Endocrine Abstracts

Introduction: The urinary iodine excretion (UIE) from fasting morning urine sample is a good epidemiologic indicator for iodine state, used in populational groups (schoolchildren, pregnant women) at risk to develop iodine deficiency disorders. It is not adequate to evaluate individual iodine intake. In pregnant women, especially with chronic autoimmune thyroiditis, it is important to estimate iodine state.

Objectives: To evaluate the individual iodine state in pregnant women comparing UIE from morning and 24-hours urine samples.

Material and methods: 24-h UIE was determined in 23 pregnant women, and the values expressed in μg/l and μg/g-creatinine were compared to each other. Morning UIE was additionally assessed in 11 women, and compared to the 24-hours UIE levels.

Results: The mean 24-hours UIE was 157.64±69.50 μg/l, with 44% lower than 273.53±121.76 μg/g-creatinine (P=0.0003, 95% CI=56.96–174.80). The individual values expressed in μg/l and μg/g-creatinine were in concordance in most of the cases (87%), both being normal or both being reduced. In three women (13%) the 24-hours UIE in μg/l suggested iodine deficiency, while the values in μg/g-creatinine indicated normal iodine intake. In the 11 pregnant women the mean morning UIE was 155.36±75.87 μg/l, similar with the 24-hours UIE μg/l (156.7±60.69), but with 30.4% lower than the 24-hours UIE μg/g-creatinine (225.29±86.74, P=0.0578). In nine cases (81.8%) all the three UIE values (morning UIE, 24-hours UIE μg/l, 24-hours UIE μg/g-creatinine) indicated concordantly iodine deficiency or normal iodine intake, in the other two (18.2%) the different UIE suggested different iodine state.

Conclusions: Important differences were observed between the morning UIE, 24-hours UIE in μg/l, 24-hours UIE in μg/g-creatinine, however the interpretation of these were mostly in concordance (87%). In 13% the results could not clearly show iodine state. Project no. 34/2013 financially supported by the internal research grants from the University of Medicine and Pharmacy Tirgu-Mures, Romania.

Disclosure: This work was supported by the Internal Research Grants of University of Medicine and Pharmacy Tirgu Mures, Romania (grant number 34/2013).