0553 THE EFFECT OF COMPLIANT CPAP USE ON WEIGHT LOSS

Abstract

PURPOSE: Introduction Obstructive sleep apnea (OSA) is a chronic condition characterized by repetitive episodes of upper airway collapse during sleep. The effects of intermittent hypoxia and re-oxygenation may provoke a number of pathological cascades, leading to an association between OSA with obesity, insulin resistance, metabolic syndrome, and cardiovascular disease. Sleep fragmentation, which exists in OSA, leads to elevation of the pro-inflammatory cytokines and catecholamines, both of which have been associated with increased visceral fat production and increased BMI. OSA is treated with continuous positive airway pressure (CPAP). Patients who are compliant with effective CPAP treatment have improved hypoxia and a decreased risk of cardiovascular events. This study evaluated the relationship between weight change and CPAP therapy. Our hypothesis was that effective CPAP therapy will improve the metabolic derangements that promote weight gain in OSA, leading to weight loss. METHOD(S): A chart review of all eligible patients with OSA newly diagnosed from January 2013 to June 2013 (n=78) was conducted. Subjects were followed for two years and divided into those compliant with CPAP therapy and those who were not. Compliance was defined as the use of CPAP for at least four hours a night or 70% duration. Co-morbid conditions commonly affecting weight, including chronic obstructive pulmonary disease, diabetes, congestive heart failure, and active cancer, were recorded. Participation in a weight loss program and the severity of OSA defined by the apnea-hypopnea index were also recorded. The primary outcome was the overall change in weight with compliant CPAP therapy after one and two years compared to those who were not compliant. Secondary outcomes were the effects of age, sex, co-morbid conditions, concomitant weight loss programs, and OSA severity on weight changes with effective CPAP therapy in OSA. RESULT(S): No baseline clinical or demographic differences were found between the two groups. There was no significant mean weight change between the compliant and noncompliant groups at one year or at two years. There was no difference in the number of subjects who lost weight between the compliant and noncompliant groups at one year (40% vs 47%, respectively) or at two years (41% vs 50%, respectively). There were no differences between the groups in co-morbid conditions (55% vs 58%, respectively) or those who participated in a weight loss program (8 vs 4, respectively). CONCLUSION(S): CPAP may not directly lead to weight loss. However, effective therapy should lead to better sleep, thus minimizing fluctuations in cytokines and improving metabolic derangements and general health. Few subjects participated in a weight loss program. With compliant CPAP use, patients should be more mentally and physically prepared to undergo a weight loss program with its additional health benefits.