Iodine deficiency has recurred in Istanbul, Turkey

Abstract

Background: Iodine status of Turkish people improved after mandatory iodination of table salt; however there is a contrary results and difference between regions and age groups. Aim:The aim of the present study was to assess iodine status in people living in Istanbul, Turkey.Methods: This was a single center, retrospective study on subjects who attended to Acibadem Labmed Clinical Laboratories between January 2009 and December 2013 for the measurement of urinary iodine concentration (UIC). Subjects with UI and thyroid stimulating hormone (TSH) levels were included. Data on UIC was available for 1933 subjects (1629 women and 304 men).Results: Mean UIC was 123, 2 µg/g creatinine (µg/gCr) and mean age of the subjects was 36, 58 ± 0, 33 years. Mean UIC of men were lower than women (101, 55 ± 3, 95 vs 127, 24 ± 2, 22 µg/gCr; p<0.001). Totally 917 (47, 4%) of the subjects were iodine deficient (UIC < 100 µg/gCr). Men were more iodine deficient than women (59, 5% vs 45, 2%; p<0.001). Younger subjects were more iodine deficient than the older ones (p<0.001). TSH levels of iodine deficient and sufficient subjects were not different (3, 34 ± 0, 24 vs 3, 19 ± 0, 22 mIU/L; p>0, 05). There was a positive correlation between iodine level and age (r = 0, 149; p<0.03), but there was no correlation between iodine and TSH levels (p>0.05). Conclusion:A considerable number of subjects in our study had UIC below the normal ranges for adults, demonstrating that iodine deficiency continues to be a major healthcare concern in Turkey. At least, mild iodine deficiency has recurred in people living in Istanbul. The results emphasize the need for continuous monitoring in all regions, even in a country with iodine sufficiency. Keywords: Material and MethodsThis was a single center, retrospective study on subjects who attended to Acibadem Labmed Clinical Laboratories between January 2009 and December 2013 for the measurement of UIC. The Acibadem University Ethics Committee for Human Studies approved the study protocol. Subjects with urinary iodine (UI) and thyroid stimulating hormone (TSH) levels were included.Data on UIC was available for 1933 subjects (1629 women and 304 men). Data on UIC and TSH were available for 212 of these subjects. UIC were determined according to previously described method [5]. UI levels greater than 700 µg/g creatinine were eliminated from analysis because it was unclear if these samples were a result of contamination or toxicity. TSH levels were measured in C8000 Modular Analytics by using reagents from Roche Diagnostics. Repeatability CV and intermediate precision CV were determined to be ≤3,0 % and ≤ 7,2 % respectively by the manufacturer.Descriptive statistics were presented as mean ± standard error mean (SEM) for normally distributed data, and as counts and percentages for categorical data. The relationship between the categorical variables was examined using the Pearson Chisquare test; otherwise Fisher's exact test was used. The t-test or one-way Anova test was used to compare independent variables ...