Study objective: To study the role of orexins in regulating body composition in patients with COPD.
Design: Prospective study.
Patients and measurements: We measured the plasma concentration of orexin-A in 20 patients with COPD and compared the results to those obtained from 10 age-matched control subjects. Patients with COPD were classified into two groups based on their body mass index (BMI): a normal weight (NW) group (BMI > 20) and an underweight (UW) group (BMI < 20).
Results: The plasma orexin-A level was significantly lower in patients with COPD than in control subjects. In patients with COPD, the level was significantly lower in the UW group than in the NW group. Plasma orexin-A levels significantly correlated with BMI and fat mass values, but there was no significant relationship between plasma orexin-A levels and the fat-free mass of patients with COPD.
Conclusion: These results suggest that orexin-A levels are altered with weight loss and changes in body composition in patients with COPD.