Reference intervals for thyroid-stimulating hormone and thyroid hormones using the access TSH 3rd IS method in China

Abstract

Background: To calculate the reference intervals for thyroid-stimulating hormone (TSH) and thyroid hormones using the Access TSH 3rd IS method and evaluate the differences between age and genders in Chinese populations. Methods: This study collected 349 serum samples of healthy subjects were from Shengli Oilfield Central Hospital in China. Subjects who tested positive for thyroid peroxidase antibody or thyroglobulin antibody were excluded. Accordingly, 313 subjects were included for establishing reference intervals for the thyroid hormones. The serum concentrations of TSH, total and free thyroxine (TT4 and FT4), and total and free triiodothyronine (TT3 and FT3) were measured using the Access TSH 3rd IS method. The 2.5th and 97.5th percentiles or mean with standard deviation were calculated as the reference interval as appropriate. Results: The reference intervals for TSH, FT4, FT3, TT4, and TT3 calculated in present study were 0.61-4.16 mIU/L, 0.67-1.11 ng/dL, 2.63-4.33 pg/mL, 5.56-11.33 μg/dL, and 0.72-1.32 ng/mL, respectively. The FT3, TT4, and TT3 levels in males were significantly higher than in females (P