Introduction: This post-hoc analysis examined the relationship between weight loss (WL) and endpoints related to sleep apnoea and quality of life (QoL) in the SCALE Sleep Apnoea trial. Clinicaltrials.gov NCT01557166.
Methods: Obese adults (72% male, mean age 49 years, mean apnoea-hypopnoea index [AHI] 49.2 events/h, mean body weight [BW] 117.6 kg) with moderate or severe obstructive sleep apnoea (OSA) and unable/unwilling to use continuous positive airway pressure therapy were treated with liraglutide 3.0 mg (n=180) or placebo (n=179), both as adjunct to diet and exercise counselling, for 32 weeks. A pre-specified ANCOVA model included treatment, country and gender as fixed effects and baseline age and BMI parameter values as covariates. Post-hoc analyses also included % weight change as a covariate and examined its interactions with other effects.
Results: Liraglutide significantly reduced AHI (-12.2 vs -6.1 events/h, p=0.015) and BW (-5.7 vs -1.6%, p<0.0001) compared to placebo after 32 weeks. AHI reduction was significantly associated with WL, irrespective of treatment. The reduction in AHI per %WL depended on baseline AHI, with reductions of 0.7, 1.4 and 2.8 events/h for baseline AHI cohorts <30, 30–59 and ≥60 events/h, respectively (all groups, p<0.0001). Greater WL was also significantly associated with greater improvements in oxygen saturation, sleep architecture (change in total sleep time) (p<0.01 for all) and QoL measures, including the Epworth Sleepiness Scale (ESS).
Conclusion: Greater WL and improvement of AHI were more likely with liraglutide 3.0 mg than placebo. Greater improvements in sleep apnoea endpoints and QoL were significantly associated with greater WL, irrespective of treatment. The safety profile for liraglutide 3.0 mg was generally consistent with that seen with liraglutide in type 2 diabetes.