Jun. 01 2020

AHA Statement Highlights Heart Risks to American Indians

Columbia Mailman School environmental health sciences professor Ana Navas-Acien is one of a group of researchers and clinicians who authored a scientific statement in the journal Circulation about cardiovascular health in American Indians and Alaska Natives. Their American Heart Association statement summarizes cardiovascular risk factors these groups face, highlighting the specific risk of diabetes. It is the first time an AHA statement has recognized the importance of exposure to toxic metals as risk factors for cardiovascular disease. Cardiovascular disease is the leading cause of death in American Indians and Alaskan Natives over the past 50 years, and its prevalence is rising.

For the last 12 years, Navas-Acien, a physician and epidemiologist, has helped lead environmental cardiovascular research in the Strong Heart Study among American Indian populations in four states, which found that long-term exposure to arsenic and cadmium was associated with increased incidence of coronary heart disease and stroke over 20 years of follow-up, with higher risk among participants with diabetes. Arsenic and cadmium were also related to a higher incidence of peripheral arterial disease, left ventricular hypertrophy, and diabetes. Elevated exposure to arsenic reflects groundwater contamination, common in small water systems in the Midwest and Southwest and in private wells, which are unregulated.

The authors say these findings support initiatives to install and maintain water systems in affected communities such as the Mni Wiconi Project, which brought safe water to the Oglala Sioux community. Many tribal members, however, rely on private wells. The Strong Heart Water Study for Private Wells is a multilevel participatory study evaluating the efficacy of a water filter and educational intervention in tribal communities in South Dakota. Other strategies might be needed, such as improving diet to mitigate the health effects of environmental exposures or removing persistent metals with chelating agents.

“American Indians and Alaska Natives are disproportionally affected by exposure to environmental chemicals including toxic metals, which has contributed to cardiovascular disease,” says Navas-Acien. “These disproportionate exposures are a result of extensive mining and natural resources exploitation, naturally occurring contamination, and scarce resources for effective mitigation.”

The AMA report is based on a review of data from PubMed/MEDLINE academic studies, the Centers for Disease Control and Prevention, and the annual Heart Disease and Stroke Statistics report from the American Heart Association. However, the authors note that underreporting of American Indian and Alaska Native race could underestimate the extent of cardiovascular disease in this population. Marie Gross, RN, MPH, member of the Cheyenne River Sioux Tribe, author of the statement, and long-term collaborator of Navas-Acien indicates “sharing the information and recognizing the burden and risk factors for cardiovascular disease in American Indians and Alaska Natives is critical to develop effective interventions and improve health outcomes.”

The authors conclude that prevention and treatment of cardiovascular disease in American Indians and Alaska Natives should focus on control of risk factors and community-based interventions that address social determinants of health. American Indians and Alaska Natives are the racial and ethnic group with the highest poverty level in the United States; a quarter of American Indians live below the federal poverty line. These conditions are further exacerbated by physician bias experiences of discrimination and microaggressions in the healthcare setting, and environmental inequalities. Specific programs to address diabetes risk include physical activity and weight loss; aggressive control of risk factors such as LDL cholesterol, hypertension, and albuminuria; promotion of tobacco cessation; and toxic metal mitigation.

The report was led by Khadijah Breathett, UA College of Medicine, Tucson and eight other co-authors, on behalf of the American Heart Association Council on Epidemiology and Prevention; Council on Quality of Care and Outcomes Research; Council on Cardiovascular and Stroke Nursing; Council on Clinical Cardiology; and Council on Lifestyle and Cardiometabolic Health.