Bladder outlet obstruction is associated with bladder oversensitivity in women

Introduction and hypothesis: Bladder outlet obstruction (BOO) in women might be associated with significant lower urinary tract storage symptoms such as increased frequency, urgency, and incontinence. This prospective study was designed to assess whether there is an objective association between BOO and abnormal parameters during filling cystometry in women. Methods: A total of 169 consecutive women (mean age 56 ± 14 years) who were referred for urodynamic investigation were prospectively recruited. Comprehensive medical, obstetric, and gynecological histories were recorded. All patients underwent physical examination, renal and bladder ultrasound, and filled out the International Prostate Symptoms Score (IPSS) questionnaire. The cohort was divided into obstructed and un-obstructed groups based on pressure flow results (Obstruction: Q_max <12 ml/s and P_det @ Q_max >25 cmH₂O). Result: There was no significant difference in the frequency of detrusor overactivity between the obstructed and non-obstructed group (37% vs 32%, p = 0.71). All bladder sensation volumes were significantly lower in obstructed women than non-obstructed women in univariate and multivariate logistic regression analyses. Of the sensation parameters, first desire to void (FDV) had the highest area under the curve (AUC = 0.75, 95% CI = 0.672–0.837, p < 0.001) for predicting BOO. FDV < 105 ml showed a strong association with BOO with OR = 9.84 (95% CI 4.122–23.508, p < 0.0001). On univariate and multivariate analyses adjusted to 50 cc reduction in sensation volume, all sensation parameters, were associated with bladder outlet obstruction. Conclusion: Our results suggest that there might be a strong association between bladder oversensitivity and BOO in women. This may shed light on the pathophysiological connection between obstruction and enhanced afferent signaling from the bladder.