Continuous positive airway pressure treatment results in weight loss in obese and overweight patients with obstructive sleep apnea.

Obstructive sleep apnea (OSA) is a syndrome characterized by short duration (typically less than a minute), repetitive episodes of impaired breathing during sleep. OSA and related syndromes occur in at least 3% of adults in the United States (1). Approximately 70% of patients with OSA are obese (2). Obesity contributes to the occurrence of OSA by increasing the propensity for pharyngeal obstruction (3). Mortality and cardiovascular morbidity may be increased in patients with OSA, independent of the effects of obesity (4).

Continuous positive airway pressure (CPAP) is the primary treatment for OSA (5) and it is used only at night. A small, electric-powered pressure generator, which sits on a nightstand next to the bed, generates airflow that is conveyed through plastic tubing and a mask fitted over the patient's nose. Pressure generated by CPAP keeps the pharynx from collapsing during breathing and abolishes OSA. The use of CPAP by patients with OSA results in increased daytime alertness (6) and may lead to decreased morbidity and mortality (7).

Whether use of CPAP leads to an enhanced ability to lose weight has never been evaluated to our knowledge. Anecdotal reports have shown that some patients with OSA rapidly lose weight after initiating CPAP treatment (8). Thus, we sought to determine in a systematic fashion whether CPAP use facilitates weight loss.

METHODS

Data were gathered from the records of patients investigated at the Scripps Clinic Sleep Disorders Center between April 1 and June 31, 1994. The cohort …