Effect of the continuous positive airway pressure on the nocturnal urine volume or night-time frequency in patients with obstructive sleep apnea syndrome.

Objective To evaluate the effect of continuous positive airway pressure (CPAP) treatment on nocturnal urine volume, night-time urine frequency, and quality of life (QOL) in patients with obstructive sleep apnea syndrome (OSAS). Methods Ninety-eight participants with suspicious diagnosis of OSAS were prospectively enrolled in this study. Before polysomnography, measurement of the International Prostate Symptom Score–QOL score, the Overactive Bladder Symptom score (OABSS), the International Consultation on Incontinence Modular Questionnaire–Nocturia QOL were carried out to evaluate the lower urinary tract symptoms. During polysomnography, nocturnal urine volume and night-time urine frequency were recorded, and the concentrations of electrolytes in urine were determined. OSAS was confirmed in 92 patients, and 63 patients started to undergo CPAP treatment. Change in lower urinary tract symptoms–related QOL was assessed 1 month after CPAP treatment in 51 patients. Additionally, urine was collected at the time of CPAP titration in 25 patients. Results CPAP treatment significantly improved night-time frequency, which resulted in the improvement of total IPSS and QOL score. The night-time frequency questionnaire in OABSS similarly decreased, although total OABSS scores were not significantly improved. The International Consultation on Incontinence Modular Questionnaire–Nocturia QOL showed no significant changes after CPAP treatment. In addition to the night-time frequency, nocturnal urine volume and urine electrolyte contents significantly decreased after CPAP treatment. Conclusion CPAP treatment decreases night-time urine frequency by reducing nocturnal urine volume and improves QOL in OSAS patients.