Prevalence and associated factors of obstructive sleep apnea in morbidly obese patients undergoing bariatric surgery

Abstract

Purpose: Our goal in this study is to determine the prevalence and associated factors of obstructive sleep apnea (OSA) in morbidly obese patients undergoing bariatric surgery.

Methods: This descriptive study was conducted at King Chulalongkorn Memorial Hospital from 2007 to 2015. Data of morbidly obese patients who underwent bariatric surgery were included using ICD-10 code for principle diagnosis "morbid obesity" (E668) and ICD-9 code for "bariatric surgery" (4389, 4438, 4439).

Results: Baseline characteristics of 238 patients who met the inclusion criteria demonstrated 49.2% male, mean age of 33.9 ± 10.8 years, and mean BMI of 52.6 ± 11.6. Sleeve gastrectomy and Roux-en Y gastric bypass surgery were performed in 51.5 and 48.5%; respectively. High risk for OSA using STOP-Bang as a screening questionnaire (≥3 points) was 92.7%. The prevalence of OSA using respiratory disturbance index (RDI) ≥ 5 was demonstrated at 85.7%. Mild, moderate, and severe OSA was observed in 8.8, 15.3, and 75.9%, respectively. Snoring, STOP-Bang score ≥ 3, fatty liver, and BMI were significantly correlated with OSA compared to the group without OSA with the odds ratio of 17.04 (p = <0.0001, 95% CI = 6.67-43.49), 16 (p = 0.01, 95% CI = 1.95-131.11), 4.75 (p = 0.001, 95% CI = 1.82-12.37), and 1.04 (p = 0.045, 95% CI = 1.0009-1.09), respectively. Comparison between non-severe and severe OSA groups demonstrated dyslipidemia and BMI to be correlated with OSA severity (odds ratio = 3.06, 95% CI 1.36-6.89, p = 0.007 and odds ratio = 1.07, 95% CI 1.03-1.13, p = 0.001, respectively).

Conclusions: Obstructive sleep apnea is frequently observed in morbidly obese patients undergoing bariatric surgery and the severity tends to be severe. Snoring, STOP-Bang score ≥ 3, fatty liver, and BMI were significantly correlated with OSA. Dyslipidemia and BMI were demonstrated to be associated factors for severity of OSA in this population.

Keywords: Bariatric surgery; Morbid obesity; Obstructive sleep apnea.