Association between dietary iodine intake and prevalence of subclinical hypothyroidism in the coastal regions of Japan.

Konno, N; Makita, Hironi; Yuri, Kenji; Iizuka, Narushi; Kawasaki, Keitarou

doi:10.1210/jcem.78.2.8106628

Cited by 81 publications

(55 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…), topical antiseptics, and contrast dyes. In addition to the epidemiologic evidence, dinical studies have suggested a relationship of elevated iodine intake in autoimmune thyroid diseases (16)(17)(18)(19). The effects of high iodine uptake, however, are observed only in genetically susceptible individuals (20).…”

Section: Iodine As An Environmental Trigger Of Autoimmune Thyroiditismentioning

confidence: 99%

Linking iodine with autoimmune thyroiditis.

Rose

Rasooly

Saboori

et al. 1999

Environ Health Perspect

View full text Add to dashboard Cite

A great deal of circumstantial evidence has linked iodine with the rising incidence of autoimmune thyroiditis in the United States. In our investigations, we have shown directly that T cells from humans with chronic lymphocytic thyroiditis proliferate in the presence of iodinated but not in the presence of noniodinated human thyroglobulin. Moreover, the proliferative response is restored when the thyroglobulin is iodinated artificially in vitro. Using a panel of monoclonal antibodies, we found evidence that the presence of iodine induces a number of stereochemical changes in the conformation of the molecule, resulting in the loss of some antigenic determinants and the appearance of others. One prominent determinant was associated with the iodine-containing amino acid thyroxine. Both the number and position of the iodine substituents determine the precise specificity of this epitope. A new model for the study of the role of iodine in inducing thyroid autoimmunity has become available in the form of the nonobese diabetic (NOD)-H2h4 mouse. This animal develops autoimmune thyroiditis spontaneously but in relatively low prevalence. However, if iodine is added to the drinking water, the prevalence and severity of the thyroid lesions increase markedly. The immune response is specific for thyroglobulin, both in terms of the antibody response and T-cell proliferation. In fact, the appearance of lesions can be predicted by the presence of thyroglobulin-specific IgG2b antibody. The disease, moreover, can be transferred adoptively, using spleen cells from iodine-fed donors treated in vitro with iodinated thyroglobulin. The effects of iodine feeding are greater in conventional animals compared with those maintained under specific pathogen-free conditions. Based on T-cell proliferation, it appears that the NOD-H2h4 strain of mice has innately a greater response to murine thyroglobulin than do other mouse strains and that the proliferation is increased even more by feeding iodine. We suggest, therefore, that the presence of iodine increases the autoantigenic potency of thyroglobulin, a major pathogenic antigen in the induction of autoimmune thyroiditis. This animal model provides a unique opportunity for investigating in detail the mechanisms by which an environmental agent can trigger a pathogenic autoimmune response in a susceptible host.

show abstract

Section: Iodine As An Environmental Trigger Of Autoimmune Thyroiditismentioning

confidence: 99%

Linking iodine with autoimmune thyroiditis.

Rose

Rasooly

Saboori

et al. 1999

Environ Health Perspect

View full text Add to dashboard Cite

show abstract

“…Zava and Zava 7 estimated that Japanese iodine intake, which comes largely from seaweed consumption, ranges from 1 to 3 mg/day. The mean or median UIC of Japanese residents ranges from 281 to 3300 μg/L in many regions of Japan 8, 9, 10, 11, 12, 13, 14.…”

Section: Introductionmentioning

confidence: 99%

Genetic alterations of differentiated thyroid carcinoma in iodine‐rich and iodine‐deficient countries

et al. 2016

View full text Add to dashboard Cite

BRAF V600E mutation, RET rearrangements, and RAS mutations are the common genetic alterations in differentiated thyroid carcinomas derived from follicular thyroid cells. However, the relationship between these alterations and iodine intake is still controversial. To clarify the influence of iodine intake on the occurrence of differentiated thyroid carcinomas, we performed molecular analyses for two differentiated carcinomas, papillary thyroid carcinomas (PTCs) and follicular thyroid carcinomas (FTCs), from an iodine‐rich country (Japan) and an iodine‐deficient country (Vietnam). We examined 120 PTCs (67 Japanese and 53 Vietnamese) and 74 FTCs (51 Japanese and 23 Vietnamese). We carried out allele‐specific polymerase chain reaction (AS‐PCR) for BRAF V600E, PCR and direct sequencing for RAS mutations (codon 12, 13, and 61 in NRAS,HRAS, and KRAS), and RT‐PCR for RET/PTC1 and RET/PTC3. BRAF V600E was present in 55/67 (82.1%) Japanese PTCs and 44/53 (83%) Vietnamese PTCs. RET/PTC1 was identified in only one PTC from each country, and no samples had RET/PTC3. NRAS mutation was found in 17/51 (33.3%) Japanese FTCs and 4/23 (17.4%) Vietnamese FTCs. NRAS mutation was cited in codon 61 (20 cases) and codon 12 (one case). None of FTCs had KRAS or HRAS mutations. There were no significant differences in the prevalence of BRAF V600E,RET/PTC, or RAS mutations between the two countries. Our study showed no differences in genetic alterations of thyroid cancers from iodine‐rich and iodine‐deficient countries, possibly suggesting that iodine intake might not affect the genetic alterations of differentiated thyroid cancer.

show abstract

“…A few people developed goiters at this intake level (39>43). Those who ingested 3-16 mg/day iodine had a 10% incidence of goiter, but clinical hypothyroidism in this population was rare (43,44 clinically euthyroid. Assuming they ingested an average of 2 L water/day, this is the lowest documented iodine dose to produce goiter, even accounting for the lower body weight of the children.…”

Section: Thyroid Effects Of Excess Iodine Ingestionmentioning

confidence: 71%

“…Clinical hypothyroidism is rare among Japanese with endemic goiter due to long-term ingestion of excess iodine. In these cases, both thyroid function and thyroid size return to normal when excess iodine consumption is stopped, unless underlying thyroid disease is present (36,38,39,43).…”

Section: Thyroid Effects Of Excess Iodine Ingestionmentioning

confidence: 99%

Use of iodine for water disinfection: iodine toxicity and maximum recommended dose.

Backer

Hollowell

2000

Environ Health Perspect

View full text Add to dashboard Cite

Iodine is an effective, simple, and cost-efficient means of water disinfection for people who vacation, travel, or work in areas where municipal water treatment is not reliable. However, there is considerable controversy about the maximum safe iodine dose and duration of use when iodine is ingested in excess of the recommended daily dietary amount. The major health effect of concern with excess iodine ingestion is thyroid disorders, primarily hypothyroidism with or without iodine-induced goiter. A review ofthe human trials on the safety ofiodine ingestion indicates that neither the maximum recommended dietary dose (2 mg/day) nor the mum recommended duration of use (3 weeks) has a firm basis. Rather than a clear threshold response level or a linear and temporal dose-response relationship between iodine intake and thyroid function, there appears to be marked individual sensitivity, often resulting from unmasking ofunderlying thyroid disease. The use of iodine for water disinfection requires a risk-benefit decision based on iodine's benefit as a disinfectant and the changes it induces in thyroid physiology. By using appropriate disinfection techniques and monitoring thyroid finction, most people can use iodine for water treatment over a prolonged period of time. Key worni goiter, iodine, thyroid disorders, thyroid hormones, water purification, water supply.

show abstract

Association between dietary iodine intake and prevalence of subclinical hypothyroidism in the coastal regions of Japan.

Cited by 81 publications

References 22 publications

Linking iodine with autoimmune thyroiditis.

Linking iodine with autoimmune thyroiditis.

Genetic alterations of differentiated thyroid carcinoma in iodine‐rich and iodine‐deficient countries

Use of iodine for water disinfection: iodine toxicity and maximum recommended dose.

Contact Info

Product

Resources

About