scholarly journals Longitudinal Study of Thyroid Hormones between Conventional and Organic Farmers in Thailand

Toxics ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 82
Author(s):  
Noppanun Nankongnab ◽  
Pornpimol Kongtip ◽  
Nichcha Kallayanatham ◽  
Ritthirong Pundee ◽  
Jutharak Yimsabai ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Longitudinal Impact ◽  
Free Triiodothyronine ◽  
Hormone Levels ◽  
Endocrine Disrupting ◽  
Organic Farmers ◽  
Thyroid Hormone Levels ◽  
The Impact

Many pesticides are endocrine-disrupting chemicals that can interfere with hormone levels. This study aimed to assess the longitudinal impact of exposure to pesticides on thyroid hormone levels, including Thyroid Stimulating Hormone (TSH), Free Triiodothyronine (FT3), Free Thyroxine (FT4), Triiodothyronine (T3), and Thyroxine (T4). Both conventional (i.e., pesticide using) and organic farmers were interviewed using questionnaires, and blood samples were collected at 7–9 a.m. to determine thyroid hormone levels for four rounds, with a duration of eight months between each round. A linear mixed model of the natural log of the individual hormone levels used random intercepts for subjects while controlling gender, baseline age, and body mass index (BMI) was used to compare between conventional and organic farmers or the impact of cumulative days of spraying insecticides, herbicides or fungicides. The estimated marginal means of the thyroid hormone levels (TSH, FT3, T3, and T4) estimated from the linear mixed models were significantly higher among the conventional farmers than organic farmers. As cumulative spray days of insecticide, herbicide or fungicide increased, TSH and FT3 increased significantly. FT4 decreased significantly as cumulative spray days of insecticide or fungicide increased. These findings suggest that the insecticides, herbicides, and fungicides sprayed by conventional farmers exert endocrine-disrupting activities, altering the hypothalamic-pituitary-thyroid (HPT) axis homeostasis.

scholarly journals Effects of Substitution and High-Dose Thyroid Hormone Therapy on Deiodination, Sulfoconjugation, and Tissue Thyroid Hormone Levels in Prolonged Critically Ill Rabbits

Endocrinology ◽  
2008 ◽  
Vol 149 (8) ◽  
pp. 4218-4228 ◽  
Author(s):  
Yves Debaveye ◽  
Björn Ellger ◽  
Liese Mebis ◽  
Theo J. Visser ◽  
Veerle M. Darras ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Hormone Therapy ◽  
Critically Ill ◽  
Kidney Tissue ◽  
High Dose ◽  
Reverse T3 ◽  
Hormone Levels ◽  
Liver And Kidney ◽  
Thyroid Hormone Levels ◽  
The Impact

To delineate the metabolic fate of thyroid hormone in prolonged critically ill rabbits, we investigated the impact of two dose regimes of thyroid hormone on plasma 3,3′-diiodothyronine (T2) and T4S, deiodinase type 1 (D1) and D3 activity, and tissue iodothyronine levels in liver and kidney, as compared with saline and TRH. D2-expressing tissues were ignored. The regimens comprised either substitution dose or a 3- to 5- fold higher dose of T4 and T3, either alone or combined, targeted to achieve plasma thyroid hormone levels obtained by TRH. Compared with healthy animals, saline-treated ill rabbits revealed lower plasma T3 (P = 0.006), hepatic T3 (P = 0.02), and hepatic D1 activity (P = 0.01). Substitution-dosed thyroid hormone therapy did not affect these changes except a further decline in plasma (P = 0.0006) and tissue T4 (P = 0.04). High-dosed thyroid hormone therapy elevated plasma and tissue iodothyronine levels and hepatic D1 activity, as did TRH. Changes in iodothyronine tissue levels mimicked changes in plasma. Tissue T3 and tissue T3/reverse T3 ratio correlated with deiodinase activities. Neither substitution- nor high-dose treatment altered plasma T2. Plasma T4S was increased only by T4 in high dose. We conclude that in prolonged critically ill rabbits, low plasma T3 levels were associated with low liver and kidney T3 levels. Restoration of plasma and liver and kidney tissue iodothyronine levels was not achieved by thyroid hormone in substitution dose but instead required severalfold this dose. This indicates thyroid hormone hypermetabolism, which in this model of critical illness is not entirely explained by deiodination or by sulfoconjugation.

scholarly journals Thyroid testing paradigm switch from thyrotropin to thyroid hormones—Future directions and opportunities in clinical medicine and research

Endocrine ◽  
2021 ◽  
Vol 74 (2) ◽  
pp. 285-289
Author(s):  
Stephen P. Fitzgerald ◽  
Nigel G. Bean ◽  
James V. Hennessey ◽  
Henrik Falhammar
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Dysfunction ◽  
Clinical Medicine ◽  
Older Individuals ◽  
Free Triiodothyronine ◽  
Thyroid State ◽  
Peripheral Tissues ◽  
Hormone Levels ◽  
Thyroid Hormone Levels ◽  
Tsh Levels

Abstract Purpose Recently published papers have demonstrated that particularly in untreated individuals, clinical parameters more often associate with thyroid hormone, particularly free thyroxine (FT4), levels than with thyrotropin (TSH) levels. Clinical and research assessments of the thyroid state of peripheral tissues would therefore be more precise if they were based on FT4 levels rather than on TSH levels. In this paper we describe implications of, and opportunities provided by, this discovery. Conclusions The FT4 level may be the best single test of thyroid function. The addition of free triiodothyronine (FT3) and TSH levels would further enhance test sensitivity and distinguish primary from secondary thyroid dysfunction respectively. There are opportunities to reconsider testing algorithms. Additional potential thyroidology research subjects include the peripheral differences between circulating FT4 and FT3 action, and outcomes in patients on thyroid replacement therapy in terms of thyroid hormone levels. Previously performed negative studies of therapy for subclinical thyroid dysfunction could be repeated using thyroid hormone levels rather than TSH levels for subject selection and the monitoring of treatment. Studies of outcomes in older individuals with treatment of high normal FT4 levels, and pregnant women with borderline high or low FT4 levels would appear to be the most likely to show positive results. There are fresh indications to critically re-analyse the physiological rationale for the current preference for TSH levels in the assessment of the thyroid state of the peripheral tissues. There may be opportunities to apply these research principles to analogous parameters in other endocrine systems.

Thyroid hormone levels in Tortoises (Testudo spp.) depending on Season and Sex

2021 ◽  
Author(s):  
Christoph Leineweber ◽  
Sabine Öfner ◽  
Karina Mathes ◽  
Hans-Peter Piepho ◽  
Rachel E. Marschang ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Rank Correlation ◽  
Information Criterion ◽  
Reference Intervals ◽  
Free Triiodothyronine ◽  
Seasonal Differences ◽  
Hormone Levels ◽  
Testudo Graeca ◽  
Thyroid Hormone Levels

Thyroid hormones and the factors influencing them are rarely studied in tortoises. This study therefore aimed to calculate reference intervals (RI) for specific species, sexes, and seasons for thyroid hormones and iodine levels in blood of four adult Mediterranean tortoise species and to evaluate possible correlations between thyroid hormones, serum iodine, plasma protein and increased liver and kidney values. Thyroid hormones (total tetraiodothyronine [tT4], free tetraiodothyronine [fT4], total triiodothyronine [tT3], and free triiodothyronine [fT3]) were measured in plasma from adult, healthy Hermann´s (Testudo hermanni, n = 255), spur-thighed (Testudo graeca, n = 89), marginated (Testudo marginata, n = 72), and Russian tortoises (Testudo horsfieldii, n = 30). Species, sex and season specific variations were determined by Bayesian information criterion (BIC) and correlations between plasma thyroid hormones, protein, iodine and increased liver/kidney values were evaluated by Spearman’s rank correlation test. Total T4 did not reveal any species, sex, or seasonal differences (RI 0.102 to 0.455 µg/dL), while seasonal differences were found for fT4 (RI spring 0.624 to 9.012; summer 0.379 to 5.476; fall 0.376 to 5.426 pmol/L). The tT3 levels differed significantly depending on species, season, and the interaction of species x season. Seasonal differences were also found for fT3 and iodine. Several significant (p < 0.05) correlations were detected between the tested analytes, especially positive correlations between tT4 and fT4. These results provide a tool for the evaluation of thyroid hormone levels in Mediterranean tortoises and indicate the influence of season on the thyroid in these animals.

scholarly journals The impact of thyroid hormone dysfunction on ischemic heart disease

2019 ◽  
Vol 8 (5) ◽  
pp. R76-R90 ◽  
Author(s):  
Madalena von Hafe ◽  
João Sergio Neves ◽  
Catarina Vale ◽  
Marta Borges-Canha ◽  
Adelino Leite-Moreira
Keyword(s):  
Heart Disease ◽  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Ischemic Heart Disease ◽  
Left Ventricular ◽  
Ischemic Heart ◽  
Hormone Levels ◽  
Thyroid Axis ◽  
Thyroid Hormone Levels ◽  
The Impact

Thyroid hormones have a central role in cardiovascular homeostasis. In myocardium, these hormones stimulate both diastolic myocardial relaxation and systolic myocardial contraction, have a pro-angiogenic effect and an important role in extracellular matrix maintenance. Thyroid hormones modulate cardiac mitochondrial function. Dysfunction of thyroid axis impairs myocardial bioenergetic status. Both overt and subclinical hypothyroidism are associated with a higher incidence of coronary events and an increased risk of heart failure progression. Endothelial function is also impaired in hypothyroid state, with decreased nitric oxide-mediated vascular relaxation. In heart disease, particularly in ischemic heart disease, abnormalities in thyroid hormone levels are common and are an important factor to be considered. In fact, low thyroid hormone levels should be interpreted as a cardiovascular risk factor. Regarding ischemic heart disease, during the late post-myocardial infarction period, thyroid hormones modulate left ventricular structure, function and geometry. Dysfunction of thyroid axis might even be more prevalent in the referred condition since there is an upregulation of type 3 deiodinase in myocardium, producing a state of local cardiac hypothyroidism. In this focused review, we summarize the central pathophysiological and clinical links between altered thyroid function and ischemic heart disease. Finally, we highlight the potential benefits of thyroid hormone supplementation as a therapeutic target in ischemic heart disease.

scholarly journals Acute Changes in Thyroid Hormone Levels among Thai Pesticide Sprayers

Toxics ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 16
Author(s):  
Pornpimol Kongtip ◽  
Noppanun Nankongnab ◽  
Ritthirong Pundee ◽  
Nichcha Kallayanatham ◽  
Sumate Pengpumkiat ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Urine Samples ◽  
Blood Collection ◽  
Free Triiodothyronine ◽  
Blood Samples ◽  
Hormone Levels ◽  
Pesticide Exposures ◽  
Thyroid Hormone Levels ◽  
Acute Changes

The objective of this study was to investigate the relationship of acute pesticide exposures and acute changes in thyroid hormones among Thai farmers. We recruited 78 farmers, who were scheduled to spray insecticides (chlorpyrifos and/or cypermethrin) or herbicides (paraquat and/or glyphosate). On the day before spraying, farmers collected their first morning void urine and went for blood collection. On the spray day, urine samples were collected at end of the spraying event and they were interviewed with questionnaires. The next morning, the first morning void urine and blood samples were collected. Blood samples were analyzed for thyroid hormones. Urine samples were analyzed for the metabolites of the pesticide sprayed. The results showed that the thyroid hormones, free triiodothyronine (FT3) and total triiodothyronine (T3) were significantly reduced as urinary chlorpyrifos metabolite increased the day after spraying. Total thyroxine (T4) significantly increased as cypermethrin metabolites increased the day after spraying. T4 significantly increased as urinary glyphosate levels increased; however, FT3 and T3 decreased significantly as urinary paraquat levels increased the day after spraying. These findings suggest that acute exposures to the pesticides chlorpyrifos, cypermethrin, paraquat and glyphosate can produce acute effects on the hypothalamic–pituitary–thyroid (HPT) axis, acutely altering thyroid hormone levels.

Age Moderates the Impact of TRAbs on Thyroid Hormones and Hepatic Function in Patients with Graves’ Disease

2021 ◽  
Vol 53 (07) ◽  
pp. 453-460
Author(s):  
Kai Guo ◽  
Hongwei Ling ◽  
Xiaoyan Zhou ◽  
Changjiang Ying
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Hepatic Function ◽  
Graves Disease ◽  
Newly Diagnosed ◽  
Younger Patients ◽  
Hormone Levels ◽  
Thyroid Hormone Levels ◽  
Antibody Levels ◽  
The Impact

AbstractThyrotropin receptor antibodies (TRAbs) play a significant role in the course of hepatic dysfunction (HDF) in patients with Graves’ disease (GD). However, few studies have considered the factors that influence the relationships among TRAbs, thyroid hormone levels, and hepatic function in subjects with newly diagnosed GD. Here we investigated the associations of TRAbs with thyroid hormones and hepatic function and assessed potential factors that can influence these associations among patients with GD. A total of 368 patients newly diagnosed with GD were collected in this cross-sectional study. Patients who had received antithyroid drugs, radioactive iodine, or surgery were excluded. Levels of TRAbs and thyroid hormones and hepatic function were recorded. Linear and binary logistic regression analysis models were applied to investigate associations among these variables after adjusting for confounding characteristics. There was a significant difference in TRAbs indices between the HDF and normal hepatic function groups (p <0.05). After adjusting for confounders, the relationship between TRAbs and thyroid hormones was nonlinear, showing a curve with an initial positive slope and a subsequent flattening (p <0.05). Higher TRAbs were associated with HDF [odds ratio (OR) 1.036, 95% confidence interval (CI) 1.018–1.053 per 1-IU/l increase]. These associations were modified by age, but not by gender, smoking status, Graves’ orbitopathy, thyroid-peroxidase antibody levels, or thyroglobulin antibody levels. In younger patients, increasing TRAbs were correlated with higher thyroid hormones and HDF (OR 1.034, 95% CI 1.017–1.052) per1-IU/l increase). In older patients, TRAbs were not correlated with thyroid hormones or HDF (OR 1.024, 95% CI 0.993–1.056) per 1-IU/l increase. Age can affect the impact of TRAbs on thyroid hormone levels and hepatic function in GD. TRAb measurement can have good predictive value in younger patients.

scholarly journals Clinical Associations of Thyroid Hormone Levels with the Risk of Atherosclerosis in Euthyroid Type 2 Diabetic Patients in Central China

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Limin Wang ◽  
Tingting Chen ◽  
Jiawei Yu ◽  
Huijuan Yuan ◽  
Xinru Deng ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Smoking Status ◽  
Central China ◽  
Diabetic Patients ◽  
Free Triiodothyronine ◽  
Type 2 Diabetic Patients ◽  
Hormone Levels ◽  
Thyroid Hormone Levels

Background. Thyroid function is associated with the etiology and pathogenesis of type 2 diabetes (T2D) and potentially contributes to the development of the complications of T2D. The association of thyroid hormones with atherosclerosis in euthyroid T2D patients is not clear. Purpose. To investigate the association of thyroid hormone levels with the risk of developing atherosclerosis in euthyroid T2D patients in Central China. Methods. This cross-sectional study recruited 910 euthyroid T2D patients from Henan Provincial People’s Hospital, China. Association among hemoglobin A1c (HbA1c), thyroid hormones, and the prevalence of atherosclerosis was assessed by multivariable Cox models after adjusting for covariates including age, BMI, duration of T2D, smoking status, SBP, TC, family history of T2D, and medications on hyperlipidemia. Results. Among all 910 subjects, 373 were diagnosed with atherosclerosis. There were 523 females and 387 males included in this study. The mean age was 51.9 years. The average BMI was 25.3 kg/m2. Low-normal serum-free triiodothyronine (FT3) levels (3.50–4.17 pmol/L) were associated with a high prevalence of atherosclerosis. Comparing with low-normal FT3, the prevalence ratio in patients with mid- (4.17–4.83 pmol/L) and high-normal FT3 level (4.83–6.50 pmol/L) is 0.74 (95% CI 0.56 to 0.97, p=0.029) and 0.63 (95% CI 0.46 to 0.87, p=0.005) after adjusting for covariates. High level of free thyroxine (FT4) also had decreased risk for atherosclerosis. Thyroid-stimulating hormone (TSH) and FT3 to FT4 ratio did not show significant association with the development of atherosclerosis. Conclusion. T2D patients with low but clinically normal FT3 level are more likely to develop macrovascular complications comparing with those with mid- and high-normal FT3 level.

scholarly journals Thyroid Hormones in Conventional and Organic Farmers in Thailand

2019 ◽  
Vol 16 (15) ◽  
pp. 2704 ◽  
Author(s):  
Pornpimol Kongtip ◽  
Noppanun Nankongnab ◽  
Nichcha Kallayanatham ◽  
Ritthirong Pundee ◽  
Nattagorn Choochouy ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Metabolic Diseases ◽  
Endocrine System ◽  
Thyroid Stimulating Hormone ◽  
Free T4 ◽  
Hormone Levels ◽  
Organic Farmers ◽  
Thyroid Hormone Levels ◽  
2,4 Dichlorophenoxyacetic Acid

Pesticides can act as endocrine disruptors by different mechanisms including inhibition of iodine absorption, increases in thyroid hormone clearance, decreased cellular uptake of thyroid hormones, or changes in expression of thyroid hormone regulated genes. This study examined how exposure to pesticides impacts thyroid hormone levels, thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), free T3 (FT3), and free T4 (FT4) by comparing conventional (n = 195) and organic farmers (n = 222), and by evaluating which types of pesticides might be associated with changes in thyroid hormone levels. Questionnaires were used to collect information about farmer characteristics, self-reported stress, agricultural activities, and history of pesticide use. Conventional farmers were asked to report the type and quantity of pesticides used each day. The TSH, FT3, T3, and T4 levels of conventional farmers were 1.6, 1.2, 1.3, and 1.1 times higher than those of organic farmers, respectively, after adjusting for covariates. Several specific herbicides had a significant relationship between the amount applied and an increase in thyroid hormone levels, after covariate adjustment. They included: paraquat (TSH, FT3 and T3); acetochlor (FT4); atrazine (TSH, FT3 and T3); glyphosate (T4); diuron (TSH) and the “other” herbicides including alachlor, propanil, and butachlor (FT4 and T3). The most commonly used herbicide among conventional farmers was glyphosate, followed by paraquat, 2,4-dichlorophenoxyacetic acid (2,4-D). These findings suggest that exposure to pesticides could impact the development of metabolic diseases and other health outcomes by altering the endocrine system (the thyroid hormone levels) through the hypothalamic–pituitary–thyroid (HPT) axis. This work is a part of a longitudinal study which will evaluate the sub-chronic effects of repeated exposure to different types of pesticides on thyroid hormone levels.

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