RESUMO
Objective:To evaluate the consistency of individual iodine nutrition levels by serum iodine, plasma iodine and whole blood iodine, and to provide reference for iodine-related epidemiological investigation.Methods:Healthy adults aged 18 - 59 years were recruited from the Research Center of Environment and Health in Water Source Area of South-to-North Water Diversion of Hubei University of Medicine. Whole blood sample was collected and serum and plasma were separated. The content of iodine in serum, plasma and whole blood was determined by inductively coupled plasma mass spectrometry (ICP-MS), and the linear relationship, precision and accuracy of the standard curve of the detection method were evaluated. The difference of three kinds of blood iodine levels was analyzed by variance analysis of compatibility group design, and Passing-Bablok regression and Bland-Altman plot were used to evaluate the consistency between serum iodine and plasma iodine.Results:The linear range of iodine in serum, plasma and whole blood was 0.0 - 25.0 μg/L, and the correlation coefficients ( R2) were all > 0.999. The relative standard deviation of 8 mixed blood samples ranged from 1.9% to 4.3% ( n = 6), and the determination results of blood iodine certified standard substances were all within the reference range. The recovery rate of the added standard ranged from 99% to 106%. The iodine levels in serum, plasma and whole blood of 50 volunteers were (57.31 ± 8.06), (57.49 ± 8.50) and (33.89 ± 5.40) μg/L, respectively, and there was no statistically significant difference between serum iodine and plasma iodine ( P = 0.904). The results of Passing-Bablok regression showed that there was no statistically significant difference in bias between serum iodine and plasma iodine ( P = 0.538). The Bland-Altman plot indicated that the difference between serum iodine and plasma iodine was within the consistency limit. Conclusion:The results of plasma iodine and serum iodine are in good agreement, and plasma iodine can be used as an evaluation index of individual iodine nutrition level. But there is no consistency between whole blood iodine and serum iodine.
RESUMO
The current prevention and control strategy of iodine deficiency disorders in China is "adjust measures to local conditions, guide by classification and supplement iodine scientifically". The ultimate goal of the implementation of this prevention and control strategy is to carry out "precise iodine supplementation". However, at present, the implementation of "precise iodine supplementation" faces some difficulties, mainly how to accurately measure individual iodine nutrition. This paper discusses the current framework of iodine nutrition indicators, the advantages and disadvantages of various indicators, the gold standard for measuring the indicators, and the application scope and joint application of each indicator from three aspects: the intake of iodine, the level of iodine and the excretion of iodine.