Hemoglobin-to-Red Blood Cell Distribution Width Ratio and Erectile Dysfunction Among U.S. Adults: A Moderated Mediation Analysis of Body Roundness Index

This study investigates the association between the hemoglobin-to-red blood cell distribution width ratio (HRR) and erectile dysfunction (ED), a prevalent male sexual health concern. Analyzing data from 2,197 participants in the National Health and Nutrition Examination Survey (2001–2004), we employed logistic regression models and restricted cubic spline analysis to examine this relationship while conducting comprehensive sensitivity and subgroup analyses. Of the participants, 725 individuals reported ED history. Regression analysis revealed a significant inverse relationship between HRR levels and ED likelihood, with fully adjusted models showing a 69% reduced ED risk per HRR unit increase (odds ratio [ OR ] = 0.31, 95% confidence interval [CI] = [0.12, 0.77], p = .016). Tertile analysis demonstrated progressive ED risk reduction across ascending HRR categories in all models: Model 1 ( OR = 0.29, 95% CI = [0.23, 0.37], p < .001), Model 2 ( OR = 0.58, 95% CI = [0.43, 0.82], p = .003), and Model 3 ( OR = 0.66, 95% CI = [0.45, 0.97], p = .035). Restricted cubic spline analysis confirmed linear association patterns without significant nonlinearity ( p > .05). Sensitivity analyses reinforced HRR’s consistent negative correlation with ED risk, whereas subgroup analyses revealed stable associations across demographic strata without significant interaction effects. Our findings identify reduced HRR as an independent risk factor for ED, suggesting its potential utility as a clinical biomarker for early ED detection and prevention strategies. This novel hematological parameter could enhance risk stratification and inform interventions to mitigate disease progression and recurrence, potentially improving therapeutic outcomes in male sexual health management.