Growth hormone secretion in the elderly: ageing and the somatopause

The syndrome associated with lack of growth hormone (GH) in adults can be reversed by treatment with recombinant human GH (rhGH) with apparently beneficial clinical effects. This syndrome is strikingly similar to the characteristics of normal older adults which are known as the somatopause. GH secretion and insulin-like growth factor I levels are reduced in healthy older people and it has been suggested that the somatopause is an age-related GH deficiency state. This review describes the physiological control of GH secretion in adults and seeks an explanation for the age-related decline, considering the impact of other factors such as nutrition and mobility, and particularly whether exercise offers a physiological approach to changing both the GH decline and the somatopause. The benefits and side-effects of treatment with rhGH for normal older people or older patients facing catabolic stresses are reviewed together with alternative approaches to stimulate GH such as GH-releasing hormone and the new pharmaceutical GH secretagogues.