Association between frailty index and erectile dysfunction: A cross-sectional study using NHANES 2001 to 2004 data.

The objective of this study was to examine the association between the frailty index (FI) and erectile dysfunction (ED) in the general US population. We utilized data from the National Health and Nutrition Examination Survey 2001 to 2004 on erectile function and the FI. ED was assessed via a self-reported questionnaire. The FI was calculated using a 49-item model and analyzed both as a continuous and a categorical variable. Participants were stratified into 3 groups: non-frail (FI ≤ 0.15), pre-frail (0.15 < FI ≤ 0.25), and frail (FI > 0.25). The association between the FI and ED was evaluated using weighted logistic regression across 3 models: model 1 (unadjusted), model 2 (adjusted for age, race, poverty-income ratio, marital status, and education level), and model 3 (further adjusted for additional potential covariates from model 2). Nonlinear associations were examined using restricted cubic spline, supplemented by subgroup analyses and interaction tests. Finally, receiver operating characteristic curve analysis was performed to assess diagnostic performance. This study included a total of 1372 participants, among whom 674 were diagnosed with ED. After adjusting for all covariates, a significant positive association was observed between the FI and ED (odds ratio [OR]: 1.09, 95% confidence interval [CI]: 1.06-1.19, P < .001). Using the non-frail group as reference, similar associations were found for both the pre-frail group (OR: 1.09, 95% CI: 1.03-1.16, P = .011; P for trend < .001) and frail group (OR: 1.22, 95% CI: 1.13-1.30, P < .001; P for trend < .001). Restricted cubic spline and smooth curve fitting demonstrated a linear relationship between FI and ED risk. Stratified analyses and interaction tests further confirmed the positive association between FI and ED prevalence. Receiver operating characteristic curve analysis (area under the curve = 0.662, 95% CI: 0.633-0.690) indicated that FI had moderate predictive accuracy for ED diagnosis. This study demonstrates a significant positive association between the FI and ED, with FI showing substantial predictive accuracy for ED. These findings suggest FI may serve as a valuable biomarker for ED prevention and clinical diagnosis.