Obstructive Sleep Apnea Syndrome as a Potential Cause of Nocturia in Younger Adults

Abstract

Objectives: To investigate the impact of age on the relationship between obstructive sleep apnea syndrome (OSAS), nocturia, and other lower urinary tract symptoms (LUTSs).

Methods: This was a secondary analysis study based on data derived from a previously conducted prospective observational cohort study on OSAS and nocturia. We analyzed 90 subjects who were suspected of having OSAS. Prior to polysomnography, we assessed International Prostate Symptom Score-Quality of Life scores, Overactive Bladder Symptom Scores, and International Consultation on Incontinence Modular Questionnaire-Nocturia Quality of Life scores to evaluate LUTSs. Nocturnal urine volume, night-time frequency, and night-time urine electrolyte content were measured during polysomnography. Patients were divided into groups according to age and OSAS severity determined using apnea-hypopnea index (AHI) scores. Young patients were those aged <65 years and elderly patients, ≥65 years. A multiple linear regression with multiple imputations was performed to examine the association of night-time frequency with demographic, polysomnographic, and clinical characteristics.

Results: In young patients, night-time frequency was significantly associated with nocturnal urine volume, AHI score, and total IPSS. However, night-time frequency in elderly subjects was not associated with demographic and polysomnographic characteristics. In order to compare the severity of OSAS, night-time frequency and urinary sodium content significantly increased only in young patients (P = .007 and .004, respectively).

Conclusion: OSAS is a strong candidate of causative factor for nocturia in younger individuals. When a younger patient complains nocturia without any urological disorders, OSAS should be kept in mind as a potential cause of nocturia.