Women's urine iodine status and thyroid hormone level in severe iodine defiant areas in Xinjiang

ObjectiveTo investigate women's iodine nutrition and thyroid hormone levels in areas with severe iodine deficiecy in xinjiang, and provide the basis for scientific iodine supplement.

MethodsAccording to Project design of National Natural Science Foundation of China, a total of 1 003 pregnant women, lactating women and women of childbearing age were randomly included, for them were used the method for determination of iodine in urine by As³⁺-Ce⁴⁺ catalytic spectrophotometry (WS/T 107—2006), Roche (E411) analysis instrument and reagent kit for detecting thyroid hormones.

Results(1) In detecting urine iodine of 1 003 women, the median was 214.43 μg/L, and the median for pregnancy, lactation women, and childbearing age group were 183.53, 208.11, 224.68 μg/L, respectively; samples with urine iodine level below 50, 100 μg/L accounted for 5.68% and 18.14% respectively, urine iodine lower than 50, 100 and 150 μg/L in pregnant women accounted for 7.52%, 21.39% and 58.96%, respectively; within the three groups of urinary iodine less than 50 and 100 μg/L, there were no statistical differences (χ²=1.70, 0.54, χ²=2.59, 3.01). (2) The average of T₃, T₄, FT₃, FT₄, TSH were (2.14±0.57)nmol/L, (98.60±25.53)nmol/L, (4.74±1.55)pmol/L, (13.89±3.47)pmol/L and (2.93±3.48)mU/L.(3) Abnormal rate of serum free thyroxine (FT₄) was 19.82%, including 18.79% lower than limits, abnormal rate of thyroid stimulating hormone (TSH) was 16.67%, including 16.08% higher than the limits. (4) The T₃, T₄ of pregnant women group were highest, statistically significant difference was found between groups (F=137.76, P < 0.01, F=187.72, P < 0.01); the FT₃ and FT₄ of lactating group were highest, there was statistical difference between groups (F=19.28, P < 0.01, F=14.56, P < 0.01); T₃, T₄, FT₃, FT₄ were compared between groups, and there were significant differences found between pregnant women and lactating women group, and there was no difference found in TSH between groups (F=0.72, P=0.48).

ConclusionsIn Xinjiang areas with severe iodine deficiency, women are severely iodine deficient and their thyroid hormone levels are higher than the standard upper limit, so we should strengthen the monitoring of iodine to develop more scientific and reasonable iodine supplement intervention measures, to ensure that the iodine nutrition reaches an adequate level.