County-Level Food Insecurity Linked to Increased Heart Failure Mortality Rates

Keerthi T. Gondi, MD

A nationwide analysis of county-level data is underlining the need for systemic change to reduce the future burden of heart failure on health systems and communities.

A university of Michigan-led analysis of National Vital Statistics System and USDA data, results of the study demonstrate counties with a food insecurity level greater than the national median experienced significantly greater heart failure mortality rates, with results also identifying density of grocery stores, access to stores among older adults, and Supplemental Nutrition Assistance Program (SNAP) participation rate as factors associated with heart failure mortality rates.

“Heart failure mortality is on the rise in populations that live in socioeconomic deprivation, and, importantly, we believe that nutrition plays a role in heart failure mortality, and food insecurity may be particularly detrimental in this population,” said lead investigator Keerthi T. Gondi, MD, an internal medicine resident at the University of Michigan Health System, in a statement from the American Heart Association. “We know that important relationships exist among food access and food affordability and heart health. This will have to be addressed in order to make changes to the burden of cardiovascular disease in populations that live in socioeconomic deprivation moving forward.”

Recent advances in therapy and management have left heart failure cardiologists and other cardiology care professionals more equipped than ever before. However, as the advances occur, the impact of social determinants of health on risk of adverse outcomes has become more apparent. With an interest in developing a more thorough understanding of how different social determinants of health might influence risk of negative outcomes in heart failure, Gondi and a team of colleagues conducted the current study with the specific intent of leveraging the National Vital Statistics System and USDA Food Environment Atlas to estimate the effect of various food environment factors on population-level heart failure mortality.

Using food environment and mortality data obtained from these sources, investigators designed their study to use linear regression to estimate the association between food environment and heart failure mortality rate. For the purpose of analysis, investigators used 2 county-level food environment indices as primary exposures of interest—food insecurity percentage (FI%) and food environment index (FEI), which is a scaled index (0–10, 10 best) incorporating FI% and access to healthy food. Other exposures of interest for the investigators’ analyses included SNAP participation rate, density of grocery stores, and access to stores for older adults.

From the aforementioned data sources, investigators obtained information related to 3147 counties for potential inclusion in their analyses. After exclusion of those with missing data for heart failure mortality of food environment indices, 2956 (93.9%) were included. Among the counties included, the mean county FI% was 13% and the mean FEI was 7.8.

Upon analysis, results indicated counties with an FI% above the national median had a significantly greater heart failure mortality rate than those with an FI% below the national median (30.7 vs 26.7 per 100,000; P <.001). When assessing similarities among counties with increased heart failure mortality, investigators found counties with increased heart failure mortality above the national median had a higher FI%, lower FEI, lower density of grocery stores, poorer access to stores among older adults, and lower SNAP participation rate (P <.001 for all).

In analyses adjusted for county demographic, socioeconomic, and health factors, investigators found a 1% decrease in FI% was associated with a 1.3% decrease in heart failure mortality rate (β=−1.3% per 1% decrease) and a 1-unit increase in FEI was associated with a 3.6% decrease in heart failure mortality rate (β=−3.6% per 1-unit increase in FEI). Investigators pointed out associations were stronger for heart failure-related mortality than non-heart failure cardiovascular disease mortality and all-cause mortality. Additionally, a stronger relationship was observed for the association of heart failure mortality and food environment in counties with the highest income inequity and poverty rate.

In an accompanying editorial, Jelani Grant, MD, and Chad Ndumele, MD, PhD, both of Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, underlined the importance of recognizing the impact of social determinants of health, including food insecurity, and their role in adverse outcomes when addressing cardiovascular disease.

“Within clinical environments, there is urgent need for providers caring for patients with HF to start integrating the evaluation of food security and environments into broader assessments of (social determinants of health) as part of clinical practice,” wrote the pair.

This study, “Health of the Food Environment Is Associated With Heart Failure Mortality in the United States,” was published in Circulation: Heart Failure.