Subjective efficacy of nasal CPAP therapy in obstructive sleep apnoea syndrome: a prospective controlled study.

The response to nasal continuous positive airways pressure (nCPAP) of a wide variety of symptoms recognized to be associated with obstructive sleep apnoea syndrome (OSAS) was examined. Fifty-six consecutive patients with OSAS, confirmed by polysomnography (mean (SD) apnoea-hypopnoea index (AHI) 49.6 (22.6) events x h(-1), Epworth score 15.4 (5.0)), were asked to complete paired symptom evaluation questionnaires, before treatment and again after 4 months of nCPAP. The response rate was 80%. A control group of 21 consecutive OSAS patients of similar age, body mass index (BMI), AHI and Epworth score to the treated group but managed with conservative measures, completed the same questionnaires on two occasions, 4 months apart. The nCPAP-treated group showed significant reductions (Wilcoxon matched pairs test) in the symptoms of daytime sleepiness, restless sleep, heartburn, nocturia, enuresis, headache and nocturnal sweating, whereas controls showed no significant changes in these symptoms. There were no changes in BMI, smoking, alcohol consumption or exercise habits in either group. It was concluded that, in addition to improvements in symptoms of daytime sleepiness and restless sleep, a wide range of other symptoms may improve significantly with nasal continuous positive airways pressure therapy.