Effect of estrogen on the serum level of thyroglobulin

Thyroglobulin has been widely accepted as a useful parameter for monitoring the recurrence of differentiated thyroid carcinoma. In thyroid cell cultures, it has been reported that estrogen may stimulate the tgb gene which controls synthesis of thyroglobulin by the thyroid follicular cell. Since the serum estrogen levels of women fluctuate during the menstrual cycle, pregnancy and menopause, thyroglobulin may be unreliable in the follow-up of recurrence of differentiated thyroid carcinoma in females if it can be affected by estrogen in vivo. In order to clarify the effect of estrogen on thyroglobulin, the sera of 16 men, 42 women and 20 children were collected and divided into seven groups. Their serum estradiol and thyroglobulin levels were 17.7 +/- 1.8 pg/mL (mean +/- SEM) and 17.1 +/- 1.6 ng/mL, respectively in 20 children, 26.7 +/- 4.1 pg/mL and 12.9 +/- 1.2 ng/mL, respectively in 16 males, 151.6 +/- 20.4 pg/mL and 13.7 +/- 4.2 ng/mL, respectively in five females on the 10th to 14th days of the menstrual cycle, 16.7 +/- 1.8 pg/mL and 15.2 +/- 2.1 ng/mL, respectively in 12 postmenopausal females, 530.0 +/- 131.0 pg/mL and 14.2 +/- 1.8 ng/mL, respectively in eight pregnant women in the first trimester, 3613.9 +/- 1014.2 pg/mL and 12.0 +/- 1.6 ng/mL, respectively in seven pregnant women in the second trimester and 9246.0 +/- 694.5 pg/mL and 16.4 +/- 2.0 ng/mL, respectively in 10 pregnant women in the third trimester. The serum estradiol levels were significantly different (p less than 0.005) among these seven groups, but the serum thyroglobulin levels were not (p = 0.25). Therefore, serum thyroglobulin levels are not affected by estrogen.(ABSTRACT TRUNCATED AT 250 WORDS)