Effect of growth hormone replacement on wound healing in healthy older men

The secretion of growth hormone, an important anabolic agent, declines with aging. We hypothesize that growth hormone levels (measured as insulin-like growth factor-1) correlate with postoperative tissue repair in otherwise healthy, elderly persons. The goal was to determine whether growth hormone supplementation can improve wound healing in this circumstance. We conducted a randomized controlled double-blind trial of 6 months of growth hormone replacement or placebo in 28 healthy older men (>69 years of age) with low baseline plasma insulin-like growth factor-1. Growth hormone doses were adjusted to elevate insulin-like growth factor-1 to levels expected in younger adults. Wound healing was tested by implanting 10 cm expanded polytetrafluoroethylene porous tubes for 10 days, then measuring the content of collagen (as hydroxyproline), DNA, and total protein. Hydroxyproline content was 15% greater in the wounds of the growth hormone group (n = 13) compared with the placebo group (n = 15), (4.52 +/- 0.94 versus 3.92 +/- 0.78 microg/cm; p = 0.04). Therefore, healthy older men who took growth hormone had enhanced reparative collagen deposition during the wound healing process. This action may be clinically useful after selected surgery or trauma in the elderly.