Adult growth hormone deficiency.

Growth hormone (GH) has an important physiological role in adulthood.1–3 Before the 1980s anecdotal reports suggested that patients lacking GH experienced symptoms of increased fatigue and low mood, features that improved with GH replacement.4 Long-term replacement was not considered because of the lack of availability of cadaveric GH. With the development of recombinant GH in the mid-1980s, interest has been increasing in the consequences of GH deficiency (GHD) and the effects of shortand long-term replacement. Adults with hypopituitarism and GHD are both psychologically and physically less healthy than age-matched controls. This has led to the description of a specific constellation of symptoms and signs, designated the ‘adult GHD syndrome’5 which includes: • poor self-esteem • increased levels of anxiety • lack of social interaction, and • abnormalities of metabolism, body composition and bone mineralisation. There has also been considerable interest in the physiological decline in GH secretion with ageing. Integrated GH secretion decreases by approximately 14% per decade in adult life, although peak response to stimulation is still maintained. The effect of GH replacement in older patients has been examined in placebo-controlled trials, but as yet there is little evidence of consistent improvement and this issue will not be considered further here.