Association between systemic immune-inflammation index and urinary incontinence: Evidence from the National Health and Nutrition Examination Survey

Abstract

Objective

This study examined the association between the systemic immune-inflammation index and urinary incontinence subtypes using data from National Health and Nutrition Examination Survey 2007–2016.

Methods

This cross-sectional study included 21,569 adults. Systemic immune-inflammation index was calculated and log-transformed. Survey-weighted logistic regression analyses, smoothed curve fitting, exploratory threshold analyses, and subgroup analyses stratified by demographic and clinical characteristics were conducted to evaluate its associations with stress urinary incontinence, urgency urinary incontinence, and mixed urinary incontinence.

Results

Higher log₁₀ systemic immune-inflammation index levels were significantly associated with an increased prevalence of stress urinary incontinence. Associations with urgency urinary incontinence and mixed urinary incontinence were weaker, and quartile trends were not statistically significant. Smoothed curve fitting demonstrated monotonic increases for stress urinary incontinence and mixed urinary incontinence, whereas a nonlinear pattern was observed for urgency urinary incontinence, suggesting a potential threshold at a log₁₀ systemic immune-inflammation index of approximately 2.5.

Conclusion

Elevated systemic immune-inflammation index levels were significantly associated with stress urinary incontinence, whereas associations with urgency urinary incon1.

Ma F, Cong Z-C, Zhang H, et al. Association between systemic immune-inflammation index and urinary incontinence: Evidence from the National Health and Nutrition Examination Survey. Journal of International Medical Research. 2026;54(2). doi:10.1177/03000605261419655tinence and mixed urinary incontinence were weaker and exhibited nonlinear patterns. Longitudinal studies are required to clarify the temporal relationships underlying these associations.