Assessment of Obstructive Sleep Apnea in Adults Undergoing Bariatric Surgery in the Longitudinal Assessment of Bariatric Surgery-2 (LABS-2) Study

Study Questions:

What is the frequency of diagnostic testing for obstructive sleep apnea (OSA), prevalence of OSA, and factors independently associated with OSA status in adults undergoing bariatric surgery?


This was an observational cohort of 2,458 adults undergoing bariatric surgery at 10 US hospitals. Within 30 days prior to surgery, researchers determined if participants had a diagnostic polysomnography (PSG) in the previous 12 months. When available, apnea-hypopnea index (AHI) was recorded. Based on medical records and participant report, research clinicians recorded OSA status and positive airway pressure (PAP) use. Participants completed the Berlin Questionnaire (BQ). Multivariable logistic regression was used to determine factors independently associated with AHI-confirmed OSA status.


Participants were 78% female, median age 45 years, and median body mass index was 46 kg/m2. Nearly 29% (n = 693) had a PSG within 12 months before surgery. Of subjects with AHI available (n = 509), 80.7% (n = 411) had OSA (AHI ≥5); 83.0% (n = 341) with confirmed OSA reported PAP use. In participants without a known AHI (n = 1,949), 45.4% (n = 884) had self-reported OSA; 81.2% (n = 718) reported PAP use. Self-reported history of snoring and pauses in breathing (odds ratio [OR], 10.0; 95% confidence interval [CI], 4.8-20.6), male sex (OR, 5.1; 95% CI, 1.7-15.3), older age (OR, 1.4; 95% CI, 1.2-1.6 per 5 years), and larger sagittal abdominal diameter (OR, 1.8; 95% CI, 1.2-2.5 per 5 cm) were independently associated with a greater odds of confirmed OSA.


The authors concluded that preoperative diagnostic testing for OSA was infrequent. Prevalence estimates of OSA differed greatly between those with and without a past-year AHI (81% vs. 46%, respectively). Most BQ responses did not differentiate OSA status, but endorsement of snoring and pauses in breathing were independently associated with presence of OSA.


The cost and inconvenience of PSG led investigators to identify a screening tool to determine the risk of OSA. Since the BQ did not differentiate OSA status, future studies may utilize alternative screening surveys. Larger questions remain in this population as to whether treating OSA prior to bariatric surgery reduces perioperative risks and if bariatric surgery leads to complete resolution of OSA.

Clinical Topics: Heart Failure and Cardiomyopathies, Sleep Apnea

Keywords: Snoring, Bariatric Surgery, Polysomnography, Sagittal Abdominal Diameter, Obesity, Morbid, Berlin, Respiration, Sleep Apnea, Obstructive, Sleep Apnea Syndromes

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