Effect of a self-directed lifestyle-based weight management program among patients with comorbid COPD and sleep apnea: a secondary analysis of the INSIGHT COPD trial

Rationale: Excess weight contributes to impaired physical function among individuals with chronic obstructive pulmonary disease (COPD) and sleep apnea. Self-directed lifestyle-based weight management programs are an accessible option to promote weight loss and improve physical function, but their effectiveness has not been clearly demonstrated. Objective: To test whether a self-directed lifestyle program improves 6-minute walk test (6MWT) distance among individuals with COPD and comorbid sleep apnea. Study Design and Methods: We performed a subset analysis of participants previously enrolled in the INSIGHT-COPD randomized clinical trial (low-intensity lifestyle intervention vs usual care) who self-reported a diagnosis of sleep apnea. Our primary outcome was between-group differences for change in 6MWT distance (minimally important difference [MID] 30 m). Secondary outcomes included between-group differences in weight (a loss of 3% defines meaningful reduction) and quality of life (SF-12 Physical Component Score [PCS], MID 3-3.5 points). We also tested whether sleep apnea modified the effect of the intervention across the entire INSIGHT-COPD population. Measurements and Main Results: Among 285 participants with sleep apnea (141 randomly allocated to intervention, 144 to usual care), those randomized to intervention could walk further (difference in 6MWT distance of 25.5m, 95% CI 8.2m to 42.9m; 23.4% vs 20.1% had a MID increase in 6MWT distance) and had a greater reduction in weight (difference in weight of −2.4 kg, 95% CI −3.9 to −0.9 kg; 36.2% vs 23.6% had a 3% reduction in weight) at 12months. The intervention group also reported a greater physical-function-related quality of life (difference in SF-12 PCS of 1.78 pts, 95% CI 0.10 to 3.49) in comparison to usual care at 12months. Conclusions: Among patients with COPD and sleep apnea, a self-directed video-based weight management program led to favorable changes in 6MWT distance compared to usual care, though this did not meet the threshold of a clinically important improvement. However, fewer participants in the intervention group saw a decline in 6MWT distance, and more achieved meaningful weight loss. To effectively improve function in this population, additional interventions beyond self-directed weight management will be necessary. Clinical trial registered with www.clinicaltrials.gov (NCT 02634268).