The thyroid in ulcerative colitis and Crohn's disease. IV. Thyroid hormone binding proteins.

The thyroxine binding globulin (TBG), thyroxine binding prealbumin (TBPA), albumin, thyroxine (T(4)) and the triiodothyronine uptake test (T(3)-test) values have been estimated in serum of twenty patients with ulcerative colitis (UC) or Crohn's disease. The patient group was compared with twenty healthy control subjects matched for sex and age. The T(4) and the T(3)-test values were similar in the two groups. TBPA and albumin in serum were significantly lower, while the TBG values were significantly higher in the patients than in the controls. Treatment with corticosteroids influenced the results significantly. It is also concluded that in UC and Crohn's disease sometimes both the T(4) and the T(3)-test values can be abnormal so that misdiagnosis of hyperthyroidism is easy to make.