Sleep apnoea in patients undergoing bariatric surgery

INTRODUCTION: The objective of this study was to investigate the presence of obstructive sleep apnoea (OSA) among patients awaiting bariatric surgery and to evaluate if a change in symptoms and clinical measurements of OSA was seen one year after bariatric surgery.
 Methods: Patients awaiting bariatric surgery in the Region of Southern Denmark were invited to participate in an OSA examination during a 15-month period (2012-2013) using the Embletta device for cardiorespiratory monitoring before and one year after bariatric surgery. The Apnoea-Hypopnoea Index (AHI), weight, BMI and the Epworth Sleepiness Score (ESS) were measured prior to and one year after surgery. 
Results: A total of 56 patients were enrolled in the study, and 59% were found with OSA (AHI ≥ 5). Thirty-six patients were eligible for examination one year post-operatively. Twelve of these patients did not have OSA (AHI < 5) either at inclusion or at re-examination. In the remaining 24 patients with OSA, the BMI dropped from 44.4 prior to surgery to 30.8 kg/m2 one year after surgery (p < 0.01). Mean AHI decreased from 12.8 prior to surgery to 3.7 one year after surgery (p < 0.01). There was no effect of weight reduction on the ESS.
 Conclusions: A statistically significant reduction in AHI was seen in patients with OSA one year after surgery. 
No statistical differences were observed for ESS. 
Funding: This study was funded by "Fonden for Laege-videnskabelig Forskning m.v. ved sygehusene i Region Syd" and by "Edith og Vagn Hedegaard Jensen fond".
Trial registration: ClinGov (ID: S-20120004jln).