The relation of serum T4 and TSH with the urinary iodine excretion

Moulopoulos, D; Koutras, Demetrios A.; Mantzos, J.; Souvatzoglou, A.; Piperingos, G. D.; Karaiskos, K. S.; Makriyannis, D.; Sfontouris, J.; Moulopoulos, Spyridon D.

doi:10.1007/bf03349078

Cited by 14 publications

(12 citation statements)

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“…In the older studies, serum AAB were not routinely measured, and when measured the methods used were not as sensitive as the present RIAs. However, 60% of the prepubertal children examined in endemic goiter regions 30 years ago presented with NTG according to the same clinical criteria used in the current study (1), while AAB measured by the complement-fixation test were present in 12% of these patients (4). Nowadays, the mean NTG prevalence among schoolchildren examined in regions with a previous history of goiter endemia is only 12.5%, and the prevalence of ATG among NTG patients, with the new RIA tests, is 60%.…”

Section: Discussionmentioning

confidence: 62%

“…Although iodine-deficient areas still exist in isolated mountainous regions of Northern Greece, iodine deficiency has been reduced to a great extent during the past 30 years. Dietary iodine intake in Athens has almost quadrupled, reaching the optimum level of about 200 mg iodine/day (4). The urinary iodine excretion (UIE) in Athens was 45 mg/day in 1964 (3), 95 mg/g creatinine (Cr) in 1980 (5), and 208 mg/g Cr in 1991 (6).…”

Section: Introductionmentioning

confidence: 99%

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The predominant form of non-toxic goiter in Greece is now autoimmune thyroiditis

Doufas¹,

Mastorakos²,

Chatziioannou³

et al. 1999

European Journal of Endocrinology

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Endemic non-toxic goiter (NTG) in Greece has been attributed primarily to iodine deficiency. Thirty years ago about 60% of the prepubertal boys and girls examined in endemic goiter regions presented with NTG and among them thyroid autoimmunity was rarely detected. Although iodine supplementation has corrected this deficiency during the past 30 years, new cases of NTG still appear. To evaluate the prevalence and type of NTG and the effect of iodine supplementation on them in Greece at present, we performed two cross-sectional clinical studies and a retrospective pathology one: (i) thyroid gland volume and urinary iodine excretion (UIE) were assessed in a representative sample of 1213 schoolchildren from previously endemic and non-endemic regions; (ii) serum thyroxine, tri-iodothyronine, TSH, thyroid autoantibodies (AAB) (anti-thyroid peroxidase and anti-thyroglobulin antibodies) and UIE (in 60 patients) were measured in 300 consecutive patients with NTG from Athens and Heraklion; and (iii) we compared the prevalence of autoimmunity among fine needle aspiration smears of benign thyroid pathologies performed by the same pathologist between 1985 and 1986 (975 cases) and between 1994 and 1995 (2702 cases). We found that 12.5% of the schoolchildren examined in regions with a previous history of endemic goiter had NTG, whereas this percentage was only 1.7% in areas without such a history. In Athens (61.6%) and Heraklion (58.5%) a substantial number of NTG patients were AAB positive and biochemically hypothyroid. UIE in Athens did not differ between patients with autoimmune goiter (ATG) and simple goiter. The prevalence of autoimmune stigmata in pathology smears has increased from 5.94% (years 1985-1986) to 13.91% (years 1994-1995) (P < 0.05). We conclude that: (i) the persistence of endemic goiter in regional foci despite iodine deficiency correction suggests a possible role for a naturally occurring goitrogen; (ii) ATG is the predominant form of NTG in Greece nowadays; and (iii) the five-fold decrease in the prevalence of NTG during the past 30 years followed by the increase of ATG may support the relative character of the latter.

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Section: Discussionmentioning

confidence: 62%

Section: Introductionmentioning

confidence: 99%

The predominant form of non-toxic goiter in Greece is now autoimmune thyroiditis

Doufas¹,

Mastorakos²,

Chatziioannou³

et al. 1999

European Journal of Endocrinology

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“…Although it has been argued, on the basis of data from a very small group of subjects, that serum TSH is lowest in persons whose iodine nutrition falls within certain narrow limits (50), normal TSH levels are typically observed over a wide range of iodine intake. A study of 2,300 euthyroid subjects found that serum TSH levels were statistically indistinguishable among groups with single-sample UI concentrations of 51-100, 101-200, and 201-300 µg/g creatinine; only the group Articles • Greer et al…”

Section: Discussionmentioning

confidence: 99%

Health effects assessment for environmental perchlorate contamination: the dose response for inhibition of thyroidal radioiodine uptake in humans.

Greer

Pleus²,

Greer³

2002

Environ Health Perspect

412

575

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Application of a sensitive new detection method has revealed widespread perchlorate contamination of groundwater in the southwestern United States, typically at 0.005-0.020 mg/L (5-20 ppb). Perchlorate is a competitive inhibitor of the process by which iodide is actively transported from the bloodstream into the thyroid. This inhibitory action of perchlorate is the basis of its pharmaceutical use (in the treatment of hyperthyroidism) as well as its potential toxicity. To establish the dose response in humans for perchlorate inhibition of thyroidal iodide uptake and any short-term effects on thyroid hormones, we gave perchlorate in drinking water at 0.007, 0.02, 0.1, or 0.5 mg/kg-day to 37 male and female volunteers for 14 days. In 24 subjects we performed 8- and 24-hr measurements of thyroidal (123)I uptake (RAIU) before exposure, on exposure days 2 (E2) and 14 (E14), and 15 days postexposure (P15). In another 13 subjects we omitted both E2 studies and the 8-hr P15 study. We observed a strong correlation between the 8- and 24-hr RAIU over all dose groups and measurement days. We found no difference between E2 and E14 in the inhibition of RAIU produced by a given perchlorate dose. We also found no sex difference. On both E2 and E14, the dose response was a negative linear function of the logarithm of dose. Based on the dose response for inhibition of the 8- and 24-hr RAIU on E14 in all subjects, we derived estimates of the true no-effect level: 5.2 and 6.4 micro g/kg-day, respectively. Given default body weight and exposure assumptions, these doses would be ingested by an adult if the drinking-water supply contained perchlorate at concentrations of approximately 180 and 220 micro g/L (ppb), respectively. On P15, RAIU was not significantly different from baseline. In 24 subjects we measured serum levels of thyroxine (total and free), triiodothyronine, and thyrotropin in blood sampled 16 times throughout the study. Only the 0.5 mg/kg-day dose group showed any effect on serum hormones: a slight downward trend in thyrotropin levels in morning blood draws during perchlorate exposure, with recovery by P15.

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“…While in pregnant women the range is higher (100-200 µg/g), similar to ranges reported in iodine deficient areas (100-200 µg/g and 200-300 µg/g). 22,23 It is possible that thyroid autoregulation and a compensatory increase in serum T 3 concentrations in subjects with low iodine intake (reflected in low UI) leads to normalizing of thyroid functions in this population. Other factors (eg, selenium and vitamin deficiencies and other dietary and environmental differences from this NHANES population) might explain previous results.…”

Section: Discussionmentioning

confidence: 99%

Do Thyroxine and Thyroid-Stimulating Hormone Levels Reflect Urinary Iodine Concentrations?

Tractenberg¹,

Pezzullo²

2005

Therapeutic Drug Monitoring

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The toxicity of environmental chemicals such as nitrates, thiocynates, and perchlorates, some therapeutics, and dietary goitrogens can lower thyroidal iodine uptake and result in hypothyroidism and goiter. Iodine sufficiency, essential for normal thyroid hormone synthesis, is critical during gestation to assure that sufficient thyroxine (T 4 ) and iodine reach the developing fetus. Spot urinary iodide (UI) measurements are used globally to indicate and monitor iodine sufficiency of populations. In individuals, however, UI are not routinely measured; instead, normal serum thyroid-stimulating hormone (TSH) and T 4 concentrations serve as surrogate indicators of iodine sufficiency as well as thyroidal health. Our objective was to examine the relationship between UI concentrations and serum T 4 and TSH concentrations in individuals in an ''iodine-sufficient population.'' Using a cross-sectional sample of the US population (n = 7628) from the National Health and Nutrition Examination Survey (NHANES III;-1994) database, we examined the relationship among UI, T 4 , and TSH in pregnant and nonpregnant women and in men (15-44 years). There was a lack of relationship between UI (or UI/Cr) concentrations and serum T 4 or TSH concentrations. Therefore, TSH and T 4 are not appropriate markers of UI concentrations in this population. Monitoring the status of iodine nutrition of individuals in the United States may be important because serum TSH and T 4 concentrations do not indicate low iodine status. Keywordsurinary iodine measurements; maternal thyroxine T 4 monitoring; TSH; pregnancy; iodine deficiency; prevention of neurological damage; NHANES Iodine deficiency is the world's leading cause of preventable mental impairments. 1 In accordance with WHO/UNICEF/ICCIDD recommendations, 2 UI concentration is the major 4 The optimal level of iodine intake to prevent thyroid disease may be a relatively narrow range around the recommended daily iodine intake. 5 NIH Public AccessIodine plays a central role in thyroid physiology, being both a major constituent of thyroid hormones and a regulator of thyroid gland function. Goitrogens are substances that can decrease iodine availability or interfere with its tissue utilization. This can lead to inadequate thyroid hormone production, resulting in thyroid enlargement (goiter) and hypothyroidism. Two general categories of foods that have been associated with disrupted thyroid hormone production in humans: soybeanrelated foods containing isoflavons and cruciferous vegetables containing isothiocyanates. Environmental toxins such as nitrates, thiocynates, and perchlorates may affect the amount of iodine availability for thyroid hormone synthesis. Among the drugs that interfere with iodine uptake and hormone production are lithium carbonate, methimazole (MMI), propyl-thiouracil (PTU), β blockers such as propranolol (Inderal), metoprolol (Lopressor), phenylbutazone, calcium, and fluorides in the water supply. These may be accentuated by low dietary iodine intake.Iodine intake and excr...

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The relation of serum T4 and TSH with the urinary iodine excretion

Cited by 14 publications

References 3 publications

The predominant form of non-toxic goiter in Greece is now autoimmune thyroiditis

The predominant form of non-toxic goiter in Greece is now autoimmune thyroiditis

Health effects assessment for environmental perchlorate contamination: the dose response for inhibition of thyroidal radioiodine uptake in humans.

Do Thyroxine and Thyroid-Stimulating Hormone Levels Reflect Urinary Iodine Concentrations?

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