Background: Sleep apnea is a common condition and a cardiovascular risk factor. Continuous positive airway pressure (CPAP) reduces cardiovascular events and sleep apnea-related symptoms, especially in patients with obstructive sleep apnea (OSA), who occasionally experience nocturia, a common problem in individuals of advanced age.
Methods and results: The present study was a prospective, observational study including 1,429 consecutive patients with cardiovascular disease (CVD). A questionnaire on nocturia was administered and nocturnal pulse oximetry was performed. Patients with moderate-to-severe sleep-disordered breathing (SDB) underwent polysomnography, and patients with OSA received CPAP therapy. Nocturia was observed in 561 of 666 patients included in the analysis. A multiple logistic regression analysis revealed that nocturia was associated with oxygen desaturation defined as a 3% decrease (P=0.0335) independent of age (P<0.0001), male sex (P=0.0078), hypertension (P=0.0139), and B-type natriuretic peptide (BNP) level (P=0.0185). Nocturia was reduced in patients who continued CPAP treatment and they also showed a decrease in the apnea-hypopnea index (45.3±13.6 vs. 2.5±3.7 events/h, P<0.0001), systolic blood pressure (121.6±11.9 vs. 113.4±8.8 mmHg, P=0.0002), and BNP level (57.7 [15.0-144.4] vs. 27.4 [8.5-111.7] pg/ml, P=0.0006).
Conclusions: CPAP has the potential to reduce nocturia and risk factors for SDB such as increased blood pressure and BNP level, which may be beneficial in older men with CVD and OSA.