Impact of bariatric surgery on the resolution of obesity hypoventilation syndrome at 1-year follow-up: a retrospective study.

STUDY OBJECTIVES

This study aimed to assess the effectiveness of metabolic and bariatric surgery in patients with obesity comorbid with obesity hypoventilation syndrome (OHS) at 1-year follow-up.

METHODS

This retrospective study was conducted between January 2020 and June 2023 at a metabolic and bariatric surgery center in a university-affiliated tertiary hospital in China. Clinical data, including body mass index, arterial blood gas values, portable sleep study results, and anthropometric parameters, were recorded pre- and postoperatively. Correlations between variables and risk factors for OHS resolution were analyzed.

RESULTS

Among 1,134 candidates for metabolic and bariatric surgery, 187 (16.5%) had comorbid OHS; 151 patients with OHS met inclusion criteria and completed the 1-year follow-up visit (body mass index 39.1 ± 6.8 kg/m with partial pressure of carbon dioxide in arterial blood [PaCO] 48.6 ± 3.0 mmHg). At 1-year follow-up, body mass index decreased to 29.0 ± 6.0 kg/m ( < .001) and PaCO dropped to 43.8 ± 5.5 mmHg ( < .001). Resolution of OHS, defined as awake PaCO < 45 mmHg with discontinuation of positive airway pressure therapy for a minimum of 6 months before obtaining the arterial blood gas at the 12-month visit, was achieved in 105 (69.5%) of the patients. Nonlinear analysis indicated that PaCO did not significantly decrease until the percentage of total weight loss exceeded approximately 20%. A larger reduction in waist circumference was associated with a greater reduction in PaCO, particularly when waist circumference reached less than 25 cm. Beyond this point, ΔPaCO reached a plateau. In multivariate analysis, a larger preoperative waist circumference (odds ratio: 1.046, 95% confidence interval: 1.031-1.118, .025) and arterial blood gas pH < 7.35 (odds ratio: 3.921, 95% confidence interval: 2.305-9.140, < .001) were associated with lack of resolution of OHS, and a larger percentage of total weight loss after bariatric surgery (odds ratio: 0.917, 95% confidence interval: 0.846-0.965, .001) was independently associated with OHS resolution.

CONCLUSIONS

Metabolic and bariatric surgery is an effective treatment for OHS. Achieving a sufficient percentage of total weight loss is critical for the resolution of OHS.

CITATION

Ma S, Yu W, Yang C, et al. Impact of bariatric surgery on the resolution of obesity hypoventilation syndrome at 1-year follow-up: a retrospective study. 2025;21(10):1665-1678.