The pattern of growth hormone (GH) and immunoreactive insulin (IRI) secretion in response to insulin hypoglycemia, arginine infusion and oral glucose load was investigated in a group of hyperthyroid subjects. In 20 patients, compared with 20 normal controls, GH secretion was significantly reduced in response to both insulin hypoglycemia and arginine infusion. Arginine induced IRI secretion was also clearly decreased. In 10 patients who had undergone a 100 g oral glucose load, hyperglycemia failed to suppress GH levels, which increased paradoxically. Slightly impoverished IRI secretion and impaired glucose tolerance were observed in these subjects. In five patients, reexamined soon after restoration of euthyroidism, no significant changes in glucose tolerance and IRI secretion were noted; instead, a slightly improved GH response to the provocative stimuli and the restoration of a normal GH suppression by glucose were observed. The possibility is emphasized that in hyperthyroidism an enhancement of the catecholamine effect induced by thyroid hormones is involved in the diminished GH and IRI secretion.
|Number of pages||7|
|Journal||European Journal of Clinical Investigation|
|Publication status||Published - 1974|
ASJC Scopus subject areas