Adult Growth Hormone Deficiency: from Transition to Senescence

The acute metabolic actions of hGH were discovered in GH-deficient adults (GHDA) 60 years ago and placebo controlled trials of prolonged rhGH replacement therapy appeared 30 years after. Untreated GHDA causes excess morbidity and mortality from cardiovascular disease and the clinical features include fatigue, reduced aerobic exercise capacity, abdominal obesity, reduced lean body mass, osteopenia, and elevated levels of circulating cardiovascular risk biomarkers. Several of these abnormalities normalize with GH replacement. Frequent side effects are fluid retention and insulin resistance, which are reversible and dose-dependent. The dose requirement declines with age and is higher in women. Continuation of GH replacement into adulthood is indicated in some patients with childhood-onset disease so the diagnosis must be reassessed. Observational data show that mortality in GH replaced patients is reduced compared to untreated patients. Thus, GH replacement in GHDA has proven beneficial and safe.