Socioeconomic inequalities in cardiometabolic health among United States adults using NHANES data

To quantify socioeconomic inequalities among U.S. adults using NHANES 2021–2023 data, applying advanced inequality metrics to capture disparities in the post-pandemic period. We analyzed adults from NHANES 2021–2023 with complete socioeconomic and health outcome data. Socioeconomic status (SES) was assessed using the Poverty Income Ratio (PIR; continuous) and education. Outcomes included obesity (BMI ≥ 30 kg/m²), central obesity (waist circumference ≥ 102 cm in men/≥88 cm in women), hypertension (SBP ≥ 130 mmHg or DBP ≥ 80 mmHg), HDL cholesterol (men < 40 mg/dL; women < 50 mg/dL), and diabetes (HbA1c ≥ 6.5%). Inequalities were quantified using the Relative Index of Inequality (RII) based on ridit-transformed SES variables in survey-weighted Poisson regression models, and the Concentration Index (CI) by PIR. The analytic sample included 6,878 adults. Prevalence estimates were: central obesity 55.6%, obesity 39.8%, hypertension 37.3%, low HDL 23.7%, and diabetes 9.9%. Strong socioeconomic gradients were observed. PIR-based RII values indicated lower risks at higher SES: obesity 0.76, central obesity 0.82, hypertension 0.73, low HDL 0.52, and diabetes 0.33. Education-based RIIs revealed even steeper inequalities, especially for diabetes (0.30) and low HDL (0.44). All CI values were negative (e.g., diabetes − 0.154), confirming disproportionate concentration of adverse outcomes among disadvantaged groups. Measured and laboratory-defined cardiometabolic abnormalities remain highly prevalent and strongly socially patterned in the post-pandemic U.S. Consistent pro-rich inequalities highlight the need for equity-oriented prevention and monitoring strategies, while underscoring the importance of interpreting laboratory-based outcomes in light of potential underestimation among higher-SES groups with well-controlled disease.