Noninvasive ventilatin efficacy for obesity hypoventilation syndrome without severe sleep apnea

Abstract

Rationale: Noninvasive ventilation (NIV) is an effective treatment in patients with obesity hypoventilation syndrome (OHS) who have severe obstructive sleep apnea (OSA). However, there is paucity of evidence on the efficacy of NIV in OHS patients without severe OSA. Objective: We performed a multicenter randomized clinical trial to determine the efficacy of NIV versus lifestyle modification (control group) using daytime PaCO 2 as the main outcome measure. Methods: Sequentially screened OHS patients without severe OSA were randomized to NIV versus lifestyle modification and were followed for two-months. Arterial blood gas parameters, symptoms, health-related quality-of-life tests, polysomnography, spirometry, six-minute walk distance test, blood pressure measure, and healthcare resource utilization were evaluated. Statistical analysis used intention-to-treat analysis. Results: 365 patients were screened and 58 were excluded. Severe OSA was present in 221 and the remaining 86 patients without severe OSA were randomized. NIV led to significantly larger improvement in serum bicarbonate and PaCO 2 (-6±5.5 mmHg versus -2.8±5 mmHg, p>0.001). Sleepiness, some health-related quality-of-life assessments and polysomnographic parameters improved significantly more with NIV than with lifestyle modification. Additionally, there was a tendency toward lower healthcare resource utilization in the NIV group. Conclusion: NIV was more effective than lifestyle modification in improving daytime PaCO 2 , sleepiness and polysomnographic parameters. Long-term randomized trials are necessary to demonstrate if NIV decreases healthcare resource utilization, cardiovascular events, and mortality.