The effect of continuous positive airway pressure on nocturia in patients with obstructive sleep apnea syndrome

Objective The prevalence of nocturia in patients with obstructive sleep apnea syndrome (OSAS) who received continuous positive airways pressure (CPAP) treatment was studied as well as the effect of CPAP treatment on nocturia. Methods All patients that were referred to the pulmonology department of a large teaching hospital in the Netherlands and received a CPAP mask for OSAS were interviewed and invited to take part in the study (N = 274). After informed consent, all patients were asked about the number of nocturia episodes before and after CPAP. Results In this prospective analysis, 274 patients (190 male and 84 female) were included. The mean age was 60.3 years (SE = 0.7). Sixty-four patients (23.4%) reported no nocturia episodes before CPAP and 210 patients (76.4%) reported >= 1 nocturia episode(s). Treatment of OSAS with CPAP reduced nocturia with one or more episodes per night in 42.3% of the patients. Clinically relevant nocturia (>= 2 voids per night) was reduced from 73.0% to 51.5%. There were no statistically significant gender differences. Conclusion The prevalence of nocturia in patients diagnosed with OSAS is 75.8% in both sexes. After treatment with CPAP, almost half of patients experienced a decrease in the nocturia frequency of one or more voids. Clinically relevant nocturia was reduced with one-third after CPAP. CPAP not only reduced the number of voids during the night but also improved the associated quality of life.