BACKGROUND: Current reference values for thyroid function tests are based on data from different ethnicities and geographical areas. The aim of the present study was to determine reference intervals for thyrotropin (TSH) and free T4 (FT4), based on the criteria of the National Academy of Clinical Biochemistry (NACB) in an Iranian population. MATERIAL AND METHODS: This study was conducted within the framework of Tehran Thyroid Study (TTS), an ongoing prospective cohort of 5704 randomly selected individuals, age ≥ 20 yr. A total of 2199 individuals (43.3% male, 56.7% female), based on NACB criteria were included in this study. Reference limit analysis was performed for the negative thyroid peroxidase antibody (TPOAb) group. RESULTS: After applying all exclusion criteria except TPOAb positivity (10.5%), data of 2459 participants remained for analysis. Of these, 953 (43.3%) were males and 1246 (56.7%) were females; the mean ± SD age was 43.53 ± 14.16 yr. The mean ± SD and median+IQR for TSH were 1.77 mU/l ± 1.24 and 1.46 (0.93-2.23) mU/l, respectively. The 2.5th and 97.5th percentiles TSH were 0.32 mU/l and 5.06 mU/l respectively. The mean ± SD and median (IQR) for FT4 for all negative TPOAb subjects were 1.19 ± 0.16 and 1.18 (1.08-1.31) ng/dl respectively. CONCLUSION: Reference ranges for thyroid function tests need to be derived from national databases. This study determined age and sex specific TSH and FT4 reference ranges in a Tehranian population, which could eventually enable clinicians to classify patients more appropriately.
BACKGROUND: Current reference values for thyroid function tests are based on data from different ethnicities and geographical areas. The aim of the present study was to determine reference intervals for thyrotropin (TSH) and free T4 (FT4), based on the criteria of the National Academy of Clinical Biochemistry (NACB) in an Iranian population. MATERIAL AND METHODS: This study was conducted within the framework of Tehran Thyroid Study (TTS), an ongoing prospective cohort of 5704 randomly selected individuals, age ≥ 20 yr. A total of 2199 individuals (43.3% male, 56.7% female), based on NACB criteria were included in this study. Reference limit analysis was performed for the negative thyroid peroxidase antibody (TPOAb) group. RESULTS: After applying all exclusion criteria except TPOAb positivity (10.5%), data of 2459 participants remained for analysis. Of these, 953 (43.3%) were males and 1246 (56.7%) were females; the mean ± SD age was 43.53 ± 14.16 yr. The mean ± SD and median+IQR for TSH were 1.77 mU/l ± 1.24 and 1.46 (0.93-2.23) mU/l, respectively. The 2.5th and 97.5th percentiles TSH were 0.32 mU/l and 5.06 mU/l respectively. The mean ± SD and median (IQR) for FT4 for all negative TPOAb subjects were 1.19 ± 0.16 and 1.18 (1.08-1.31) ng/dl respectively. CONCLUSION: Reference ranges for thyroid function tests need to be derived from national databases. This study determined age and sex specific TSH and FT4 reference ranges in a Tehranian population, which could eventually enable clinicians to classify patients more appropriately.
Authors: Zubair Baloch; Pierre Carayon; Bernard Conte-Devolx; Laurence M Demers; Ulla Feldt-Rasmussen; Jean-François Henry; Virginia A LiVosli; Patricia Niccoli-Sire; Rhys John; Jean Ruf; Peter P A Smyth; Carole A Spencer; Jan R Stockigt Journal: Thyroid Date: 2003-01 Impact factor: 6.568
Authors: M L Tanda; E Piantanida; A Lai; V Lombardi; I Dalle Mule; L Liparulo; N Pariani; L Bartalena Journal: Horm Metab Res Date: 2009-04-02 Impact factor: 2.936
Authors: Gil Atzmon; Nir Barzilai; Joseph G Hollowell; Martin I Surks; Ilan Gabriely Journal: J Clin Endocrinol Metab Date: 2009-01-21 Impact factor: 5.958
Authors: Rudolf Hoermann; John E M Midgley; Rolf Larisch; Johannes W Dietrich Journal: Front Endocrinol (Lausanne) Date: 2016-11-07 Impact factor: 5.555