Obstructive sleep apnea treated with continuous positive airway pressure (CPAP) promotes a statistically significant increase in BMI as well as weight, according to a literature review published on hcplive.com.

The logical assumption had been that treating obstructive sleep apnea with Continuous Positive Airway Pressure would result in improved physiologic parameters and help obese patients who wanted to lose weight be more able to do so.  This study of randomized controlled trials demonstrates the opposite is true.  While the degree of BMI and weight gain were not large over the course of the studies included (BMI increased by over 0.13 and weight increased about 0.5 kg) the finding of an increase in both BMI and weight is discouraging.