Urinary incontinence among Korean women with co-occurring central obesity and depressive symptoms: a KNHANES IV cross-sectional study

Urinary incontinence can coexist with metabolic and psychological burdens that are often considered separately in research and clinical assessment. We examined whether women with both central obesity and depressive symptoms had a disproportionate burden of current urinary incontinence. We analyzed Korea National Health and Nutrition Examination Survey IV (2007–2009) data for 8,794 women aged 19 years or older. Women were grouped by central obesity (waist ≥ 85 cm) and self-reported depressive symptoms lasting at least two weeks during the past year. Survey-weighted logistic regression estimated associations with current urinary incontinence, with all main models fitted in the same sample. Additive interaction was estimated from model-standardized prevalences and multiplicative interaction from a product term. Sensitivity analyses examined alternative exposure definitions, models with and without hypertension and diabetes, and additional adjustment for body mass index and reproductive factors. Of the 8,794 women, 723 had current urinary incontinence; 530 women had both exposures, including 92 cases. Fully adjusted standardized prevalence of current urinary incontinence was 6.1% (95% CI 5.3–6.9) with neither exposure, 7.2% (5.8–8.5) with central obesity only, 6.5% (4.8–8.2) with depressive symptoms only, and 12.8% (9.2–16.5) with both. The both-exposure group had higher adjusted odds (OR 2.31, 95% CI 1.61–3.32), whereas single-exposure associations were not clear. The standardized additive interaction contrast was 5.29% points (95% CI 1.65–8.94), the multiplicative interaction OR was 1.81 (95% CI 1.19–2.76), and the synergy index was imprecise. In the same sample, the both-exposure OR was 2.32 without and 2.31 with adjustment for hypertension and diabetes; among the 8,789 women with body mass index available, additional adjustment for body mass index changed it from 2.31 to 1.95 (95% CI 1.35–2.83). Sensitivity analyses supported the joint association more consistently than interaction across definitions. Women with co-occurring central obesity and depressive symptoms had a greater burden of current urinary incontinence. These are adjusted cross-sectional associations, not causal or mediated effects. The findings support attention to metabolic and mood symptoms during assessment of urinary leakage, with prospective evaluation needed to clarify clinical applications.