Changes in serum thyroid hormone and thyroglobulin levels after surgical treatments for toxic and non-toxic goiter.

We assessed changes in serum total tri-iodothyronine (TT3), total thyroxine (TT4), free thyroxine (FT4), reverse tri-iodothyronine (rT3), thyroid stimulating hormone (TSH), and serum thyroglobulin (hTg) levels in 20 patients with toxic diffuse goiter who received subtotal thyroidectomy after metabolic control with antithyroid drugs and 22 patients with non-toxic solitary nodular goiter who received lobectomy only. In the first 2 days postoperatively the toxic diffuse goiter group had approximately a 50% decrease in the mean serum TT3 concentration, and a 28% decrease in the mean serum TT4 concentration. In the same period, the non-toxic nodular goiter group had approximately a 30% decrease in mean serum TT3 concentration, and a 15% decrease in mean serum TT4 concentration. The toxic diffuse goiter group and the non-toxic nodular goiter group each had transient elevations of the mean serum rT3 concentration, amounting to 34% and 48% respectively. Neither group had any change in the mean serum FT4 level, while both showed a several-fold elevation of serum hTg. At the 6th week postoperatively in both groups, the mean serum TT3 level had returned to the preoperative value, the mean serum TT4, rT3 and hTg levels were significantly lower than preoperative values, and the mean serum FT4 level remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)