Cachexia is a condition typified by wasting of fat and LBM caused by
anorexia and further endocrinological modulation of energy stores. Diseases known to cause cachectic symptoms include
cancer,
chronic kidney disease, and chronic
heart failure; these conditions are associated with increased levels of proinflammatory
cytokines and increased resting energy expenditure. Early studies have suggested the central
melanocortin system as one of the main mediators of the symptoms of
cachexia. Pharmacological and genetic antagonism of these pathways attenuates cachectic symptoms in laboratory models; effects have yet to be studied in humans. In addition,
ghrelin, an endogenous orexigenic
hormone with receptors on melanocortinergic neurons, has been shown to ameliorate symptoms of
cachexia, at least in part, by an increase in appetite via
melanocortin modulation, in addition to its anticatabolic and anti-inflammatory effects. These effects of
ghrelin have been confirmed in multiple types of
cachexia in both laboratory and human studies, suggesting a positive future for
cachexia treatments.