ADULT VS CHILDHOOD-ONSET GHD - IS THERE A REAL CLINICAL DIFFERENCE

As growth hormone (GH) secretion and insulin-like growth factor I (IGF -I) levels decrease with age, it is important to have reliable age- an d sex-specific control data for both GH stimulation tests and circulat ing IGF-I levels. This is particularly true for elderly patients with a history of pituitary disease but with normal production of the anter ior pituitary hormones other than GH. The potential impact of these fa ctors on GH deficiency (GHD) has led to a need for the development of reliable, sensitive and specific tests to assess GH reserve. Before st arting treatment with recombinant human GH in adults with suspected GH D, it is important to differentiate between adults with childhood onse t GHD (CO-GHD) and those with adult onset GHD (AO-GHD). Adults with un treated CO-GHD have significantly lower values for body weight, body m ass index, lean body mass and height than those with AO-GHD, while pat ients with AO-GHD show a more pronounced deviation from normal in psyc hosocial distress. Following treatment with GH, 12.5 mu g/kg/day s.c., patients with AO-GHD showed a decrease in waist/hip ratio and low-den sity lipoprotein. Quality of life, as measured using the Nottingham He alth Profile, changed significantly in both patient groups after 18 mo nths of therapy, though these results were only consistent in subjects with AO-GHD. Improvements were also reported in physical mobility and energy. Side-effects were mainly reported in patients with AO-GHD, an d this may have been due to the GH dosage being too high for older pat ients. In conclusion, CO-GHD in adults appears to be a developmental d isorder in patients who have not attained full somatic maturation. The hormonal/metabolic balance and lifestyle of these individuals have ad apted to their condition. AO-GHD is a metabolic disorder characterized by a hormonal imbalance affecting the health status, physical conditi on and quality of life of previously normal adults. (C) 1998 Churchill Livingstone.