Researchers from Baylor College of Medicine in Houston found that individuals using CPAP are prone to weight gain due to decreased energy expenditure from a reduction in an active need to breathe.

The team studied electronic medical records of veterans diagnosed with OSA and treated with CPAP from January 2005 through May 2005, for baseline data. They examined sleep apnea severity, weight, blood pressure, and blood glucose levels before and after initiation of CPAP.

Of the 61 patients studied, including 58 men and three women, with an average age of 63.8 years, the researchers found a trend toward weight gain at 1 year and a statistically significant weight gain at 2 years compared with baseline.

The research was presented at CHEST 2011.