A study on the medical reference value of serum iodine and its correlation with thyroid function indicators in adults with normal thyroid function in Liaoning Province / 中华地方病学杂志
From February 2017 to December 2018, one subdistrict and one rural township were selected as the survey sites in the coastal area (Gaizhou City of Yingkou) and inland area (Kangping County of Shenyang) of Liaoning Province, respectively. Permanent residents aged 18 and older who have lived there for 5 years or more were selected as the survey subjects. Blood samples were collected to test the levels of serumiodine and thyroid function indicators [thyroid stimulating hormone (TSH), free triiodothyronine (FT 3), free thyroxine (FT 4), thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb)]. The percentile method was used to establish the 95% medical reference value range of serumiodine in adults with normal thyroid function, and Pearson correlation analysis was used to analyze the correlation between serumiodine and thyroid function indicators.
Results:
A total of 1 621 adults with normal thyroid function were examined, the median serumiodine was 62.0 μg/L, and the 95% medical reference value range was preliminarily determined as 37.0-103.0 μg/L. Among them, the medians serumiodine of males and females (826 and 795 cases) were 62.3 and 61.0 μg/L, respectively, and there was no significant difference between genders ( Z=- 1.26, P = 0.210). The medians serumiodine of adults in coastal and inland areas (827 and 794 cases) were 61.7 and 61.9 μg/L, respectively, and there was no significant difference between areas ( Z = - 0.16, P = 0.870). The medians serumiodine of adultsaged 18 - 29, 30 - 39, 40 - 49, 50 - 59 and 60 - 80 (385, 392, 378, 253 and 213 cases) were 61.0, 61.0, 63.0, 65.0 and 62.0 μg/L, respectively, and the difference between ages was statistically significant ( H = 14.52, P = 0.006). Pearson correlation analysis showed that serumiodine was weakly correlated with the level of FT 4 ( r = 0.17, P < 0.001), but not with the levels of TSH, TPOAb and TgAb ( P > 0.05).
Conclusions:
This study has established the medical reference value range of serumiodine in adults with normal thyroid function in Liaoning Province. Serumiodine is not correlated with the levels of TSH, TPOAb and TgAb.