Iodine deficiency in a geographical area can be quantified not only by urinary iodine excretion, but by the frequency of elevated TSH-levels in newborns, too. We compared the TSH-levels obtained between 20012003 with those collected after extension of universal salt-iodization with increased iodine-content (KIO3 34±8.5 mg-/kg) in the whole country (20042006). The governmental decision was adopted in 2002, implemented in practice in December 2003, and extended only in 2004 (the iodized salt was used in 96% of households). We observed TSH-levels (10 μIU/mL (WHO-criteria) at 8.23% of 2454 newborns tested between 20012003, in comparison with the 9.91% from 555 subjects borned between 20042006. Accordingly to the upper normal TSH-level (12 μIU/mL) used at the Central Laboratory of Emergency Clinical Hospital County Mures, 6.07% and 6.31% of the newborns seen between 20012003, and 20042006, respectively, had elevated TSH-levels. The difference between the two periods was not significant. Based upon these results, County Mures can be characterized at present as a moderate/mild iodine-deficient area.
However, we observed an important change: the mean TSH-level obtained in the period of 20012003 (19.81+12.63 μIU/mL) was reduced significantly in the second period (15.63+7.35 μUI-/mL), i.e. a decrease with 4.18 μIU/mL (P=0.02). In conclusion, after increasing the iodine-content of the alimentary salt and applying the measures for the universal iodization, the incidence of elevated TSH-level did not decrease, but its mean value was reduced statistically significant, showing an impro-ve-ment of iodine supple-mentation.
While the moderate increased TSH-levels (1012 μIU/mL) are considered as indicators of the iodine deficiency, the higher concentrations ((20 μIU/mL) usually indicate the coexis-ten-ce of hypothyroidism due to reduced iodine supply. We observed an important reduction of the hypothyroidism induced by iodine-deficiency: if in the first period its incidence was 2.49%, in the second it decreased to 1.46%.