The influence of thyroid function on the diabetogenic action of triamcinolone in man. Glucose, insulin and growth hormone patterns after on oral glucose load.

In subjects with varying thyroid function (12 hypothyroid, 11 euthyroid and 12 hyperthyroid) an oral glucose tolerance test was performed without sensitization (OGTT) and after sensitizing with triamcinolone (TGTT). The blood glucose, serum immunoreactive insulin (IRI) and growth hormone (HGH) levels were assessed. In hypothyroid subjects a marked deterioration of the glucose tolerance was found during the TGTT as compared with OGTT, a reduction of the glucose disappearance index (GDI) and almost unchanged IRI values. The decrease of insulinogenic index (II) was not significant. In euthyroid subjects the decrease of glucose tolerance after triamcinolone was only mild, GDI values remained unaltered, IRI values and II increased. In hyperthyroid persons the decrease of glucose tolerance during TGTT was even less pronounced than in the euthyroid group, although the IRI value increased only on fasting. No significant differences of HGH pattern were observed in any group. In our patients the diabetogenic effect of triamcinolone was inversely related to the saturation with thyroid hormones and an increased response of insulin to glucose load was observed only in euthyroidism. In hyperthyroidism the participation of non-insular factors in the mechanism of maintaining the glucose tolerance after triamcinolone should be assumed.