to be more equitable and impactful across populations. 

Some of the key findings produced by this study include:

• Heart and vascular disease among American Indians has increased over the past 50 years and is now double that of the general U.S. population.

• While recent data shows slow improvement, there is still work to be done to reduce rates among this population, including continued investment in public health programs to raise awareness about lifestyle and other risk factors. 

• Known cardiovascular disease risk factors, including high blood pressure, cholesterol, and smoking are all important in American Indians, even though levels may be lower than in other populations. Strong Heart data showed that having type 2 diabetes is the strongest risk factor for cardiovascular disease in American Indians and did so before this was recognized in other groups. 
• Genetic risk factors have also been identified among American Indians, some of which mirror risks in other populations and others which have been discovered first in the Strong Heart Study, underlining the importance of genetic studies in diverse populations. 
• Environmental factors may also play a role in cardiovascular disease development, with research finding that exposures to arsenic and cadmium, at levels thought previously to be safe, are prospectively associated with higher risk.

As one of our longest continuous research initiatives, the Strong Heart Study is one of the Institute’s foundational efforts into understanding the root causes of health disparities among underserved populations. We know that addressing health disparities involves understanding the needs of the community beyond those typically addressed in the medical care system, such as housing, nutrition, transportation, and culture. In addition to conducting important data collections about cardiovascular disease, the Strong Heart team has worked to develop strong, trusted relationships within tribal communities that honor each participant’s culture. 

Using community ties to fight COVID-19

Strong Heart program leaders have stepped up to help American Indian communities fight the COVID-19 pandemic. In partnership with the participating tribal communities, the Strong Heart field center teams have pivoted their efforts to prevent the spread of the virus among local tribes. The staff has volunteered to help distribute masks and educational materials, and most recently, collaborated with local public health officials on encouraging uptake of the COVID-19 vaccine among younger tribal members. 

Investigators in the Strong Heart Study have also recently partnered with the NHLBI-funded Collaborative Cohort of Cohorts for COVID-19 Research (C4R), an observational study of more than 50,000 individuals nationwide to determine factors that predict disease severity and long-term health impacts of COVID-19.