What is the goal of the ARIC study?
The goal of the NHLBI’s Atherosclerosis Risk in Communities (ARIC) study is to investigate the causes of atherosclerosis, a disease marked by plaque build-up in the arteries, and the clinical outcomes in adults from four U.S. communities. Another goal of the study is to measure how cardiovascular risk factors, medical care, and outcomes vary by race, sex, place, and time. To meet these goals, the study includes a cohort and community surveillance approach.
- ARIC has enrolled approximately 16,000 adults from four U.S. communities and has monitored them for 30 years.
- The study helped assess rates of heart attack, hospitalizations from heart failure, and deaths due to heart disease in over 400,000 adults.
- Findings have shaped clinical guidelines that doctors now use to treat coronary heart disease, diabetes, stroke, and chronic kidney disease.
- ARIC has led to more than 1,800 published scientific articles.
What are the key findings of the ARIC study?
The ARIC study has led to many discoveries that have increased our understanding of the causes of atherosclerosis and cardiovascular disease. These discoveries have shaped evidence-based clinical practice guidelines for coronary heart disease, diabetes, stroke, and chronic kidney disease. And, for 25 years ARIC community surveillance data has provided rigorously-validated data on the incidence and fatality rate of coronary heart disease in U.S. populations.
The following are examples of key ARIC findings:
- This was the first U.S. population-based study to establish carotid intima-media thickness (IMT) to be a marker of subclinical, that is having no detectable signs and symptoms, of atherosclerosis, which is associated with adverse cardiovascular disease outcomes. The study also documented that the considering carotid IMT can improve cardiovascular disease prognosis.
The study provided prospective data on the relationship of cardiovascular disease in African Americans and novel risk factors, such as lipoprotein A levels, vitamin D levels, and fat distribution.
The study offered information on novel risk factors for heart failure, allowing investigators to create a useful heart failure prediction model and a stroke risk prediction model, one of the few that included African Americans.
ARIC documented for the first time the prevalence of a set of ideal cardiovascular disease health metrics and provided evidence that the number of health metrics relates to cardiovascular disease rates. The American Heart Association has since labeled this set of health metrics as Life’s Simple Seven.
The study played a major role in identifying PCSK9 gene mutations that determine low cholesterol levels and decreased coronary heart disease risk.
ARIC found that high levels of inflammatory markers are associated with a higher risk of diabetes, shaped discovery that has shaped our current understanding of how inflammation causes diabetes.
The study produced some of the first evidence that lifestyle factors contribute to the risk of venous thromboembolism, a blood clot that starts in a vein, offering possible keys to prevention.
How is the ARIC study conducted?
The ARIC study consists of two components: community surveillance and a cohort. Participants were recruited from four ARIC study communities: Forsyth County, North Carolina; Jackson, Mississippi; eight northern suburbs of Minneapolis, Minnesota; and Washington County, Maryland. The community surveillance component was conducted from 1987-2014 and was designed to determine the long-term trends in hospitalized heart attack and coronary heart disease deaths in over 400,000 adults, aged 35 to 84 years, residing in the four communities. In 2006, surveillance of hospitalizations for heart failure for men and women aged 55 years and older was added.
The cohort component was created to build on results from the community surveillance component. The data were validated using standard methods involved in cohort studies that follow a group over a long period of time, and by providing additional information, such as risk factors and out-of-hospital medical care. The cohort study was initiated in 1985, and investigators recruited 15,792 black and white adults aged 45 to 64 years, who completed four clinic examinations, conducted three years apart, in 1987-1989, 1990-1992, 1993-1995, and 1996-1998. A fifth examination was conducted in 2011-2013. Follow-up conversations also occur semi-annually by telephone to maintain contact and to assess the health status of the cohort.