Weight loss and lifestyle intervention for cardiorespiratory fitness in obstructive sleep apnea: The INTERAPNEA trial

Introduction: Although recent trials have shown benefits of weight loss and lifestyle interventions on obstructive sleep apnea (OSA) severity and comorbidities, the effect of these interventions on cardiorespiratory fitness (CRF) remains unknown. This study aimed to investigate the effects of an interdisciplinary weight loss and lifestyle intervention on CRF and self -reported physical fitness in adults with OSA. Methods: Eighty-nine men aged 18-65 years with moderate -to -severe OSA and a body mass index >= 25 kg/m2 were randomly assigned to a usual -care group or an 8 -week interdisciplinary weight loss and lifestyle intervention. CRF was assessed through the 2 -km walking test, and the International Fitness Scale (IFIS) was used to assess self -reported physical fitness. Results: As compared with usual -care, the intervention group had greater improvements at intervention endpoint in objective CRF (6% reduction in 2 -km walking test total time, mean between -group difference, -1.7 min; 95% confidence interval, -2.3 to -1.1), and self -reported overall physical fitness (18% increase in IFIS total score, mean between -group difference, 2.3; 95% CI 1.2 to 3.3). At 6 months after intervention, the intervention group also had greater improvements in both 2 -km walking test total time (10% reduction) and IFIS total score (22% increase), with mean between -group differences of -2.5 (CI 95%, -3.1 to -1.8) and 3.0 (CI 95%, 1.8 to 4.1), respectively. Conclusions: An 8 -week interdisciplinary weight loss and lifestyle intervention resulted in significant and sustainable improvements in CRF and self -reported physical fitness in men with overweight/obesity and moderateto -severe OSA. Study registration: ClinicalTrials.gov registration (NCT03851653)