Growth Hormone in Thyrotoxicosis: Effect of Insulin-Induced Hypoglycemia1

The response in the plasma growth hormone (HGH) level to the stimulus of insulin-induced hypoglycemia has been compared in a group of 5 thyrotoxic patients with the response in a group of normal subjects. HGH was measured by radioimmunoassay. The 5 thyrotoxic patients showed a markedly impoverished response of HGH compared to the controls, peak HGH levels at 60 min after insulin being 4.5±1.5 mμg/ml in the thyrotoxic group, and 28.6 ± 5.6 in the normal subjects (mean ± sem). The HGH response of 3 normal subjects studied before and after 1 week's therapy with 200 μg triiodothyronine daily was unaltered.