The relationship between obstructive sleep apnea, nocturia, and daytime overactive bladder syndrome in women

Objective: The purpose of this study was to corroborate the association between obstructive sleep apnea (OSA) and nocturia in a clinical sample of urogynecologic patients and to explore whether night-time urine concentration predicts the presence of OSA. Study Design: Patients with nocturia and control subjects underwent a home sleep study, completed validated nocturia questionnaires, and provided evening and morning urine specimens that were analyzed for osmolarity. Results: Twenty-one patients with nocturia (16 of whom also had daytime overactive bladder [OAB] symptoms) and 10 control subjects were studied. OSA was present in 17 of 21 women (81%) with nocturia: 13 women (81%) with OAB, 4 women (80%) with nocturia/no OAB, and 4 control subjects (40%; P < .001). The percentage of rapid eye movement sleep time was correlated inversely with nocturic frequency (ρ = -.51; P < .004). The presence of diluted nighttime urine in a patient with nocturia was 88% sensitive for the presence of OSA. Conclusion: We should consider a diagnosis of OSA in all patients with nocturia, even those patients with daytime OAB.