The relationship between iron status and thyroid hormone concentration in iron-deficient adolescent Iranian girls.
Extensive data from animal and human studies indicate that iron deficiency impairs thyroid metabolism. The aim of this study was to determine thyroid hormone status in iron-deficient adolescent girls. By stepwise random sampling from among all public high schools for girls in Lar and its vicinity in southern Iran, 103 out of 431 iron deficient subjects were selected. Urine and serum samples were collected and assayed for urinary iodine and serum ferritin, iron, total iron binding capacity (TIBC), thyroid stimulating hormone (TSH), thyroxine (T4), triiodothyronine (T3), free thyroid hormones (fT4 and fT3), triiodothyronine resin uptake (T3RU), reverse triiodothyronine (rT3), selenium and albumin concentrations. Hematological indices for iron status confirmed that all subjects were iron-deficient. There was a significant correlation between T4 and ferritin (r = 0.52, P < 0.001) and between TSH and ferritin (r = -0.3, P < 0.05). Subjects with low serum ferritin had a higher ratio of T3/T4 (r = -0.42, P < 0.01). Using stepwise regression analysis, only ferritin contributed significantly to the rT3 concentration (r = -0.35, P < 0.01). The results indicate that the degree of iron deficiency may affect thyroid hormone status in iron-deficient adolescent girls.
Eftekhari
Mohammad Hassan
MH
Department of Nutrition and Biochemistry, School of Public Health and Institute of Public Health Research, Tehran University of Medical Science, Shiraz, Iran. h_eftekhari@yahoo.com
Keshavarz
Seyed Ali
SA
Jalali
Mahmood
M
Elguero
Eric
E
Eshraghian
Mohammad R
MR
Simondon
Kirsten B
KB
D000293:Adolescent; D018798:Anemia, Iron-Deficiency / Q000097:blood* / Q000503:physiopathology; D005260:Female; D005293:Ferritins / Q000097:blood; D006801:Humans; D007455:Iodine / Q000652:urine*; D007492:Iran; D007501:Iron / Q000097:blood*; D000090463:Iron Deficiencies; D012044:Regression Analysis; D013963:Thyroid Hormones / Q000097:blood*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D013975:Thyroxine-Binding Proteins / Q000032:analysis*; D014284:Triiodothyronine / Q000097:blood; D014285:Triiodothyronine, Reverse / Q000097:blood
D013963:Thyroid Hormones; D013975:Thyroxine-Binding Proteins; D014284:Triiodothyronine; D014285:Triiodothyronine, Reverse; D013972:Thyrotropin; D005293:Ferritins; D007455:Iodine; D007501:Iron; D013974:Thyroxine