Trophic factor supplementation: effect on the age-associated changes in body composition.

Many of the changes in body composition associated with aging are similar to those found in states of growth hormone deficiency. Elderly people have also been found to have significant abnormalities in several trophic factor systems including growth hormone/insulin-like growth factors, and both male and female sex hormones. This has led to intense interest in the clinical effects of trophic factor supplementation in older individuals. This article reviews the age-related alterations in the growth hormone and sex steroid axes, as well as the effects of supplementation. In addition, important questions about the use of trophic factors in the elderly that must be addressed in future research are put forth.