Abstract

Background: In clinical practice, patients with mild to moderate obstructive sleep apnoea (OSA) may be managed with different treatment options. This study compared the effectiveness of three commonly used non- surgical treatment modalities.

Methods: Subjects with mild to moderate OSA were randomised to one of three treatment groups for ten weeks: conservative measures (CM: sleep hygiene) only, continuous positive airways pressure (CPAP) or oral appliance (OA) in addition to conservative measures. All overweight subjects were referred to weight reduction class. OSA was assessed with polysomnogram. Blood pressure was recorded in the morning and evening in the sleep laboratory. Daytime sleepiness was assessed with Epworth Sleepiness Scale. Health-related quality of life (HRQOL) was assessed with the 36-Item Short-Form Health Survey (SF-36) and Sleep Apnoea Quality of Life Index (SAQLI).

Results: 101 subjects with mean apnoea-hypopnoea index of 21.4±1.1 (mean±) were randomized to one of the three groups. Severity of sleep disordered breathing was decreased with device use in both CPAP and OA groups compared to CM group, and CPAP was significantly better than OA. Relief of sleepiness was significantly better in the CPAP group. CPAP was also better than either OA or CM in improving the 'bodily pain' domain, and better than CM in improving the 'physical function' domain of SF-36. Both CPAP and OA were more effective than CM in improving the SAQLI, though no difference was detected between the CPAP and OA groups. CPAP and OA significantly lowered the morning diastolic blood pressure compared to their own baseline, but there was no difference in the changes of blood pressure among the groups. There was also a linear relationship between the changes in AHI and body weight.

Conclusion: CPAP produced the best improvement in terms of physiologic, symptomatic and HRQOL measures, while OA was slightly less effective. Weight loss, if achieved, resulted in improvement in sleep parameters, but weight control alone was not uniformly effective.