Some effects of triamcinolone pretreatment on intravenous glucose tolerance test in patients with different thyroid function.
In 42 patients (17 hypothyroid -Hypo, 14 euthyroid -Eu and 11 thyrotoxic -TX) the intravenous glucose tolerance test was performed before and after triamcinolone sensitization. The blood sugar (BS), immunoreactive insulin (IRI), growth hormone (GH), inorganic phosphorus (P), calcium (Ca), and total proteins (TP) were assessed and glucose disappearance rate was calculated from absolute values (KGt) and from increments (KGi) of glucose. Triamcinolone caused a rise of BS in Eu an Tx subgroups and a decrease of KGt and KGi in Hypo and decrease of KGt in Tx. No differences were found in patterns of IRI, GH, TP and Ca, respectively, but a significant rise of P after triamcinolone was found in Hypo and Eu subgroup. When comparing the subgroups according to thyroid function, only mild differences could be demonstrated in BS pattern both during IVGTT and TIVGTT, but significant differences of KGt and KGi were found between Eu and Hypo subgroups. No differences were observed in patterns of IRI, GH and Ca (except fasting values in Eu and Hypo subgroups during IVGTT, but significant differences were found in the pattern of P and particularly of TP. Except of differences of TP and P, changes during TIVGTT were not more pronounced than those during IVGTT. The comparison of effects of triamcinolone pretreatment on IVGTT and on OGTT (as were described previously) demonstrated similar effects of triamcinolone in Eu subgroups (significant changes of BS, IRI and P), but different action in Hypo- and Tx subgroups (where the significant changes of BS, IRI and P during OGTT and IVGTT were not parallel). These findings may suggest a possible role of some gastrointestinal and/or hepatic factors in action of triamcinolone in impaired thyroid function, but not in normal persons.