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Quantification of urinary iodine: a need for revised thresholds

European Journal of Clinical Nutrition volume 57, pages 1181–1188 (2003)Cite this article

Abstract

Objective: To compare different possibilities of reporting the iodine supply in the same urine samples. Indeed, in field studies, urinary iodine concentration (I/L: μg I/L, μmol I/L, I/creatinine: μg I/g creatanine, μmol I/mol creatinine) is more readily available than excretion (I/24h μg I/24 h, μmol I/24h). However, confusion exists regarding the comparability of iodine supply based upon I/L, I/creatinine and I/24h, which for decades have been regarded as biochemically equivalent.

Design: We compared I/24h, I/L and I/creatinine in accurate 24 h collections of urine and I/L and I/creatinine in 47 spot urine samples.

Patients: A total of 13 subjects (Bern n=7, Brussels n=6) collected a total of 110 precise 24 h urine collections (Bern n=63, Brussels n=47). The subjects from Brussels also took a spot sample at the beginning of each 24 h collection.

Results: Iodine supply in both places was mildly deficient according to the criteria of WHO; all but one collection indicated an intake of >0.39 μmol I/24h (>50 μg I/24h). The same data presented as I/creatinine (or I/L) indicated an iodine intake of <0.39 (<50 μg I/24h) in 5% (24%) of the samples in Bern and 23% (57%) in Brussels. Similar findings were observed for 47 spot samples. Whatever the cut-off selected, I/creatinine and I/L were systematically lower than I/24h (P<0.0002). Creatinine showed smaller CV than volume but did not perform better in defining iodine intake.

Conclusions: Considering I/24h as a reference, both I/creatinine and I/L clearly underestimate the iodine intake in subjects with adequate proteoenergetic intake. The significant deviations observed illustrate the urgent need for establishing separate ranges for I/24h, I/creatinine and I/L. In population studies, these deviations might even be larger.

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References

  • Als C, Haldimann M, Bürgi E, Donati F, Gerber H & Zimmerli B (2003): Swiss pilot study of individual seasonal fluctuations of urinary iodine concentration over two years: is age-dependency linked to the major source of dietary iodine? Eur. J. Clin. Nutr. 57, 636–646.

    Article  CAS  Google Scholar 

  • Als C, Helbling A, Peter K, Haldimann M, Zimmerli B & Gerber H (2000): Urinary iodine concentration follows a circadian rhythm. A study with 3,023 spot urine samples in adults and children. J. Clin. Endocrinol. Metab. 85, 1367–1369.

    CAS  PubMed  Google Scholar 

  • Als C, Lauber K, Brander L, Lüscher D & Rösler H (1995): The instability of dietary iodine supply over time in an affluent society. Experientia (Basel) 6, 623–633.

    Article  Google Scholar 

  • Als C, Lüscher D, Gerber H, Brander L, Lauber K & Rösler H (1997): Warum besteht erneut und noch immer Jodmangel in der Region Bern? Schweiz. Med. Wochenschr. 127, 18–22.

    CAS  PubMed  Google Scholar 

  • Beckers C, Ermans A, De Nayer P, Delange F, Glinoer D & Bourdoux P (1993): Status of iodine nutrition and thyroid function in Belgium. In Iodine Deficiency in Europe. A Continuing Concern, eds F Delange, JT Dunn & D Glinoer, pp 359–362. New York, London: Plenum Press.

    Chapter  Google Scholar 

  • Bourdoux P (1988): Measurement of iodine in the assessment of iodine deficiency. IDD Newslett., 4, 8–12.

    Google Scholar 

  • Bourdoux P (1993): Biochemical evaluation of iodine status. In Iodine Deficiency in Europe. A Continuing Concern, eds F Delange, JT Dunn & D Glinoer, pp 119–125. New York, London: Plenum Press.

    Chapter  Google Scholar 

  • Bourdoux P (1998): Evaluation of the iodine intake: problems of the iodine/creatinine ratio—comparison with iodine excretion and daily fluctuations of iodine concentration. Exp. Clin. Endocrinol. Diabetes 106(Suppl. 3) S17–S20.

    CAS  PubMed  Google Scholar 

  • Bourdoux P, Delange F, Filetti S, Thilly C & Ermans, AM (1985): Reliability of the iodine/creatinine ratio: a myth? In Thyroid Disorders Associated with Iodine Deficiency and Excess, eds R Hall & J Köbberling, pp. 145–152; Serono Symposia, No. 22. New York: Raven Press.

    Google Scholar 

  • Brander L (1997): Jodausscheidung bei schwangeren Frauen im Kanton Bern. MD Thesis, University of Bern, Bern, Switzerland.

  • Bürgi H (1993): Iodine deficiency disorders. Acta Endocrinol. 129, 487–488.

    Article  Google Scholar 

  • Bürgi H, Portmann L, Podoba J, Vertongen F & Srbecky M (1999): Thyroid volumes and urinary iodine in Swiss schoolchildren, 17 years after improved prophylaxis of iodine deficiency. Eur. J. Endocrinol. 140, 104–106.

    Article  Google Scholar 

  • Bürgi H, Supersaxo Z & Selz B (1990): Iodine deficiency diseases in Switzerland one hundred years after Theodor Kocher's survey: a historical review with some new goitre prevalence data. Acta Endocrinol. 123, 577–590.

    Article  Google Scholar 

  • Delange F (1993): Requirements of iodine in humans. In Iodine Deficiency in Europe. A Continuing Concern, eds F Delange, JT Dunn & D Glinoer, pp. 5–16, New York, London: Plenum Press.

    Chapter  Google Scholar 

  • Delange F, Benker G, Caron Ph, Eber O, Ott W, Peter F, Podoba J, Simescu M, Szybinsky Z, Vertongen F, Vitti P, Wiersinga W & Zamrazil V (1997): Thyroid volume and urinary iodine in European schoolchildren: standardization of values for assessment of iodine deficiency. Eur. J. Endocrinol. 136, 180–187.

    Article  CAS  Google Scholar 

  • Follis RH, Vanprava K & Damrongsakdi D (1962): Studies on iodine nutrition in Thailand. J. Nutr. 76, 159–173.

    Article  Google Scholar 

  • Fuller NJ & Elia M (1988): Factors influencing the production of creatinine: implications for the determination and interpretation of urinary creatinine and creatine in man. Clin. Chim. Acta 175, 199–210.

    Article  CAS  Google Scholar 

  • Haldimann M, Zimmerli B, Als C & Gerber H (1998): Direct determination of urinary iodine by inductively coupled plasma mass spectrometry uisng isotope dilution with iodine-129. Clin. Chem. 44, 817–824.

    CAS  PubMed  Google Scholar 

  • Jaffé M (1886): Über den Niederschlag, welche Pikrinsäure in normalem Harn erzeugt und über eine neue Reaktion des Kreatinins. Hoppe-Seyler's Z. Physiol. Chem. 10, 391–400.

    Google Scholar 

  • Jolin T & Escobar del Rey F (1965): Evaluation of iodine/creatinine ratios of casual samples as indices of daily urinary iodine output during field studies. J. Clin. Endocrinol. Metab. 25, 540–542.

    Article  CAS  Google Scholar 

  • Joossens JV, Claessens J, Geboers J & Claes JH (1980): 3. Electrolytes and creatinine in multiple 24-hour urine collections (1970–1974). In Epidemiology of Arterial Blood Pressure, eds H Kesteloot & JV Joossens, pp. 45–63. The Hague/Boston/London: Martinus Nijhoff Publishers.

    Chapter  Google Scholar 

  • Konno N, Yuri K, Miura K, Kumagai M & Murakami S (1993): Clinical evaluation of the iodide/creatinine ratio of casual urine samples as an index of daily iodide excretion in a population study. Endocr. J. 40, 163–169.

    Article  CAS  Google Scholar 

  • Lauber K (1975): Iodine determination in biological material. Kinetic measurement of the catalytic activity of iodide. Anal. Chem. 47, 769–771.

    Article  CAS  Google Scholar 

  • Sandell EB & Kolthoff JM (1937): Micro-determination of iodine by a catalytic method. Mikrochem. Acta 1, 9–25.

    Article  CAS  Google Scholar 

  • Solca B & Gerber H (1996): Jodversorgung in verschiedenen Regionen der Schweiz: ein Vergleich zwischen Stadt und Land in den Kantonen Bern und Tessin. Schweiz. Med. Wochenschr. 126(Suppl 74/I), 11S (abstract).

    Google Scholar 

  • Spierto FW, Hannon WH, Gunter EW & Smith SJ (1997): Stability of urine creatinine. Clin. Chim. Acta 264, 227–232.

    Article  CAS  Google Scholar 

  • Truong TH, Gerber H, Haenel A & Bürgi H (1997): Jodversorgung in verschiedenen Lebensphasen und sonographische Schilddrüsenvolumina bei Schulkindern in einer Gegend der Schweiz. Schweiz. Med. Wochenschr. 127, 715–721.

    Google Scholar 

  • Vought RL, London WT, Brown FA, Eckloff JC & Murphy RS (1964): Iodine intake and excretion in healthy non-hospitalized subjects. Am. J. Clin. Nutr. 15, 124–132.

    Article  CAS  Google Scholar 

  • Vought RL, London WT, Lutwak L & Dublin TD (1963): Reliability of estimates of serum inorganic iodine and daily fecal and urinary iodine excretion form single casual specimens. J. Clin. Endocrinol. Metab. 23, 1218–1228.

    Article  CAS  Google Scholar 

  • WHO (1994): Indicators for assessing iodine deficiency disorders and their control through salt iodization. WHO/NUT/94.6. Geneva: WHO.

  • WHO/NHD/01 (2001): Assessment of iodine deficiency disorders and monitoring their elimination. In A Guide for Programme Managers, ed. WHO, 2nd Edition. Geneva: ICCIDD/Unicef/WHO Publisher.

  • Wolff J & Chaikoff IL (1948): Plasma inorganic iodide as homeostatic regulator of thyroid function. J. Biol. Chem. 174, 555–564.

    CAS  PubMed  Google Scholar 

  • Wüthrich Ch (1995): Jodresorption bei der Mundspülung mit standardisierter PVP-Jod-Lösung unter besonderer Berücksichtigung des Gehalts an Jodid und Jodat. Dr Pharmacy Thesis, University of Bern, Bern, Switzerland.

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Acknowledgements

This work was supported by grants from the ‘Swiss National Foundation for Scientific Research’, the ‘Fondation Genevoise de Bienfaisance V. Rossi di Montelera’ and the ‘Schüpbach Foundation’. The Fonds de la Recherche Scientifique Médicale Belge (Convention n° 3.4505.97 to P.B.) also supported it.

Presented in part at the 24th annual meeting of the European Thyroid Association (ETA) in Munich, Germany, on 2 September 1997 (Als et al, 1997) and at the 12th IFCC European Congress of Clinical Chemistry in Basel, Switzerland, on 29 August 1997 (Als et al, 1997, The Official Publication of Medlab 97. Proceedings of the European Congress of Clinical Chemistry 1997, 285.)

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Authors and Affiliations

  1. Institute of Pathology, Inselspital, University of Bern, Bern, Switzerland

    C Als

  2. Institute of Clinical Chemistry, Inselspital, University of Bern, Bern, Switzerland

    C Als & H Gerber

  3. Institute of Nuclear Medicine, Clinique Ste Thérèse, Luxembourg, Luxembourg

    C Als

  4. Institute of Social and Preventive Medicine, Inselspital, University of Bern, Bern, Switzerland

    C Minder

  5. Laboratory of Clinical Chemistry-Centre Hospitalier Universitaire Brugmann, Brussels, Belgium

    D Willems

  6. Laboratory of Pediatrics, Université Libre de Bruxelles, Brussels, Belgium

    H V Van Thi & P Bourdoux

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  1. C Als
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Contributions

Guarantors: PP Bourdoux, Dr C Als.

Contributors: CA was involved in conception and design of the study, acquisition and collection of data, analysis and interpretation of data, and in writing and revising the article; CM performed analysis and interpretation of data, writing the article, and revising the article; DW was involved in acquisition and collection of data, interpretation of data; HVVT in the acquisition and collection of data, analysis of data, interpretation of data, writing and revising the article; HG in the conception and design of the study, interpretation of data, revising the article; and PB was involved in conception and design of the study, acquisition and collection of data, analysis and interpretation of data, writing and revising the article.

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Correspondence to P Bourdoux.

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Als, C., Minder, C., Willems, D. et al. Quantification of urinary iodine: a need for revised thresholds. Eur J Clin Nutr 57, 1181–1188 (2003). https://doi.org/10.1038/sj.ejcn.1601740

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