Postoperative CPAP use impacts long-term weight loss following bariatric surgery.

Introduction: 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.