A drop in income over six years was linked to a higher likelihood of CVD in a recent analysis of the ARIC (Atherosclerosis Risk in Communities) study, suggesting financial stress might be a predictor of worse heart health in the U.S.
Socioeconomic status has long been recognized as a risk factor for heart disease, Stephen Y. Wang, MPH, of Brigham and Women’s Hospital and Harvard Medical School, and co-authors wrote in JAMA Cardiology, with lower income tied to an increased risk of MI, heart failure and stroke. It makes sense—people who earn less and live in poorer communities have historically had worse access to healthcare, limited options for a nutritious diet and higher rates of psychosocial stress—but researchers remain unsure of how changes in income could affect those stats.
“In short, although low income is robustly associated with risk of CVD, causality remains debated,” Wang et al. wrote. “It is possible that low income is simply a marker of other characteristics that also predict worse health maintenance behaviors. For more robust causal inference, we need to observe whether changes in incomes are associated with CVD risk.”
Wang and colleagues pulled income data for 8,989 men and women from the ARIC database, which has been tracking the health of 15,792 people since 1987. They categorized patients according to changes in their household income, considering a primary endpoint of myocardial infarction, fatal coronary heart disease, heart failure or stroke over a follow-up period of 17 years.
During that period, 900 participants (10%) experienced an income drop of more than 50%; 6,284 (70%) saw relatively unchanged incomes; and 1,805 (20%) experienced a rise in income of more than 50%. After adjustment, a negative income change was associated with a 17% increased risk of CVD compared to no income change, and a positive income change was linked to a 14% decrease in the likelihood of CVD compared to no income change.
Wang et al. noted a handful of mechanisms that could be behind the heightened CVD risk, including the fact that an unanticipated drop in income could push people into poor health habits like smoking or consuming more alcohol. Financial stress and worry can also predict depression, which in turn is a risk factor for coronary artery disease.
Income drops can also result in a loss of health coverage, the authors said, though they didn’t find that in their own study.
“We attempted to elucidate some of these mechanisms by adjusting for health insurance status and health behaviors after income change,” the team wrote. “However, our hazard ratios did not change significantly from the original model; hence, there must be other factors, beyond health behaviors and health insurance coverage, that account for these associations.”
In a related editorial, Edward P. Havranek, MD, of Denver Health and the University of Colorado School of Medicine, said Wang and colleagues’ work can facilitate a larger discussion about how physicians should respond to societal problems that cause illness. Many in the medical field are quick to take strong stands on issues like smoking and obesity, he said, but shy away from more political discussions.
“Our path has been less clear when the problems veer more toward the political,” Havranek wrote. “However, the choice between plunging into political discussions and avoiding the discussions altogether is a false one. We as a profession have a responsibility to promote full understanding of the health effects of the social structure we as a society have chosen. Results, such as those put forward by Wang et al., are clearly a step in that direction.”
After graduating from Indiana University-Bloomington with a bachelor’s in journalism, Anicka joined TriMed’s Chicago team in 2017 covering cardiology. Close to her heart is long-form journalism, Pilot G-2 pens, dark chocolate and her dog Harper Lee.