OBJECTIVE: The most accurate way to measure urinary iodine excretion in epidemiological surveys is still debated. We propose a new principle of estimating iodine excretion based on casual urine samples. MATERIAL AND METHODS: A total of 123 24 h urine samples and corresponding casual urine samples were collected from 31 subjects. Iodine excretion was expressed as 24 h iodine excretion and three different estimates: iodine concentration in the casual sample, iodine/gram creatinine in the casual sample, and the new principle-iodine/creatinine ratio in the casual sample, adjusted for expected creatinine excretion of the individual. RESULTS: All three estimates based on casual urine samples correlated significantly to 24 h values with a r (Pearson) of 0.37 for iodine concentration, 0. 61 for iodine/creatinine ratio and 0.62 for the age- and sex-adjusted iodine/creatinine ratio. The median iodine excretion in the entire group was 143 microg/day in 24 h samples, 87 microg/l as iodine concentration, 77 microg/g creatinine as iodine/creatinine ratio and 126 microg/day as age- and sex-adjusted iodine/creatinine ratio. CONCLUSION: Age- and sex-adjusted iodine/creatinine ratio is a more accurate and unbiased estimate of iodine excretion in epidemiological surveys of adults than the two most frequently used estimated: iodine concentration and iodine/gram creatinine, as these two estimates may introduce a bias depending on the composition of the investigated group. The adjusted iodine/creatinine ratio is superior to the other estimates, especially when individual estimates of 24 h iodine excretion is required or cohorts of selected groups are investigated. SPONSORSHIP: This work was supported by grants from the Medical Research Foundation Region Greater Copenhagen, Faroe Islands and Greenland; the Wedell-Wedellsborg Foundation; Musikforlaeggerne Agnes and Knut Morks Foundation.
OBJECTIVE: The most accurate way to measure urinary iodine excretion in epidemiological surveys is still debated. We propose a new principle of estimating iodine excretion based on casual urine samples. MATERIAL AND METHODS: A total of 123 24 h urine samples and corresponding casual urine samples were collected from 31 subjects. Iodine excretion was expressed as 24 h iodine excretion and three different estimates: iodine concentration in the casual sample, iodine/gram creatinine in the casual sample, and the new principle-iodine/creatinine ratio in the casual sample, adjusted for expected creatinine excretion of the individual. RESULTS: All three estimates based on casual urine samples correlated significantly to 24 h values with a r (Pearson) of 0.37 for iodine concentration, 0. 61 for iodine/creatinine ratio and 0.62 for the age- and sex-adjusted iodine/creatinine ratio. The median iodine excretion in the entire group was 143 microg/day in 24 h samples, 87 microg/l as iodine concentration, 77 microg/g creatinine as iodine/creatinine ratio and 126 microg/day as age- and sex-adjusted iodine/creatinine ratio. CONCLUSION: Age- and sex-adjusted iodine/creatinine ratio is a more accurate and unbiased estimate of iodine excretion in epidemiological surveys of adults than the two most frequently used estimated: iodine concentration and iodine/gram creatinine, as these two estimates may introduce a bias depending on the composition of the investigated group. The adjusted iodine/creatinine ratio is superior to the other estimates, especially when individual estimates of 24 h iodine excretion is required or cohorts of selected groups are investigated. SPONSORSHIP: This work was supported by grants from the Medical Research Foundation Region Greater Copenhagen, Faroe Islands and Greenland; the Wedell-Wedellsborg Foundation; Musikforlaeggerne Agnes and Knut Morks Foundation.
Authors: Gary L Francis; Steven G Waguespack; Andrew J Bauer; Peter Angelos; Salvatore Benvenga; Janete M Cerutti; Catherine A Dinauer; Jill Hamilton; Ian D Hay; Markus Luster; Marguerite T Parisi; Marianna Rachmiel; Geoffrey B Thompson; Shunichi Yamashita Journal: Thyroid Date: 2015-07 Impact factor: 6.568
Authors: Cria G Perrine; Mary E Cogswell; Christine A Swanson; Kevin M Sullivan; Te-Ching Chen; Alicia L Carriquiry; Kevin W Dodd; Kathleen L Caldwell; Chia-Yih Wang Journal: Thyroid Date: 2014-03-04 Impact factor: 6.568
Authors: Mariana Dineva; Margaret P Rayman; Deborah Levie; Mònica Guxens; Robin P Peeters; Jesus Vioque; Llúcia González; Mercedes Espada; Jesús Ibarluzea; Jordi Sunyer; Tim I M Korevaar; Sarah C Bath Journal: Eur J Nutr Date: 2019-02-08 Impact factor: 5.614