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

Area of Science:

• Endocrinology
• Clinical Chemistry

Background:

• Establishing accurate reference intervals for thyroid hormones is essential for diagnosing thyroid dysfunction.
• Previous studies have not fully characterized these intervals for Chinese populations using the Access TSH 3rd IS method.

Purpose of the Study:

• To determine reference intervals for TSH, TT4, FT4, TT3, and FT3 in a healthy Chinese population.
• To investigate the influence of age and gender on these thyroid hormone levels.

Main Methods:

• Serum samples from 313 healthy Chinese subjects were analyzed.
• Thyroid hormone concentrations were measured using the Access TSH 3rd IS assay.
• Reference intervals were established using 2.5th and 97.5th percentiles.

Main Results:

• Reference intervals were established for TSH (0.61-4.16 mIU/L), FT4 (0.67-1.11 ng/dL), FT3 (2.63-4.33 pg/mL), TT4 (5.56-11.33 μg/dL), and TT3 (0.72-1.32 ng/mL).
• Males exhibited higher FT3, TT4, and TT3 levels and lower TSH levels compared to females (P < .05).
• Individuals under 30 years old showed significantly higher FT3 levels (P < .05).

Conclusions:

• The study provides validated reference intervals for key thyroid hormones in Chinese individuals.
• Age and gender are significant factors that should be considered in the clinical evaluation of thyroid diseases.