Diagnosis of growth hormone deficiency in adults

GHD in adults is clearly more challenging to define than in children. A reference population needs to be determined that is matched for age, gender and body composition, and probably also physical conditioning and steroid hormone concentrations. The presence of other pituitary deficits is particularly helpful and suggestive - though their absence is by no means exclusive. There are a number of provocation tests of which the best now recognized is the insulin tolerance test. The plasma IGF-I concentration, if low, is useful, but could be misleading if within the normal range. IGFBP-3 is not very useful. There are several clinical symptoms of GHD in adults, the most bothersome of which as far as the patient is concerned are probably fatigue and other psychological disturbances, as well as abdominal adiposity. No single symptom is diagnostic, so they need to be considered together with the results of biochemical testing. The definition of true deficiency is not a trivial one, as the characteristic clinical features are also seen to some degree with increasing age in the general healthy population.