Association of serum selenium with thyroxin in severely iodine-deficient young children from the Amhara region of Ethiopia.

ABSTRACT

BACKGROUND/OBJECTIVES: Selenium (Se) as part of glutathione peroxidase and iodothyronine deiodinase enzymes influences thyroid metabolism. This study investigated the association of serum Se levels with thyroid metabolism of severely iodine-deficient young children from the Amhara region of Ethiopia. SUBJECTS/METHODS: In a cross-sectional study, Se, thyroid-stimulating hormone, total thyroxin, total triiodothyronine and thyroglobulin in serum of children (N=628) 54-60 months of age from the Amhara region, Ethiopia, were analyzed. In addition, iodine in urine and household salt was analyzed, and the presence of goiter was assessed. RESULTS: The median serum Se concentration was 61.4 µg/l (10.7-290.9 µg/l). Selenium deficiency (serum Se <70 µg/l) was detected in 57.8% (N=349) of the children. The median urinary iodine concentration (UIC) was 9.8 µg/l. The majority (86.6%, N=449) of children had UIC below the recommended value (100 µg/l). In addition, 59.8% (N=310) of children were severely iodine deficient (UIC<20 µg/l). Only 12.7% of salt samples had iodine. Goiter was present in 44.6% (N=280) of the children. Selenium-deficient children had higher serum thyroxin (T4) than children with normal serum Se concentration (P<0.001). CONCLUSIONS: Serum Se was negatively associated with T4 level in young children from the Amhara region of Ethiopia and may endanger the effectiveness of the salt iodization program.