Recognizing Iodine Deficiency in Iodine-Replete Environments

University of Tennessee, Knoxville, Tennessee, United States
New England Journal of Medicine (Impact Factor: 55.87). 10/2007; 357(12):1263-4. DOI: 10.1056/NEJMc070196
Source: PubMed
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    ABSTRACT: Urine iodine has been measured in the U.S. population by the National Health and Nutrition Examination Survey (NHANES) since 1971. A downward trend was noted between NHANES I (320 +/- 6 microg/L in 1971-1974) and NHANES III (145 +/- 3 microg/L in 1988-1994). This report presents data from NHANES 2001-2002 that indicates that the U.S. median urine iodine (UI) level has stabilized since the initial drop between NHANES I and NHANES III. The median UI concentration in the U.S. population in NHANES 2001-2002 was found to be 167.8 microg/L (95% confidence interval [CI] 159.3-177.6). The NHANES 2001-2002 data confirm the current stability of the U.S. iodine intake and continued adequate iodine nutrition for the country.
    No preview · Article · Aug 2005 · Thyroid
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    ABSTRACT: Iodine deficiency disorders (IDD) constitute significant public health problems in parts of the world with poor iodine nutrition, but have been eradicated in North America and other regions. We herein report 3 cases of IDD, which occurred in women living in iodine-replete environments. The clinical presentation, biochemical findings, and radiological features of the patients were analyzed and presented in 3 case reports. The radiological features are illustrated in sonographic and scintigraphic images. A literature review and discussion, which highlight the risk factors, pathogenesis, ancillary investigations, and rational treatment of iodine deficiency goiter and hypothyroidism are provided. All 3 patients were young women, aged 24 to 38 years, who had goiter. Two of them presented with goitrous hypothyroidism. Radioactive iodine scintigraphy showed a characteristic finding of diffusely increased uptake (in the absence of clinical and biochemical evidence of hyperthyroidism). This scintigraphic pattern was found to be pathognomonic. Dietary iodine supplementation alone resulted in complete remission of IDD in the subjects, including the 2 patients with hypothyroidism. IDD can occur in iodine-replete environments. A high index of suspicion is needed to recognize these cases. It is pertinent that the correct diagnosis be made to avoid unwarranted life-long thyroxine therapy in patients presenting with goiter and hypothyroidism, which is easily treatable with iodized salt. These cases underscore the need for considering iodine deficiency in the etiologic diagnosis of goiter and hypothyroidism, even in iodine-sufficient regions.
    Preview · Article · Feb 2009 · The American Journal of the Medical Sciences
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    ABSTRACT: Iodine-deficiency disorders are prevalent in regions with low soil iodine levels but have generally been eliminated in the United States through the widespread use of iodized salt. We report 2 cases of iodine deficiency in minority women living in Central New Jersey. Case 1: A 29-year-old Hispanic woman presented with possible hyperthyroidism. Examination showed a diffusely enlarged thyroid gland. Thyroid function tests were normal. An I123-uptake and scan demonstrated a 24-hour uptake of 72% and a diffusely enlarged gland with no focal nodules. A 24-hour urine showed an undetectable iodine level (<10 μg). Further discussion with the patient revealed that she actively avoided consumption of iodized salt and seafood. Case 2: A 39-year-old Asian American woman presented with goiter. Examination showed a diffusely enlarged gland with some asymmetry. Thyroid function tests were normal. An I123-uptake and scan showed a 24-hour uptake of 68.8% and a diffusely enlarged gland. A 24-hour urinary iodine collection showed subnormal levels of 30 μg. Like the previous patient, this one also actively avoided iodized salt and iodine-supplemented foods. Iodine-deficiency disorders can develop in minority populations even in iodine-replete environments. A full diet history including quantification of iodized salt and supplemented food intake should be obtained routinely as a part of the evaluation of patients with goiter. Measurement of urinary iodine excretion is warranted in suspicious cases. The treatment is as simple as adding iodized salt to the diet.
    No preview · Article · Feb 2009 · The Endocrinologist
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