Long-term noninvasive ventilation in obesity hypoventilation syndrome without severe obstructive sleep apnoea

Abstract

Rationale: Noninvasive ventilation (NIV) is an effective treatment in obesity hypoventilation syndrome (OHS) with severe obstructive sleep apnoea (OSA) but there is paucity of evidence in OHS patients without severe OSA phenotype.

Methods: In this multicentre (16 sites in Spain), open-label parallel group clinical trial, we randomly assigned 98 stable ambulatory patients with untreated OHS and apnoea-hypopnoea index <30 events/hour to NIV or lifestyle modification (control). The primary end point was hospitalization days/year. The analysis was performed according to the intention-to-treat and per-protocol principles.

Results: 49 patients were randomised in each group and 48 patients were analysed in each one of them. During a median [IQR] follow-up of 4.98 [2.98; 6.62] years, mean (SD) hospitalization days/year was 2.60 (5.31) in the control group and 2.71 (4.52) in the NIV group [adjusted rate ratio (95% CI) 1.07 (0.44; 2.59) (p = 0.882)]. Cardiovascular events occurred in 11 (23%) participants in the control group and 10 (21%) in the NIV group (hazard ratio (95% CI) 0.96 (0.40;2.30), p=0.927). Similar results were observed in the per-protocol analysis [rate ratio (95% CI) 1.21 (0.43;3.41) (p=0.717)]. Death occurred in 9 (19%) participants in both arms (adjusted hazard ratio (95% CI) 1.07 (0.41;2.82), p=0.893). Similar results were found in the per-protocol analysis [rate ratio (95% CI) 1.38 (0.50;3.79) (p=0.529)].

Conclusion: In stable ambulatory patients with OHS without severe OSA, NIV and lifestyle modification had similar long-term hospitalization days-year. Larger studies are necessary to better determine the long-term benefit of NIV in this subgroup of OHS.