Association between the triglyceride-glucose index and its correlation indices and stress urinary incontinence in American adult women: a population-based cross-sectional study

Introduction
The relationship between the triglyceride-glucose (TyG) index – a reliable surrogate marker of insulin resistance – and stress urinary incontinence (SUI) in women remains insufficiently explored.

Material and methods
We analysed cross-sectional data from 9,184 women aged 20 years and older, obtained from the National Health and Nutrition Examination Survey cycles spanning from 2001 to 2023. Stress urinary incontinence was defined based on self-reported urine leakage during physical exertion. The triglyceride-glucose index was calculated as ln[fasting triglycerides (mg/dl) × fasting glucose (mg/dl)/2], and its derivatives were computed by multiplying TyG with body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR), respectively. Multivariable logistic regression models, adjusted for sociodemographic, behavioural, and clinical covariates, were employed to assess independent associations. Dose-response relationships were examined using tertile analyses, and nonlinear associations were explored with restricted cubic splines.

Results
The overall prevalence of SUI was 41.77% (n = 3,836). In fully adjusted models, all TyG-related indices demonstrated significant, dose-dependent positive associations with SUI risk. Compared to the lowest tertile (T1), the highest tertile (T3) exhibited markedly increased odds of SUI: TyG (odds ratio (OR) = 1.46, 95% CI: 1.29–1.66), TyG-BMI (OR = 2.50, 95% CI: 2.21–2.82), TyG-WC (OR = 2.29, 95% CI: 2.02–2.59), and TyG-WHtR (OR = 2.39, 95% CI: 2.10–2.71), with all p-values < 0.001. Nonlinear relationships were statistically significant (p < 0.05).

Conclusions
Elevated levels of TyG-derived indices, particularly TyG-BMI and TyG-WHtR, are independently associated with an increased prevalence of SUI among U.S. adult women.