Investigating the impact of ALI on erectile dysfunction in American men: a cross-sectional study using NHANES data

Inflammation and nutritional status may contribute to erectile dysfunction (ED), but the association between the Advanced Lung Cancer Inflammation Index (ALI) and ED has not been well characterized.

To examine the association between ALI and ED in US men and to explore the within-sample discriminatory ability of ALI for ED status.

We performed a cross-sectional analysis of 3735 men from the National Health and Nutrition Examination Survey (NHANES) 2001-2004. ALI was calculated from body mass index, serum albumin, and the neutrophil-to-lymphocyte ratio. Survey-weighted multivariable logistic regression was used to assess the association between ALI and ED, with subgroup analyses to explore potential effect modification. Nonlinearity was evaluated using smoothed curve fitting and a 2-piece linear regression model. Within-sample discrimination was descriptively assessed using survey-weighted receiver operating characteristic curve analysis in randomly split subsets from the same dataset.

Outcomes were the association between ALI and ED and the within-sample discriminatory ability of ALI for ED status.

The weighted prevalence of ED was 28.2%. Higher ALI was associated with lower odds of ED. In continuous analyses, ALI remained inversely associated with ED after multivariable adjustment (odds ratio [OR] = 0.33, 95% confidence interval [CI]: 0.21-0.52; P < .001), and the association persisted in further adjusted models (OR = 0.38, 95% CI: 0.19-0.74; P = .014; OR = 0.46, 95% CI: 0.25-0.84; P = .033). A nonlinear association was observed, with an inflection point at ln-ALI = 1.912. Below this threshold, ln-ALI was inversely associated with ED (OR = 0.21, 95% CI: 0.11-0.39; P < .001), whereas no statistically significant association was observed above the threshold (OR = 2.51, 95% CI: 0.72-8.80; P = .150). The area under the curve was 0.85 (95% CI: 0.83-0.87) in the training subset and 0.83 (95% CI: 0.81-0.86) in the validation subset.

ALI may serve as an accessible correlate of ED status in population-based settings; however, its predictive utility requires longitudinal validation.

Strengths include the use of a nationally representative sample and survey-weighted analyses incorporating nonlinear modeling and discrimination assessment. Limitations include the cross-sectional design, self-reported ED, possible residual confounding, and the use of NHANES 2001-2004 data, which may limit direct applicability to contemporary populations.

Higher ALI was associated with lower odds of ED among US men. The observed receiver operating characteristic findings reflect within-sample discrimination only and require cautious interpretation.