Fluid intake behavior in women with refractory overactive bladder undergoing third line therapy

Introduction and Objectives: Fluid intake has been shown to be related to urinary symptoms, but no studies to date have investigated the effect of fluid intake on urinary symptoms in women with refractory overactive bladder (OAB). As this group of women are considered to have a possible unique pathophysiologic mechanism of OAB, we investigated the relationship between fluid intake, fluid intake behavior, and urinary symptoms in women with refractory OAB. Methods: A prospective cross-sectional study of women with refractory OAB was conducted by assessing the relationship between fluid intake and lower urinary tract symptoms (LUTS) in women undergoing third line OAB therapies. Fluid intake and behavior were measured by the questionnaire based voiding diary and urinary symptoms were measured by the International Consultation on Incontinence Questionnaire for Female Lower Urinary Tract Symptoms (ICIQ-FLUTS). The relationship between fluid intake and symptom severity was assessed using Spearman's rank correlation and χ² tests. Results: Of the 126 individuals undergoing third line therapy for OAB, 60 (48%) underwent intradetrusor onabotulinumtoxinA injection (BTX) injection, 42 (33%) peripheral tibial nerve stimulation, and 24 (19%) sacral neuromodulation. The mean total daily fluid intake was 2567.0 ± SD 1292.4 mL and did not differ significantly across treatment groups. Total fluid intake was weakly correlated with worse filling-type LUTS (r = 0.241, p = 0.007), and there was no relationship between LUTS and caffeinated fluid intake. Half (52%) of the subjects reported current fluid restricting behavior to control urinary symptoms, but this behavior was not correlated with LUTS severity (all p > 0.05). Patients that currently use tobacco have greater LUTS (current = 25.8 ± SD 9.5, former = 14.8 ± SD 6.1, never = 15.0 ± SD 6.1; p < 0.001). BMI was also positively correlated with worse incontinence symptoms (r = 0.351, p < 0.001). Conclusions: Fluid intake along with other lifestyle factors, including tobacco use and weight, are minimally related to the symptomatology seen in women with refractory OAB. Further studies are needed to assess if behaviors change during treatment with third line therapies, and if these behavioral changes may affect treatment response.