Age effects on growth hormone and testosterone responses to endurance exercise in patients with neuromuscular diseases

We have investigated the effect of age on the changes in growth hormone (GH) and testosterone induced by muscular exercise in patients with neuromuscular diseases, by means of a test procedure which maintained compatibility. We investigated 21 control subjects and 36 patients. We found a significant increase in GH concentrations (+329%; p<0.0001) after 20 min of exercise on a bicycle ergometer. Testosterone concentrations showed no significant change. There was a significant negative correlation between the GH level after exercise and the age of the patients (R=−0.3, p=0.015). The influence of increasing age on the GH reaction in patients with neuromuscular disease is substantial and could have a significant influence on muscle mass, muscle strength and the time at which decompensation occurs in elderly patients with neuromuscular diseases.