Background Obstructive Sleep Apnoea Syndrome (OSAS) is common in morbidly obese patients. Previous studies indicate bariatric surgery reduces the severity of OSAS but may not cure it. We explored the impact bariatric surgery on patients who were commenced on CPAP prior to surgery.
Methods All morbidly obese patients who underwent bariatric surgery at our institution, between June 2010 and May 2014 who underwent sleep study (SS) or oximetry prior to bariatric surgery were included. The primary end point was cure (oximetry off CPAP showing either ODI less than 5 or ODI 5–15 with ESS <10 and no other symptoms of SDB) from OSAS. Secondary end points were weight loss achieved, improvement in OSAS and improvement in ESS. All data were obtained from electronic bariatric surgery and sleep service databases.
Results 184 patients underwent bariatric surgery. 97 (52.7%) had SS or oximetry prior to surgery. (Figure 1) Mean ODI was 25 (95% CI 19–30) and ESS 12 (95% CI 10–13). Out of 46 patients considered for CPAP, 45 continued using CPAP peri-operatively, one discontinued after failed trial. 20 (43.4%) patients were considered cured from OSAS by 12–24 months. 17 (36.9%) patients became asymptomatic and returned CPAP were considered to be cured clinically but not had SS post surgery. At 12 months post bariatric surgery, there were significant (P < 0.0001) reductions in various parameters; means of difference in ODI 34, ESS 10 and BMI 17.8.
Discussion and conclusion In contrast to the meta-analysis (Greenburg et al. 2009) in which 62% had residual disease in our cohort 80% had clinical cure and they had a lower post-op ODI (7.1) in spite of comparable weight loss. Even though our patients had similar pre-op BMI but the mean pre-op ODI was less than most reported studies the reason for which is not clear but might be responsible for a much higher cure rate.
Reference 1 Greenburg DL, Lettieri CJ, Eliasson AH. Effects of surgical weight loss on measures of obstructive sleep apnea: a meta-analysis. Am J Med 2009;122:535–42