An initial investigation of the serum thyroid hormone reference range in the apparently healthy individuals of Beijing and Shanghai area of China / 中华检验医学杂志

ABSTRACT

ObjectiveTo establish the reference intervals of serum triiodothyronine (TT3),the thyroxine ( TT4 ),free triiodothyronine ( FT3 ),free thyroxine ( FT4 ) and thyroid-stimulating hormone (TSH)in the apparently healthy individuals of Beijing and Shanghai.Methods According to the requirement for laboratory support for the diagnosis and monitoring of thyroid diseases in the National Academy ofClinicalBiochemistry(NACB)laboratorymedicinepracticeguidelines, therewere 390 apparently healthy individuals tested (221 male,169 female,18 -65 years old) from Beijing and Shanghai for serum TT3,TT4,FT3,FT4 and TSH on American Beckman UniCel DXI 800 Automatic Chemiluminescent Analyzer.All markers were analyzed between gender,region,age group using t test and ANOVA.The reference intervals of all markers were determined by P2.5 - P97.5.ResultsTT3,TT4,FT3,FT4,TSH levels in the male group were ( 1.90 ± 0.32) nmol/L,( 116.77 ± 18.02) nmol/L,( 5.28 ±0.67) pmol/L,( 11.54 ± 1.97) pmol/L,( 1.92 ± 1.12 ) mIU/L,respectively,while the above indicators in the female group were ( 1.82 ± 0.32) nmol/L,( 115.73 ± 14.39 ) nmol/L,(5.04 ± 0.59 ) pmol/L,( 10.94 ± 1.45) pmol/L,( 2.37 ± 1.86 ) mIU/L,respectively.When comparing the results in genders,statistical significance was shown in TF3,FT3,FT4 and TSH of two gender groups( t =2.377,3.642,3.471,2.520,all P ＜ 0.05 ).When comparing different regions,statistical significance was only shown in FT3 ( t =6.410,P ＜ 0.05 ),in which Beijing group was (5.01 ± 0.63) pmol/L,and Shanghai group was (5.41 ±0.61 ) pmol/L,and no significant difference were shown in other four markers.Correlation analysis showed that TT4 was positively correlated with age (r =0.22,P ＜ 0.001 ) while TSH was negatively correlated with age ( r =- 0.12,P ＜ 0.05 ).TT3,TT4,FT3,FT4,TSH reference intervals were ( 1.22 - 2.50 ) nmol/L,(83.37 - 149.37 ) nmol/L,( 3.88 - 6.48 ) pmol/L,( 7.70 - 14.86) pmol/L,( 0.38 - 5.58 ) mIU/L,respectively.ConclusionDifferences of serum thyroid hormones were observed in different areas of China,It is important to establish reference intervals of the serum thyroid hormones in Chinese population.