The epidemiology of iodine-deficiency disorders in relation to goitrogenic factors and thyroid-stimulating-hormone regulation.

In children aged 5-7 y from goiter-endemic areas in Ubangi, Zaire, and Ntcheu, Malawi, mean serum thyroxin (T 4 ) concentrations were 53±49 vs 81±33 nmol/L (P<0.05), and thyroid-stimulating hormone (TSH) values were 24.3±9.6 vs 4.5±3.3 mU/L respectively (P<0.01); mean urinary iodine concentrations were 0.14±0.02 vs 0.09±0.02 μmol/L, and mean thiocyanate concentrations were 0.14±0.05 vs 0.17±0.05 nmol/L, respectively (P<0.05). Mean serum selenium concentrations were 0.343±0.176 μmol/L in Ubangi and 0.437±0.178 μmol/L in Ncheu (P<0.05)