Changes in circulating iodothyronines in diabetics with various degrees of metabolic control

Plasma TSH, total and free T3 and T4, reverse T3, blood pH, HbAlc, ketonuria and glycosuria were evaluated in 8 subjects with diabetic ketoacidosis, in 54 diabetics of group 1 and group 2 without severe metabolic derangement and in 10 control women. The diabetics with ketoacidosis showed before intensive therapy low T3, total and free, and high reverse T3 concentrations as compared to controls (unpaired t-test, p less than 0.001). After one day of intensive therapy the decrease of hyperglycemia and pH increase (p less than 0.001, paired t-test), glycosuria and ketonuria are not related to significant variations of iodothyronines and TSH. The significant variations (paired t-test, p less than 0.001) in total and free T3 and in reverse T3 concentrations were found only six days after remission of ketoacidosis. In diabetics (type 1 and 2) without recent history of ketoacidosis no differences were found in mean total and free T3 and T4, in reverse T3 and in plasma concentrations although mean blood glucose and HbAlc were statistically different (t-test, p less than 0.001). The changes in serum T3 (total and free) and reverse T3 are useful indicators of total metabolic control during the management of diabetic ketoacidosis.