Cardiometabolic health of low- and higher-income adults in the United States, 2009-2023.

BACKGROUND

Cardiometabolic risk factors are major contributors to premature mortality in the United States. Little is known about recent changes in the cardiometabolic health of US adults by income level, particularly after the COVID-19 pandemic.

OBJECTIVE

To assess changes in the cardiometabolic health of US adults from 2009 to August 2023 by income level, and to evaluate pandemic-related shifts.

METHODS

We conducted a serial cross-sectional analysis of National Health and Nutrition Examination Survey participants aged ≥ 18 years (2009-2010 to August 2021-August 2023). Low-income was defined as ≤ 200% of the federal poverty level. We evaluated changes in the age- and sex-adjusted prevalence, treatment, and control of hypertension, diabetes, and high cholesterol, and the prevalence of obesity and smoking, among low- and higher-income adults. Linear regression models estimated pandemic-associated shifts.

RESULTS

Among 62,108 adults (mean age 46.3 years; 51.7% female), the prevalence of hypertension or high cholesterol did not change in either income group. Obesity prevalence rose among low-income adults (37.3% to 42.1%; absolute change +4.8 pp [95% CI, 1.1, 8.5]). Diabetes prevalence increased in both groups (low-income: +5.1 pp [1.4, 8.8]; higher-income: +2.5 pp [0.7, 4.3]), but remained higher among low-income adults (17.6% vs 12.4%; absolute difference +5.2 pp [1.6, 8.8]). While diabetes treatment did not change, an income-related gap in diabetes control emerged: by August 2021-August 2023, 43.0% of low-income adults achieved glycemic control compared to 52.8% of higher-income adults (absolute difference -9.8 pp [-17.5, -2.1]), coinciding with a greater-than-expected decline in diabetes control among low-income adults in the wake of the pandemic (level shift -8.7 pp [-16.7, -0.6]). The income-related gap in hypertension treatment in 2009-2010 had closed by August 2021-August 2023, following a greater-than-expected increase in treatment among low-income adults after the pandemic (level shift +7.8 pp [1.8, 13.8]). High cholesterol treatment and control improved in both groups, with no income-related differences. Smoking declined for both low-income (30.2% to 22.8%, absolute change -7.4 pp [-12.0, -2.8]) and higher-income (15.0% to 10.3%, absolute change -4.7 pp [-7.1, -2.3]) adults, but remained more than two-fold higher in the low-income group.

CONCLUSIONS

Between 2009 and August 2023, there was no improvement in the prevalence of hypertension or high cholesterol. Obesity and diabetes prevalence rose among low-income adults and a new income-related gap in diabetes control emerged, coinciding with a greater-than-expected decline in glycemic control among low-income adults after the pandemic. Targeted efforts are needed to improve risk factor prevention, strengthen glycemic control in low-income populations, and address persistent income-related disparities in cardiometabolic health.