Prevention of Recurrent Acute Uncomplicated Cystitis by Increasing Daily Water in Premenopausal Women: A Prospective, Randomized, Controlled Study

BACKGROUND: Increased hydration is commonly recommended as a preventive measure for women with recurrent acute uncomplicated cystitis (rAUC), but supportive data are sparse. The aim of this study was to assess the efficacy of increased daily water intake on the frequency of rAUC in premenopausal women. METHODS: 140 healthy premenopausal asymptomatic women drinking less than 1.5 L of total fluid daily (24 hours) and suffering from rAUC ((3)3 episodes in the past year) were randomized to receive, in addition to their usual daily fluid intake, either 1.5 L water daily (water group) or no additional fluids (control group), for 12 months. Assessments of daily water and total fluid intake, urine volume and osmolality, number of urine voids, and occurrence of AUC symptoms and a reminder to notify investigators of any such symptoms were performed at baseline, 6- and 12-month clinic visits in addition to monthly telephone calls. The primary outcome was frequency of rAUC episodes ((3)1 AUC symptom and (3)10(3) CFU/mL of a uropathogen in voided urine) over 12 months. RESULTS: Between baseline and 12 month’s follow-up, the water group, compared with the control group, had statistically significant increases in mean daily water intake (1.15 vs. −0.01 L), total fluid intake (1.65 vs. 0.03 L), urine volume (1.40 vs. 0.04 L), and number of urine voids (2.2 vs. −0.2), and a decrease in urine osmolality (−408 vs. −35 mOsm/Kg). The mean number of rAUC episodes in the water group was significantly less than in the control group (1.6 vs. 3.1; odds ratio 0.52, 95% CI 0.46–0.60, P < 0.0001) (figure shows cumulative sum of AUC episodes over 12 months in both study groups). The mean number of antimicrobial regimens used to treat AUC events was 1.8 in the water group vs. 3.5 in the control group (P < 0.0001). In addition, the mean number of days to first rAUC and the mean number of days between rAUC episodes was longer in the water group compared with the control group (148 vs. 93, P = 0.0005 and 143 vs. 85, P < 0.0001, respectively). CONCLUSIONS: Our results provide strong evidence that increased water intake is an effective antimicrobial-sparing preventive strategy for women with rAUC. Increasing daily water intake by approximately 1.5 L reduced rAUC episodes by 48% and antimicrobial regimens by 47% over 12 months. DISCLOSURES: M. Vecchio, Danone Research: Employee, Salary. A. Iroz, Dzanone Research: Employee, Salary. I. Tack, Danone Research: Consultant, Consulting fee and Speaker honorarium. Q. Dornic, Danone research: Employee, Salary. I. Seksek, Danone Research: Employee, Salary.