Circulating ghrelin in patients with chronic obstructive pulmonary disease

Objective Unexplained weight loss is common in patients with chronic obstructive pulmonary disease (COPD). Because ghrelin plays an important role in energy homeostasis, this study investigated the plasma level of ghrelin in COPD. Methods Plasma ghrelin levels and levels of leptin, tumor necrosis factor-α, and C-reactive protein were measured in 29 patients with COPD and 17 healthy controls. Body composition was assessed with bioelectrical impedance analysis. Results Body mass index and percentage of body fat were lower in patients who had COPD than in healthy controls. Plasma ghrelin and leptin concentrations were significantly lower in patients who had COPD than in healthy controls (ghrelin: 0.25 ± 0.22 ng/mL versus 0.43 ± 0.24 ng/mL, P = 0.013; leptin: 1.77 ± 0.70 ng/mL versus 2.85 ± 0.96 ng/mL, P = 0.000). In contrast, tumor necrosis factor-α and C-reactive protein were significantly higher in those with COPD than in controls. Plasma ghrelin (log transformed) was positively correlated with body mass index and percentage of body fat in patients with COPD but negatively correlated in control subjects. Plasma ghrelin was negatively correlated with tumor necrosis factor-α and C-reactive protein in COPD. Conclusion Plasma ghrelin level was decreased in COPD and this is different from other weight-loss diseases. These data suggest that decreased ghrelin and other factors may contribute to alterations in metabolic status during inflammatory stress in this disease.