Elevated circulating level of ghrelin in cachexia associated with chronic heart failure: relationships between ghrelin and anabolic/catabolic factors.

BACKGROUND: Ghrelin is a novel growth hormone (GH)-releasing peptide, isolated from the stomach, that may also cause a positive energy balance by stimulating food intake and inducing adiposity. We sought to investigate the pathophysiology of ghrelin in the cachexia associated with chronic heart failure (CHF). METHODS AND RESULTS: Plasma ghrelin was measured in 74 patients with CHF and 12 control subjects, together with potentially important anabolic and catabolic factors, such as GH and tumor necrosis factor (TNF-alpha). Patients with CHF were divided into two groups, those with cachexia (n=28) and those without cachexia (n=46). Plasma ghrelin did not significantly differ between all CHF patients and controls (181+/-10 versus 140+/-14 fmol/mL, P=NS). However, plasma ghrelin was significantly higher in CHF patients with cachexia than in those without cachexia (237+/-18 versus 147+/-10 fmol/mL, P<0.001). Circulating GH, TNF-alpha, norepinephrine, and angiotensin II were also significantly higher in CHF patients with cachexia than in those without cachexia. Interestingly, plasma ghrelin correlated positively with GH (r=0.28, P<0.05) and TNF-alpha (r=0.31, P<0.05) and negatively with body mass index (r=-0.35, P<0.01). CONCLUSIONS: Plasma ghrelin was elevated in cachectic patients with CHF, associated with increases in GH and TNF-alpha and a decrease in body mass index. Considering ghrelin-induced positive energy effects, increased ghrelin may represent a compensatory mechanism under catabolic-anabolic imbalance in cachectic patients with CHF.