Objective: To investigate the correlation between serum thyroglobulin (Tg) and thyroid stimulating hormone (TSH) in populations with non-toxic goiter.
Methods: Thyroid ultrasonography was conducted, and determination of serum triiodothyronine (FT3), thyroxin (FT4), Tg, thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TGAb) and TSH, and urine iodine were carried out among 609 persons with an average age of 35.4 in Panshan county, a mild iodine-deficient area in Liaoning province, and 1136 persons aged 39.1 on average in Zhangwu county, an iodine sufficient area in Liaoning province, totally 2 320 persons.
Results: The serum TSH levels of the populations with diffuse and nodular goiter in Panshan county were (0.11 +/- 0.08) mU/L and (0.90 +/- 0.10) mU/L, significantly higher than those of the normal population in the same areas (1.33 +/- 0.04) mU/L, both P < 0.01. The serum TSH levels of the populations with diffuse and nodular goiter in Zhangwu county were (1.29 +/- 0.13) mU/L and (0.89 +/- 0.14) mU/L, significantly higher than those of the normal population in the same areas (1.74 +/- 0.04) mU/L, both P < 0.01. The serum TSH level of normal population in iodine deficient area was significantly lower than that of normal population in iodine sufficient area (P < 0.01). The serum TSH level of the normal population in Panshan County was significantly lower than that of the normal population in Zhangwu County (P < 0.01). The serum Tg level of the populations with diffuse and nodular goiter in Panshan county were (12.0 +/- 1.21) ng/L and (50.1 +/- 12.20) ng/L, significantly higher than that of the normal population in the same area (9.1 +/- 2.44) ng/L, P < 0.05 and P < 0.01. The serum Tg level of the populations with diffuse and nodular goiter in Zhangwu county were (12.4 +/- 2.11) ng/L and (61.2 +/- 11.86) ng/L, significantly higher than that of the normal population in the same area (7.7 +/- 2.3) ng/L, P < 0.05 and P < 0.01. The Tg level of the normal population in Panshan County was significantly higher than that of the normal population in Zhangwu county (P < 0.01). The Tg level was positively correlated with the thyroid volume in the nodular goiter population.
Conclusion: The occurrence of goiter is not directly related to TSH stimulation in mild iodine deficient area. Nontoxic goiter shows a thyroid autonomic function. The major cause of high serum Tg in nodular goiter may be the leakage of Tg into blood circulation caused by degeneration of large colloid follicles and destruction of follicular architecture, not the volume increase of thyroid and its autonomic function.