Association between nighttime urinary frequency and clinical outcomes in Japanese patients with ulcerative colitis.

Introduction: Nocturia is a common symptom of lower urinary tract syndrome (LUTS). In previous studies, a close association between LUTS and colorectal inflammation has been reported. However, evidence regarding the association between nighttime urinary frequency and ulcerative colitis (UC) is limited. Herein, we investigated the association between nighttime urinary frequency and clinical outcomes of UC.

Methods: We surveyed 287 Japanese patients with UC. A self-administered questionnaire was used to collect the information on the variables studied. Patients were divided into three groups based on nighttime urinary frequency: (1) no voids, (2) one void, and (3) two or more voids. The assessment of clinical outcomes was based on mucosal healing (MH) and clinical remission (CR). The association between nighttime urinary frequency and prevalence of MH and CR was evaluated using multivariate logistic regression analyses.

Results: The prevalence of one nighttime frequency and two or more nighttime frequency in this cohort was 35.5% and 26.8%, respectively. The percentage of MH and CR was 24.7% and 59.2%, respectively. Two or more nighttime frequency (adjusted odds ratio [OR]: 0.31, 95% confidence interval [CI]: 0.13-0.73) was independently and inversely associated with MH. In nonelderly patients (<70 years) and patients in CR, an association between two or more nighttime frequency and MH remained significant (non-elderly: adjusted OR: 0.27, 95% CI: 0.09-0.72 and only CR: adjusted OR: 0.34, 95% CI: 0.12-0.90).

Conclusion: Nighttime urinary frequency was independently and inversely associated with MH in Japanese patients with UC. Nighttime urinary frequency may serve as a complementary physical sign of MH in patients with UC.