Effect of behavioral weight loss on overactive bladder symptoms: a prospective cohort study

Although obesity has been linked to overactive bladder (OAB), the degree of weight loss needed for meaningful symptom improvement remains unknown. This study aims to evaluate the effects of behavioral weight loss (BWL) on OAB symptoms and to identify predictive threshold for clinically meaningful improvement. Women with concurrent overweight or obesity and OAB were prospectively enrolled in a 6‑month BWL program at our centre from September 2023 to January 2024. The Overactive Bladder Symptom Score (OABSS) was assessed at baseline and at follow-up. A ≥ 3‑point reduction in OABSS defined the effective group; the remaining participants were classified as the ineffective group. The baseline characteristics and the magnitude of weight loss were compared between the two groups. Correlation analysis was performed to examine the relationship between OABSS reduction and both percent weight loss and reduction in fat mass percentage (FM%). Receiver operating characteristic (ROC) analysis was used to determine optimal cut‑offs for percent weight loss and FM% reduction for predicting OAB improvement. Of 47 participants who completed the 6-month follow-up, 22 (46.8%) achieved a ≥3-point reduction in OABSS (effective group) and 25 were classified as ineffective. No significant differences in baseline characteristics were observed between the two groups; however, the effective group showed significantly greater weight loss than the ineffective group (9.73% vs. 6.00%, p = 0.010). There was a moderate positive correlation between OABSS reduction and percent weight loss ( r = 0.542) and a weak positive correlation with FM% reduction ( r = 0.405). ROC analysis identified a percent weight loss threshold of 7.75% (sensitivity 63.6%, specificity 84%) and a threshold of 4.53% for FM% reduction (sensitivity 86.4%, specificity 60%) for predicting OAB improvement. BWL effectively improves OAB symptoms, and the degree of improvement correlates with the magnitude of weight loss. This study provides, for the first time, preliminary quantitative targets (7.75% weight loss or 4.53% FM% reduction) for achieving clinically meaningful OAB symptom improvement, offering a reference for setting weight loss goals in this patient population. NCT05987085