ONE OF THE EFFECTS OF THE THYROID HORMONE IS TO LOWER ADRENALINE AND CORTISOL, WHICH LOWERS GLYCEMIA:

Biull Eksp Biol Med 1982 Jun;93(6):47-49
[Hypoglycemic effect of excess thyroid hormones in insulin deficiency].
[Article in Russian]
Kandror VI, Kriukova IV, Zin’ko NV

In experiments on rats with severe streptozotocin diabetes, administration of high doses of L-thyroxine reduces hyperglycemia and glucosuria. It is postulated that glucose utilization by extrahepatic tissues does not depend on direct insulin action and that the Randle cycle is ineffective in hypermetabolism.