The somatopause: Should growth hormone deficiency in older people be treated?

Secretion of growth hormone (GH) by the pituitary gland progressively declines beginning in early adult life, a phenomenon which is termed 'the somatopause'. The observation that many of the changes which occur with advancing age are opposite to the physiologic effects of GH suggests the declining levels of GH and insulin-like growth factor 1 (IGF-1), the mediator of many of the actions of GH, may be responsible for some of these changes. This article reviews the current understanding of mechanisms underlying the somatopause, the changes of aging which may result from diminished activity of the GH-IGF-1 axis, the evidence which suggests that GH 'replacement therapy' may reverse these changes, ad the risks of treating somatopause with GH replacement.