WED-025 - Inflammatory and Cardiometabolic Biomarkers as Mediators and Suppressors of Racial Health Disparities in U.S. Adults

Brief Abstract Summary: Discover how racial differences in cardio-metabolic health reveal complex biological and social interactions. Using NHANES 1999–2010 data, this study quantifies Black–White disparities in diet quality, inflammation, glycemic control, and lipid biomarkers, testing whether diet, C-reactive protein (CRP), or hemoglobin A1c (HbA1c) mediate these gaps. Despite higher HbA1c and diabetes prevalence, non-Hispanic Black adults exhibited more favorable lipid profiles i.e., lower triglycerides and total-to-HDL cholesterol ratios than White adults. Mediation analysis showed that diet quality and inflammation did not explain these lipid differences, while glycemic control accounted for only 3–6% of the observed gap. Participants will gain insight into how biological pathways like glycemic regulation intersect with social determinants to shape racial disparities in cardiovascular risk, informing more targeted, equity-focused prevention strategies.

Detailed abstract description: Background
Non-Hispanic Black (NHB) adults experience disproportionate cardiovascular disease (CVD) risk yet often show more favorable lipid profiles than non-Hispanic White (NHW) adults. The extent to which socioeconomic and behavioral factors and potential biological mediators account for these disparities remains unclear.
Purpose
To quantify Black–White differences in diet quality, inflammation, glycemic control, and lipids in a nationally representative sample, and to test whether dietary quality, systemic inflammation, or glycemic control mediate racial differences in lipid outcomes.
Methods
We analyzed NHANES 1999–2010 adults ≥20years using survey-weighted generalized linear models. Outcomes: HEI-2015 score, log (CRP), TC/HDL ratio, triglycerides (log), HbA1c, and diabetes (quasibinomial; odds ratios). Models were fit in blocks: demographics (Model 1), + socioeconomic factors (Model 2), + behavioral/clinical covariates (Model 3: BMI, smoking, physical activity, sleep, diet). Multiple imputation addressed missingness. Counterfactual mediation quantified indirect effects of HEI-2015, log (CRP), and HbA1c on racial differences in TC/HDL and triglycerides.
Results
In fully adjusted models, NHB and Hispanic adults remained more likely to have diabetes than NHW adults (OR_NHB=1.48 [1.22–1.78]; OR Hispanic=1.67 [1.25–2.22]). HbA1c was higher among NHB (β=0.19) and Hispanic (β=0.15) adults (both p<.001). Despite this, NHB adults had more favorable lipids: lower TC/HDL (β=−0.42, p<.001) and triglycerides (β=−0.27, p<.001). CRP disparities attenuated and were nonsignificant after full adjustment. Mediation showed trivial, nonsignificant indirect effects via HEI-2015 and CRP for TC/HDL and triglycerides (e.g., HEI_TC/HDL: −0.005; 95% CI −0.023, 0.012). HbA1c significantly mediated a small share of racial differences (TC/HDL indirect=0.022; 95% CI 0.009, 0.036 ≈6% mediated; triglycerides indirect=0.012; 95% CI 0.005, 0.020 ≈3% mediated).
Conclusions/Implications
Black–White disparities in glycemic outcomes persist after extensive adjustment, whereas lipid profiles remain more favorable for NHB adults. Inflammation and diet quality do not explain these lipid differences, glycemic control accounts for only a modest fraction. Findings highlight the need for interventions that pair cardiometabolic risk factor management with upstream social determinants, and for research integrating biological and social pathways to clarify mechanisms driving persistent disparities.