Abstract
Rationale: Obstructive sleep apnea (OSA) is common in obesity. Leptin plays an important role in controlling appetite, energy expenditure, and body fat deposition. Studies investigating the effect of continuous positive airway pressure (CPAP) on leptin have conflicting results. The major confounder is the visceral obesity.
Objectives: We tested the stored blood from a double-blind, randomized, placebo-controlled trial aimed to (1) determine the CPAP effect on leptin and visceral fat (2) investigate if changes of visceral fat after CPAP correlated with leptin in OSA patients.
Methods: Ninety-six patients were randomized to 12-week therapeutic (n=48) or subtherapeutic (n=48) CPAP. We measured the levels of leptin from stored blood and measured visceral fat with abdominal MRI. Results were analyzed with the intention to treat. The multiple linear regression was used to measure correlation between changes of visceral fat with changes of leptin.
Results: Eighty patients completed the study and 16 withdrew. 12-week therapeutic CPAP did not modify leptin and visceral fat compared to subtherapeutic group although significant improvement of objective sleepiness. The regression analysis identified that changes of visceral fat independently correlated with changes of leptin (coefficient 1.531, P<0.001, 95% CI 0.690 to 2.305).
Conclusions: 12-week CPAP treatment does not modify leptin and visceral fat and changes in visceral fat independently correlate with changes of leptin. CPAP therapy should be combined with other measures that can reduce visceral fat when managing OSA patients.
- © 2011 ERS
