6 Ageing and growth hormone status

Organic growth hormone (GH) deficiency in adults results in many adverse changes similar to the changes which occur in humans with increasing age. The secretion of GH from the anterior pituitary declines with increasing age. This observation, together with the changes in body composition associated with organic GH deficiency in adults, has led to the suggestion that the elderly without hypothalamic-pituitary disease are GH deficient and may benefit from GH therapy.

The impact of organic disease of the hypothalamic-pituitary axis in the elderly may result in a reduction in GH secretion of up to 90%. This reduction in GH secretion is sufficient to cause a fall in the serum insulin-like growth factor-1 (IGF-1) concentration, abnormal body composition and abnormal bone turnover, although bone mineral density is unaffected. These changes are distinct from those associated with the hyposomatotropism of the elderly, but are less severe than those seen in younger adults with organic GH deficiency.

In this chapter we discuss the effects of organic GH deficiency in elderly subjects and the potential effects of GH replacement therapy. We also examine the potential for GH therapy to correct some of the detrimental effects of the ageing process.