Obstructive sleep apnea after weight loss: when should we repeat the sleep study?

Background: Obstructive sleep apnea (OSA) is a disease with a high impact on quality of life, morbidity and mortality. The relationship between obesity and OSA is well established. Aim: In our study we analyzed the effect of bariatric surgery (BC) on an OSA population of obese patients and at what weight loss a control sleep study should be scheduled. Methods: A total of 51 obese (BMI> 30Kg/m2) patients proposed for BC with an apneia/hipopneia index (AHI) > 5/h were included between 2015 and 2017. All performed a level 3 home sleep recording (HSR) before and after BC. The test statistics software used was SPSS 19.0 (t test for pared samples and multiple linear regression, significant level α = 0.05). Results: From the 51 patients evaluated 62.7% (32) were female, with a mean age of 49.61±11.88 years old. The average of weight lost that results in an improvement of IAH in this study population is 24 kg [age (p = 0.014); AHI (p = 0.05); R = 0.504 (p = 0.001)]. Conclusion: We concluded that BC can be an effective treatment for obese OSA patients with a significant impact in AHI, BMI, P90 as well as in OSA severity. Also, the ideal time to access therapy success by performing an HSR, based on a regression model for this study population, is after a loss of ≈ 24 kg after surgery.