Higher BMI and Depression Linked to Greater Risk of Urinary Incontinence in Women: NHANES Study

The researchers reported that women with a BMI over 30 were more than twice as likely to experience urinary incontinence compared to those with a lower BMI (OR 2.53). They further highlighted that depressive symptoms contributed to nearly 7% of the increased risk, emphasizing the importance of a holistic approach that integrates both mental health support and weight management in addressing UI.

Urinary incontinence is associated with body mass index (BMI), with the potential for depressive symptoms to influence this relationship. Kun Li, Department of Urology, The Third Hospital of Mianyang, Sichuan Mental Health Center, Mianyang, China, and colleagues sought to examine the connection between BMI and the risk and frequency of UI in adult women, particularly emphasizing the role of depressive symptoms, as measured by the Patient Health Questionnaire-9 (PHQ-9), in mediating this association.

For this purpose, the researchers analyzed data from 6,107 adult women in the National Health and Nutrition Examination Survey (2005-2018). They used weighted multivariable-adjusted regression analysis to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between BMI and urinary incontinence. Restricted cubic spline (RCS) analysis was employed to assess nonlinear relationships, while causal mediation analysis explored the mediating role of depressive symptoms, with subgroup analyses stratified by PHQ-9 score.

The study led to the following findings:

• Higher BMI was linked to a greater risk and frequency of urinary incontinence (UI).
• As BMI increased across quartiles, the risk of UI progressively rose from Q2 to Q4.
• In the fully adjusted model, the odds ratio (OR) for UI risk in Q4 compared to Q1 was 2.53, with a significant trend observed across quartiles.
• Restricted cubic spline (RCS) analysis showed a nonlinear relationship, with UI risk increasing notably at BMI levels above 30.
• Depressive symptoms were independently associated with higher UI risk and frequency.
• Mediation analysis revealed that depressive symptoms (as measured by PHQ-9 score) contributed to approximately 6.8% of the effect of BMI on UI risk and 6.5% on UI frequency.

In summary, the study highlights that both elevated BMI and depressive symptoms are independently linked to a higher risk and frequency of urinary incontinence among adult women.

The authors also found that depressive symptoms played a significant mediating role, emphasizing the need to address both mental health and weight management to reduce the risk of UI. These findings support the importance of a holistic approach to UI prevention and treatment, integrating strategies that focus on both physical and mental health.

Reference:

Li, K., Yan, X., Zhang, M. et al. Body Mass Index and Depressive Symptoms as Risk Factors for Urinary Incontinence in Women: A Nationally Representative Study. Int Urogynecol J (2025). https://doi.org/10.1007/s00192-025-06140-y