Last week, we reported on an antibody that breaks down ghrelin, a known appetite stimulant. Ghrelin is in the news again - this time in the November 4, 2008 issue of the Annals of Internal Medicine, where scientists report that patients who are given an oral mimetic, or imitation, of ghrelin had increased fat-free body mass.

Growth hormone secretion and muscle mass begin to decline in mid-puberty and continue to decline throughout the remainder of life. Loss of muscle mass results in frailty, decreased function, and loss of independence, and it is attributed in large part to the reduction in growth hormone. Researchers from the University of Virginia and their colleagues studied 65 health adults over the age of 60 and randomly assigned these study participants to receive either 25 mg of a ghrelin mimetic or 25 mg of a placebo each day for 1 year. The researchers found that, after 1 year, participants who received the ghrelin mimetic had significant increases in growth hormone and fat-free mass than those who received placebo.

Given the small study size, larger studies with longer follow-up periods are needed to confirm the long-term effects of the ghrelin mimetic on elderly adults who are prone to frailty.