Strong Heart Study (SHS)

In addition, the study found type 2 diabetes to be the strongest risk factor for cardiovascular disease in American Indians, providing a warning of higher future rates of cardiovascular disease in other populations with a high prevalence of diabetes. The study recently found diabetes and prediabetes in young adults to be independently associated with early adverse effects on heart structure and function.

SHS investigators are also trying to understand how genetics might affect blood cholesterol, blood pressure, and other factors related to heart disease. The study has shown that American Indians in the SHS have genetic risk factors related to heart disease that are both common to—and different from—other population groups. These results suggest that prevention and treatment efforts developed through the study of other population groups might not be as effective for American Indians. They have led to current efforts to better understand the unique set of genetic and environmental risk factors faced by American Indians.

The SHS is pioneering research to investigate the role of the environment—especially the presence of certain metals—in cardiovascular disease development. The SHS has found, for example, that arsenic and cadmium exposures are prospectively associated with higher cardiovascular risk. The SHS has also conducted brain magnetic resonance imaging (MRI) that showed that adverse cardiovascular events in the brain, such as stroke, are highly common in American Indian elders. Nearly 90 percent of these findings are subclinical, meaning they were not detected by routine health care or immediately recognized as stroke events; however, these subclinical strokes may contribute to cognitive or physical decline.

The NHLBI continues to encourage the use of anonymized SHS data and specimens to spur new scientific discovery in collaboration with the communities. The NHLBI invites researchers to utilize the valuable resources that have been collected since the study began in 1988. Learn more about utilizing SHS resources through the study website.

The SHFS was conducted to investigate the genetic contributions to cardiovascular disease and its risk factors. From 2001 to 2003, the SHFS recruited a total of 3,776 individuals from 94 extended families (about 1,200 members of extended families who were at least 15 years of age were recruited from each of the field centers), including 825 family members from the original SHS cohort. The SHFS completed two clinical exams. The original and family cohorts combined (over 7,600 participants) comprise the SHS. The SHS currently focuses on the continuation and expansion of the surveillance of the original and family cohorts. An updated data book and patient publication are planned to be available in 2026.

In addition to conducting valuable research, the study directly benefits the American Indian community. Participants in the study receive health exams that can lead to early detection of risk factors, heart disease and even cancer. Findings from the SHS are routinely shared with the communities to help support programs such as those that promote preventative health counseling, smoking cessation, and healthy eating, and physical activity.  The SHS has developed brochures about heart-healthy habits and made them available in waiting rooms, nutrition centers, and schools throughout the community.