Positive and non-linear association of sagittal abdominal diameter-to-height ratio with stress urinary incontinence in US women: evidence from NHANES 2011-2016.

Background: Central obesity represents a well-established risk factor for stress urinary incontinence (SUI), with sagittal abdominal diameter-to-height ratio (SADHtR) recognized as a superior anthropometric indicator of visceral adiposity. However, the evidence between the SADHtR and SUI remains scarce. This study aimed to elucidate the association between SADHtR and SUI of adult women. Methods: This cross-sectional study incorporated 4,846 women ≥20 years from the 2011-2016 cycles of the National Health and Nutrition Examination Survey (NHANES). Multivariable-adjusted logistic and linear regression models were used to investigate the relationship between SADHtR and the prevalence and severity of SUI. Smooth curve fitting methods and a two-piecewise linear regression model were employed to examine potential nonlinear relationships. Subgroup analyses and interaction tests were performed to identify potential effect modifiers. Propensity score matching (PSM) was employed to balance confounders, strengthening the robustness of the findings. Results: A positive association was observed between SADHtR and both the prevalence and severity of SUI after adjusted for potential confounders [odds ratio (OR) =3.59; 95% confidence interval (CI): 2.75-4.69; P<0.001] (β=0.71; 95% CI: 0.23-1.19; P=0.004). The relationship between SADHtR and the prevalence of SUI exhibited non-linear dose-response, with an inflection point at SADHtR =0.14. Subgroup analyses demonstrated consistent associations across all examined cohorts and showed that the positive relationship was more pronounced among young women. Conclusions: This study demonstrated a nonlinear positive association between SADHtR and SUI risk. Our findings establish SADHtR as a valuable anthropometric measure for SUI risk evaluation.