Increased plasma ghrelin level in lung cancer cachexia.

PURPOSE Ghrelin, a novel growth hormone-releasing peptide,has been shown to cause a positive energy balance by stimulating food intake and inducing adiposity. We sought to investigate the pathophysiology of ghrelin in cachexia associated with lung cancer. EXPERIMENTAL DESIGN Plasma ghrelin level was measured in 43 patients with lung cancer and 21 control subjects. Patients with lung cancer were divided into two groups: patients with cachexia (n = 21) and those without cachexia (n = 22). RESULTS Plasma ghrelin level did not significantly differ between all patients with lung cancer and controls (157 +/- 10 versus 132 +/- 8 fmol/ml, P = 0.1). However, plasma ghrelin level was significantly higher in patients with cachexia than in those without cachexia (180 +/- 17 versus 135 +/- 10 fmol/ml, P = 0.011). Furthermore, plasma ghrelin level increased significantly in patients with decreased food intake after chemotherapy (from 136 +/- 11 fmol/ml to 170 +/- 16 fmol/ml on day 8, 179 +/- 20 fmol/ml on day 21 after start of chemotherapy), although plasma ghrelin level did not significantly change in those without decreased food intake. CONCLUSIONS Baseline plasma ghrelin level was elevated in cachectic patients with lung cancer, and follow-up plasma ghrelin level increased in patients with anorexia after chemotherapy. Considering the positive energy effects induced by ghrelin, increased ghrelin may represent a compensatory mechanism under catabolic-anabolic imbalance in cachectic patients with lung cancer.