title: Postoperative CPAP use impacts long-term weight loss following bariatric surgery.
abstract: BACKGROUND
  Obstructive sleep apnea (OSA) is common among bariatric surgery candidates. After surgical weight loss, OSA frequently persists and untreated OSA can lead to weight gain. Long-term continuous positive airway pressure (CPAP) adherence is unclear and poor adherence may worsen weight loss outcomes. We sought to determine the impact of CPAP use on long-term weight-loss outcomes in a cohort of bariatric patients.
  
  
  METHODS
  Long-term observational study of bariatric surgery patients with OSA. Patients were evaluated with polysomnography preoperatively and one-year postoperatively. The cohort was again evaluated a mean of 7.2 years later to determine the relationship between long-term CPAP use and subsequent regain of weight.
  
  
  RESULTS
  Twenty-four consecutive patients (aged 48.5 ± 9.4 years at time of surgery; 73% female) were included in the initial assessment, and long-term outcome data were available on 22 subjects. Persistent OSA was documented in 21 of 22 subjects (95%) one year postoperatively. Final evaluation occurred 7.2 ± 2.3 years following surgery. Weight (213.3 ± 39.1 to 235.3 ± 47.1 lb, p = 0.10) and BMI (32.5 ± 5.4 to 37.3 ± 8.2 kg/m(2), p = 0.03) increased in most (n = 19, 86.4%) from postoperative to final evaluation. CPAP use declined from 83.3% (preoperatively) to 38.1% (one year) and to 23.8% (final evaluation). BMI increased among those not using CPAP at long-term follow-up compared to those with continued CPAP use (6.8% v -1.8%, p = 0.05).
  
  
  CONCLUSIONS
  In our cohort of bariatric patients with OSA, long-term adherence to CPAP therapy was poor, and non-adherence was associated with weight gain. Ongoing follow-up of OSA in this population may help to preserve initial achievements after surgical weight loss.
authors.affiliation: Pulmonary, Critical Care, and Sleep Medicine, San Antonio Military Medical Center, Fort Sam Houston, TX.|Department of Medicine, Uniformed Services University, Bethesda, MD.
authors.forename: Jacob
authors.initials: J
authors.lastname: Collen
authors.affiliation: Pulmonary, Critical Care, and Sleep Medicine, Walter Reed National Military Medical Center, Bethesda, MD.|Department of Medicine, Uniformed Services University, Bethesda, MD.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Lettieri
authors.affiliation: Department of Medicine, Uniformed Services University, Bethesda, MD.|Integrative Cardiac Health Project, Walter Reed National Military Medical Center, Bethesda, MD.
authors.forename: Arn
authors.initials: A
authors.lastname: Eliasson
mesh_terms: D050110:Bariatric Surgery; D045422:Continuous Positive Airway Pressure; D005260:Female; D006801:Humans; D008297:Male; D010349:Patient Compliance / Q000706:statistics & numerical data; D011184:Postoperative Period; D020181:Sleep Apnea, Obstructive / Q000628:therapy; D016896:Treatment Outcome; D015431:Weight Loss
keywords: CPAP adherence; bariatric surgery; obesity; obstructive sleep apnea; sleep disorder