Total Triiodothyronine Concentrations Research Articles

Effects of Levothyroxine and Liothyronine on Cirrhotic Cardiomyopathy in Rats

In liver cirrhosis, there is low T3 syndrome associated with a decrease in total triiodothyronine (T3) and free T3 concentrations and cirrhotic cardiomyopathy (CCM) with chronotropic incompetence. Thus, we aimed to investigate the effects of eliminating T3 and thyroxine (T4) deficiencies on cardiac chronotropic dysfunction. Bile duct ligation (BDL) was used to induce cirrhosis in male Wistar rats. The chronotropic responses were studied through the Power Lab system in sham/saline, sham/T3T4, BDL/saline, and BDL/T3T4 groups. The serum T3 and T4, and T3 resin uptake (T3RU) levels were assessed. The atrial T3 receptor expression was investigated through a real-time polymerase chain reaction (Real-time PCR). The chronotropic responses were decreased in the BDL/saline group and raised in the BDL/T3T4 group. The serum T3 levels decreased in the BDL/saline group compared to sham group, but increased in the BDL/T3T4 group compared to the BDL/saline group. The serum T4 level increased in the BDL/saline and decreased in the BDL/T3T4 group. The serum T3RU level decreased in the BDL/saline and increased in the BDL/T3T4 group. The T3 receptor expression in atria increased in the BDL/saline group, nonetheless, it did not change in the BDL/T3T4 group compared to the sham/saline and the BDL/saline groups. T3T4 treatment did not increase the chronotropic response in the control group but the treatment improved the chronotropic hyporesponsiveness, and serum T4 and T3 RU abnormalities in cirrhosis, however, it is not related to the atrial T3 receptor expression.

Hormonal, liver, and renal function associated with electronic waste (e-waste) exposure in Dhaka, Bangladesh

Electronic waste (e-waste) contains numerous metals and organic pollutants that have detrimental impacts on human health. We studied 199 e-waste recycling workers and 104 non-exposed workers; analyzed blood, urine, and hair samples to measure heavy metals, hormonal, liver, and renal function. We used quantile regression models to evaluate the impact of Pb, Cd, and Hg on hormonal, liver and renal function, and the role of DNA oxidative damage in mediating the relationship between exposures and outcomes. Exposed workers had higher blood lead (Pb) (median 11.89 vs 3.63 µg/dL), similar blood cadmium (Cd) (1.04 vs 0.99 µg/L) and lower total mercury (Hg) in hair (0.38 vs 0.57 ppm) than non-exposed group. Exposed workers also had elevated median concentrations of total triiodothyronine (TT3), aspartate aminotransferase (AST), alanine aminotransferase (ALT), urinary albumin, albumin creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR) were significantly higher than non-exposed group (p≤0.05). Sex hormones including luteinizing hormone, follicle stimulating hormone, estrogen, progesterone and testosterone concentrations were not significantly different between exposed and non-exposed (all p≥0.05). The median concentration of ALT was 4.00 (95% CI: 0.23, 7.77), urinary albumin was 0.09 (95% CI: 0.06, 0.12) and ACR was 1.31 (95% CI: 0.57, 2.05) units higher in the exposed group compared to non-exposed group. Pb was associated with a 3.67 unit increase in the ALP (95% CI: 1.53, 5.80), 0.01 unit increase in urinary albumin (95% CI: 0.002, 0.01), and 0.07 unit increase in ACR (95% CI: 0.01, 0.13). However, no hormonal, renal, and hepatic parameters were associated with Cd or Hg. Oxidative DNA damage did not mediate exposure-outcome relationships (p≥0.05). Our data indicate e-waste exposure impairs liver and renal functions secondary to elevated Pb levels. Continuous monitoring, longitudinal studies to evaluate the dose-response relationship and effective control measure are required to protect workers from e-waste exposure.

Total thyroxine, triiodothyronine, and thyrotropin concentrations during acute nonthyroidal illness and recovery in dogs.

Acute illness can result in changes in serum total thyroxine (tT4), total triiodothyronine (tT3), and thyrotropin (TSH) concentrations in euthyroid dogs defined as nonthyroidal illness syndrome, but longitudinal evaluation of these hormones during the recovery phase is lacking. To longitudinally evaluate serum tT4, tT3, and TSH concentrations during the acute phase and recovery from acute illness in dogs. Nineteen euthyroid client-owned dogs hospitalized for acute illness at a veterinary teaching hospital. Prospective longitudinal study. Serum tT4, tT3, and TSH concentrations were measured at the admission (T0), at last day of hospitalization (T1), and during the recovery phase at 3, 7, 14, and 21 days after the discharge (T2, T3, T4, and T5), respectively. tT4 and tT3 were below the reference interval (RI) at T0 in 3 (16%) and 18 (95%) dogs, respectively; tT4 normalized in all dogs early in the recovery phase, while low tT3 persisted at the end of the study in 16 (83%) dogs. Median TSH concentrations were increased at T5 compared with T1 (0.19 ng/mL [range 0.03-0.65] vs 0.11 ng/mL [range (0.05-0.26)], mean difference = 0.09 ng/mL; P = .03). Five (26%) dogs had TSH above the RI at least at 1 time point during the recovery phase. None of the dogs had concurrent low tT4 and high TSH during the study. In euthyroid dogs acute illness can interfere with evaluation of thyroid function up to 21 days during the recovery phase. Thyroid testing should be avoided or postponed in these dogs.

Calculation of reference intervals for indicators of thyroid hormones and cortisol in horses

The article discusses the results of calculating reference intervals for thyroid hor mones and cortisol in adult horses. The study included the results of a laboratory study of the concentrations of total triiodothyronine, total and free thyroxine and cortisol from 50 horses aged 3 to 29 years, including 17 mares, 13 stallions and 20 geldings. All animals underwent an extensive biochemical blood test, the results of which revealed no pathological changes.To calculate the normative limits of fluctuations for each hormone, calculations were carried out using the Tukey method, which is used to determine the reference limits in the case of a small number of variants in the group and the absence of a normal distribution. Microsoft Excel was used for calculations. The conducted studies made it possible to clarify the reference intervals for thyroid hormones and cortisol in horses, which were: total triiodothyronine (T3) - 1.13-4.04 nmol/l, total thyroxine (T4) - 20.97-57.42 nmol/l, free thyroxine (fT4) 7.38-23.07 pmol/l, cortisol – 39.42-227.02 nmol/l. The results obtained can be recommended for use not only for the clinical and biochemical laboratory of St. Petersburg State University of Medicine, but also for all veterinary laboratories using diagnostic test systems for enzyme immunoassay of Vital Development Corporation.

Relationship between thyroid function and sex hormones in female German shepherd dogs.

Several variables influence the serum concentration of thyroid hormones in dogs, including breed, age, drugs, and concurrent diseases. However, data regarding the interaction between thyroid function and the estrous stage of female dogs are limited. Estrous stage may influence thyroid function in German Shepherd dogs. Longitudinal, observational, non-randomized cohort study. The dogs were monitored during the complete estrous cycle, and different stages were determined by vaginal cytology. Two blood samples were collected at the beginning and end of each stage to analyze the following: total thyroxine (TT4), free thyroxine (fT4), total triiodothyronine (TT3), free triiodothyronine (fT3), canine thyrotropin (cTSH), progesterone, 17-β-estradiol, triglycerides, and cholesterol concentrations. Hematological and biochemical evaluations were performed at the beginning and end of the study period. Seventeen German Shepherds were included, of which 7 were bred during the study period. One dog was excluded for estrus interruption and another for suspected hypothyroidism. Serum concentrations of T4, fT4, and fT3 were negatively correlated with age. Total thyroxine demonstrated significant changes in serum concentrations between estrous stages, with higher concentrations in estrus and diestrus. Total thyroxine concentrations were positively correlated with progesterone concentrations and negatively correlated with 17-β-estradiol concentrations. Free thyroxine did not show significant variations but was positively correlated with progesterone concentrations. Canine TSH concentrations were positively correlated with 17-β-estradiol concentrations. No significant differences in thyroid hormones and cTSH concentrations were observed between diestrus during pregnancy and pseudopregnancy. Different stages of estrus can influence the measurement of TT4 in female dogs.

Mediation by Thyroid Hormone in the Relationships Between Gestational Exposure to Methylmercury and Birth Size

Our previous studies have linked gestational methylmercury exposure, originating from seafood, to changes in maternal thyroid hormones and infant birth size in a Swedish birth cohort. Herein we aimed to determine associations between maternal thyroid hormones and infant birth size and elucidate if maternal hormones could mediate the relationship between methylmercury and lower birth size. In 515 women, without known thyroid disease, we assessed metal exposure by erythrocyte mercury concentrations (mainly methylmercury, reflecting exposure over the past months) in early third trimester measured with inductively coupled plasma-mass spectrometry. Plasma concentrations of total and free thyroxine (tT4 and fT4) and triiodothyronine (tT3 and fT3), and thyroid-stimulating hormone (TSH) were measured at an accredited clinical laboratory. In multivariable-adjusted linear regression models, maternal tT3 (per 1 nmol/L increase) was positively associated with birth weight (B: 125 g; 95% CI 36, 214) and length (B: 0.59 cm; 95% CI 0.21, 0.97). Maternal fT4 was inversely associated with birth weight (B: − 33 g; 95% CI − 57, − 9.5), driven by obese women (n = 76). Causal mediation analyses suggested that a doubling of erythrocyte mercury (> 1 µg/kg; n = 374) was associated with a mean tT3-mediated decrease in birth weight of 11 g (95% CI − 25, − 1.6) and in birth length of 0.1 cm (95% CI − 0.12, − 0.01), both equivalent to about 12% of the total effect. To conclude, tT3 was positively associated with infant birth size. Reduced tT3 levels appeared to mediate a minor part of the inverse association between methylmercury exposure and birth size.

Intrauterine Food Restriction is Associated with Obesity in Young Rats

The purpose of this study was to examine the effects of malnutrition during the first 2 wk of intrauterine life on the regulation of energy metabolism and the activity of brown adipose tissue in rats at 53 d of age. Intrauterine malnutrition led to an imbalance in the control of energy metabolism that was influenced by gender. In males, the intrauterine malnutrition resulted in impairment of normal weight gain and fat deposition during 1 to 53 d of age, in association with low plasma total triiodothyronine concentration, in spite of normal food intake. In contrast, the intrauterine malnutrition in females led to a marked fat accumulation by 53 d of age with normal food intake, and decreased brown adipose tissue weight, protein content and cytochrome c oxidase activity, indicating a lower sympathetic activity. These data indicate that nutrient availability during the first 2 wk of intrauterine life determines the control of energy utilization during early post-weaning period.

Comparative Study of Some Hematological, Biochemical and Thyroid Biomarkers on Males and Females (Gallinula Chloropus) Water Birds

The current study was objective in clarifying some of the physiological and hormonal characteristics on male and female of migratory water birds Gallinula Chloropus, that bought from Basrah market during the winter season. This study conducted on 30 healthy birds was divided into fifteen males and fifteen females and suggest that the male Gallinula Chloropus has higher levels of red blood cells count(RBC), hemoglobin( Hb) and Packed cell volume (PCV) than the females, while the total protein, albumin, globulin, calcium, phosphorus, and triiodothyronine (T3) concentrations recorded high significantly in the female than the males. In addition, there is no difference in the levels of Thyroid stimulation hormone (TSH) and blood glucose.

Thyroid-Related Hormone Levels in Clinical Patients With Moderately Severe-to-Profound Sudden Sensorineural Hearing Loss: A Prospective Study.

Objectives: Sudden sensorineural hearing loss (SSNHL) is a common otological emergency, causing a measure of hearing loss and affecting the quality of life. This study aims to investigate the association of thyroid-related hormone levels with moderately severe-to-profound SSNHL.Methods: The study included 70 patients with moderately severe-to-profound SSNHL and 100 age- and sex-matched healthy controls. Peripheral venous blood samples were taken from the participants, and their thyroid-related hormone levels were measured at admission and 1 week after treatment.Results: In moderately severe-to-profound SSNaHL patients, the concentrations of total triiodothyronine (TT3), total thyroxine (TT4), free triiodothyronine (FT3), and thyroid-stimulating hormone (TSH) (all P < 0.05) were significantly lower than in the control group. The TT3, TT4, FT3, and TSH levels were significantly higher in the effective group than in the ineffective group (all P < 0.05). Linear correlation analysis revealed that TSH level (R = 0.707, P < 0.05) elevation after treatment successfully predicted a favorable outcome of hearing recovery. Logistic regression analyses suggested low FT3 and TSH levels to be independent occurrence predictors, while the increase of TSH level may be an independent favorable outcome predictor.Conclusions: The results suggest that low FT3 and TSH levels are risk factors for moderately severe-to-profound SSNHL. By discovering the positive association between TSH elevation and hearing recovery, along with the potential novel predictors of FT3 and TSH, our study may contribute valuable insights to the research and treatment of moderately severe-to-profound SSNHL.

Адаптационный потенциал и эндокринный статус работников целлюлозно- бумажного комбината г. Архангельска

Introduction. Maintaining good health and working capacity of the population is one of the main tasks of the healthcare system. Living under adverse climatic conditions of the North and being exposed to dangerous production factors of the pulp and paper industry, strongly represented in the Arkhangelsk Region, can significantly reduce the adaptive capacity of the body. Major role in providing an adequate response to the action of irritators and initiating the adaptation process is played by the neuroendocrine, cardiovascular, and circulatory systems, which reflect qualitative and quantitative changes in the body while being reliable markers of homeostasis. The aim was to study the adaptive potential of workers showing the level of functioning of the circulatory system and to evaluate their endocrine profile depending on the revealed functional capabilities of the body. Materials and methods. The study involved 50 men aged 22–60 years working in the production departments of Solombala Pulp and Paper Mill (Arkhangelsk) with a body mass index of 19–25 and without earlier history of endocrine pathology. Serum levels of thyroxine-binding globulin and oestradiol were determined by means of radioimmunoassay, while serum concentrations of total cortisol, thyrotropin, thyroxine, triiodothyronine, progesterone, testosterone, insulin, C-peptide, and somatotropin were determined by enzyme-linked immunosorbent assay. Results. The research demonstrated that in 2/3 of the examined employees of the pulp and paper mill the adaptation mechanisms were under strain, while the condition of two subjects corresponded to the physiological norm, which is characterized by good and satisfactory adaptation. Workers with decreased adaptive capabilities to the point of unsatisfactory adaptation showed increased levels of cortisol, thyroxine-binding globulin, oestradiol, C-peptide, and insulin against the background of a decrease in testosterone, progesterone, and the testosterone/oestradiol ratio. The authors recommend conducting periodic medical examinations of pulp and paper workers, including endocrine profile assessment, and monitoring changes that occur over time.

Gestational Hormone Concentrations Are Associated With Timing of Delivery in a Fetal Sex-Dependent Manner.

BackgroundEarly delivery remains a significant public health problem that has long-lasting impacts on mother and child. Understanding biological mechanisms underlying timing of labor, including endocrine disruption, can inform prevention efforts.MethodsGestational hormones were measured among 976 women in PROTECT, a longitudinal birth cohort in Puerto Rico. We evaluated associations between hormone concentrations at 18 and 26 weeks gestation and gestational age at birth, while assessing effect modification by fetal sex. Exploratory analyses assessed binary outcomes of overall preterm birth (PTB, <37 weeks gestation) and the spontaneous PTB subtype, defined as preterm premature rupture of membranes, spontaneous preterm labor, or both. Multivariable logistic and linear regressions were fit using visit-specific hormone concentrations, and fetal sex-specific effects were estimated using interaction terms. Main outcome models were adjusted for maternal age, education, marital status, alcohol consumption, environmental tobacco smoke exposure, and pre-pregnancy body mass index (BMI). Exploratory models adjusted for maternal age and education.ResultsWe observed reduced gestational age at birth with higher circulating CRH (β: -2.73 days, 95% CI: -4.97, -0.42), progesterone (β: -4.90 days, 95% CI: -7.07, -2.73), and fT4 concentrations (β: -2.73 days, 95% CI: -4.76, -0.70) at 18 weeks specifically among male fetuses. Greater odds of overall and spontaneous PTB were observed among males with higher CRH, estriol, progesterone, total triiodothyronine (T3), and free thyroxine (fT4) concentrations. Greater odds of PTB among females was observed with higher testosterone concentrations.ConclusionsVarious associations between hormones and timing of delivery were modified by fetal sex and timing of hormone measurement. Future studies are needed to understand differential mechanisms involved with timing of labor between fetal sexes.

Clinicopathological and Reproductive Studies on The Use of Ivermectin in Ewes

This study aimed to investigate the effect of Ivermectin (IVM) on the reproductive hormones and hemato-biochemical parameters of twenty apparently healthy ewes weighing 30-40 kg and 2-3 years old. Ewes were randomly divided into two groups (ten for each). The first group was left without treatment (control group), and the second was treated with the recommended therapeutic dose of IVM (0.2 mg/kg, S/C) one day after parturition (treated group). The study continued for three months. Blood samples were collected from the two groups at the 1st, 30th, 60th, and 90th days after IVM treatment. The current study revealed that IVM injection delayed estrous for up to 3 months (absence of estrous signs and no ovarian structures were observed by sonar examination). There was a significant decrease in hemoglobin concentration (Hb), red blood cells (RBCs) count, andpacked cell volume (PCV), with a significant increase in total leukocytic count (TLC) at 30th and 60th days post-treatment (p.t.). In addition to a significant decreased at (P<0.05) in the activity of glutathione peroxidase (GSH) and concentrations of total antioxidants (TAC), copper (Cu), phosphorus (P), estradiol, triiodothyronine(T3), and tetraiodothyronine (T4) for up to 3 months. In contrast, a significant increase in concentrations of calcium (Ca), progesterone and cortisol, and activity of malondialdehyde (MDA), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) enzymes were recorded at 30th and 60th days p.t. It has been concluded that IVM delayed estrous in ewes for three months via disturbing the female reproductive hormones and the hemato-biochemical parameters. Therefore, it is recommended that IVM not be injected at least three months before the reproductive season.

Per- and Polyfluoroalkyl Substances Are Positively Associated with Thyroid Hormones in an Arctic Seabird.

Per- and polyfluoroalkyl substances (PFAS) are associated with several disrupted physiological and endocrine parameters. Regarding endocrine mechanisms, laboratory studies suggest that PFAS could disrupt the thyroid hormone system and alter circulating thyroid hormone concentrations. Thyroid hormones play a ubiquitous role-controlling thermoregulation, metabolism, and reproduction. However, evidence for disruption of thyroid hormones by PFAS remains scarce in wildlife. The present study investigated the associations between concentrations of PFAS, thyroid hormones, and body condition in an arctic seabird, the black-legged kittiwake (Rissa tridactyla). We collected blood from kittiwakes sampled in Svalbard, Norway (2013 and 2014). Plasma samples were analyzed for total thyroxine (TT4) and total triiodothyronine (TT3) concentrations; detected PFAS included branched and linear (lin) C8 perfluoroalkyl sulfonates (i.e., perfluoroctane sulfonate [PFOS]) and C9 -C14 perfluoroalkyl carboxylates (PFCAs). The dominant PFAS in the kittiwakes were linPFOS and C11 - and C13 -PFCAs. Generally, male kittiwakes had higher concentrations of PFAS than females. We observed positive correlations between linPFOS, C10 -PFCA, and TT4 in males, whereas in females C12-14 -PFCAs were positively correlated to TT3. Interestingly, we observed contrasted correlations between PFAS and body condition; the direction of the relationship was sex-dependent. Although these results show relationships between PFAS and circulating thyroid hormone concentrations in kittiwakes, the study design does not allow for concluding on causal relationships related to effects of PFAS on the thyroid hormone system. Future experimental research is required to quantify this impact of PFAS on the biology of kittiwakes. The apparently different associations among PFAS and body condition for males and females are puzzling, and more research is required. Environ Toxicol Chem 2021;40:820-831. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Iodine Modifies the Susceptibility of Thyroid to Fluoride Exposure in School-age Children: a Cross-sectional Study in Yellow River Basin, Henan, China.

Excessive fluoride exposure has detrimental effects on the thyroid gland, which may be modified by iodine. However, the role of iodine in it remains unclear. This study aims to evaluate the role of iodine in thyroid abnormalities caused by fluoride exposure in school-age children. A total of 446 children aged 7-12 years were recruited from Tongxu County, Henan province, in 2017 (ZZUIRB 2017-018). We obtained demographic information through questionnaire surveys. The concentrations of urinary fluoride (UF) and urinary iodine (UI) were determined by the ion-selective electrode method and the catalytic spectrophotometric method, respectively. The radiation immunoassay was used to determine the serum concentrations of total triiodothyronine (TT3), total thyroxine (TT4), and thyroid-stimulating hormone (TSH). The B-mode ultrasound was performed to assess thyroid volumes (Tvols). The associations between fluoride exposure and thyroid-related indicators were tested by linear regression models. We found that Tvols increased by 0.22 (95% CI: 0.14, 0.31) cm3 with each standard deviation increment of UF. Moreover, Tvols in boys were more susceptible to fluoride exposure than those in girls, and the Tvols of children with high urinary iodine are less susceptible to fluoride exposure (P for interaction < 0.05). We also observed that TT3 levels were negatively related to UF concentrations at moderate urinary iodine levels (≤ 300 μg/l). Fluoride exposure can elevate the Tvols of school-age children, especially in boys, and high levels of iodine may alleviate this effect to some extent.

Evaluation of serum analytes in pregnant and non-pregnant dairy cows as indicators of pregnancy

This study was conducted to reveal the dynamics of haematological indicators in pregnant and non-pregnant dairy cows. Sixty multiparous healthy dairy cows were divided into four groups based on the length of time they had been pregnant, namely first, second and third trimesters, and non-pregnant (n=15 each). Blood was collected from each animal, and serum was harvested and stored at -20 °C for biochemical profiling. Concentrations of serum total oxidants (TOC), ceruloplasmin oxidase (CpO) and triiodothyronine (T3) were higher (P &lt;0.05) during the third trimester compared with non-pregnant cows. Serum arylesterase (Ary) concentration was lower (P &lt;0.05) during the second and the third trimesters compared with the non-pregnant cows. The concentration of serum total homocysteine (tHcy) was higher (P &lt;0.05) the third trimester compared with the first and the second trimesters. The concentrations of serum total antioxidants (TAC), paraoxonase 1 (PON1), thyroxine (T4), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were not different in the pregnant and the non-pregnant cows. Thus, TOC, Ary, CpO, tHcy and T3 could be taken as biological markers to assess the progression of pregnancy and to develop management tools to improve health status during late gestation in dairy cows&#x0D; Keywords: ceruloplasmin, hepatic enzymes, late gestation, triiodothyronine

Euthyroid Sick Syndrome and Changes in Thyroid Hormones in Dogs with Hemoparasitosis

Background: Hemoparasitoses are extremely important in the clinical routine because they affect a large number of dogs. In spite of the abundance of studies on this topic, hormonal alterations caused by infection with these agents are still poorly known. Therefore, the goal of this work was to assess the serum levels of thyroid hormones of dogs infected with Ehrlichia canis (E. canis) alone, and dogs infected with E. canis and Babesia canis vogeli (B. vogeli) and/or Anaplasma platys (A. platys) before and after treatment with doxycycline chlorohydrate. This study also aimed at checking for presence of euthyroid sick syndrome (ESS) in these animals.Materials, Methods &amp; Results: The concentrations of the thyroid hormones total triiodothyronine (TT3), total tetraiodothyronine (TT4), free tetraiodothyronine (FT4), and canine thyroid-stimulating hormone (cTSH) were assessed by chemiluminescence in 12 dogs. Nested polymerase chain reaction (nPCR) was used to confirm diagnoses. The dogs were divided into 2 groups: G1, which comprised animals infected by E. canis alone, and G2, which included animals simultaneously infected by E. canis and B. vogeli and/or A. platys. The serum concentrations of the thyroid hormones were measured at two time points: before (D1) and after (D2) the 28-day treatment with generic doxycycline chlorohydrate (DC) at a dose of 10 mg/kg SID. On D2, another nPCR was carried out to check the efficacy of the treatment. On D2, in both groups, all dogs became negative for E. canis; however, 8 animals remained infected or were reinfected by other hemoparasites. On D1, 4 dogs in G1 exhibited low TT3 in conjunction with low TT4; one of the dogs had increased TT3 alone, and another dog had an increased TT3 accompanied by decreased TT4. In G2, on D1, one dog exhibited high TT3 accompanied by a decreased concentration of TT4; 2 dogs had decreased TT4; 2 dogs had increased TT3; and one dog had both TT3 and TT4 decreased. On D2, with only one exception, the animals in G1 that became negative for all hemoparasites under study exhibited normal serum levels of TT3 and TT4. Three dogs in G1, which were reinfected on D2, sustained decreased TT4 serum concentrations. Whereas, in G1 on D2, only one dog remained with a reduced serum TT4 concentration.Discussion: DC was effective at eliminating infection by E. canis in all dogs on D2. Even though this drug was unable to prevent reinfection of the animals by other hemoparasites, and in spite of divergent results on its efficacy at eliminating babesiosis and anaplasmosis, a clinical improvement was observed in all patients. A decrease in the serum concentrations of thyroid hormones (ESS) may occur in dogs with severe non-thyroid related diseases. Different authors have demonstrated the presence of ESS in dogs with hemoparasitoses; however, this is the first study to provide evidence on the existence of this syndrome in dogs with hemoparasitoses in Brazil, including dogs simultaneously infected by E. canis and B. vogeli and/or A. platys.We observed a reduction in TT3 and/or TT4 in dogs infected by E. canis, B. vogeli, and A. platys. We believe these results may help assessment of prognosis and patient follow-up, as TT4 concentrations returned to normal levels in all dogs that became negative for all hemoparasites after treatment; and only one dog in G1 sustained increased TT3, albeit lower than observed on D1. In animals of G1 that were reinfected after treatment started, TT3 returned to normal, even though TT4 levels remained decreased. In sum, all dogs in G1 and G2 exhibited TT3 and/or TT4 concentrations outside of the reference value ranges on D1, which indicates that alterations in the levels of thyroid hormones were due to infection by the hemoparasites. The animals infected by E. canis alone or simultaneously infected by B. vogeli and/or A. platys exhibited ESS.

Thyroid Hormone Changes in Early Pregnancy Along With the COVID-19 Pandemic.

PurposeCOVID-19 (Coronavirus Disease 2019) was first reported in December 2019 and quickly swept across China and around the world. Levels of anxiety and depression were increased among pregnant women during this infectious pandemic. Thyroid function is altered during stressful experiences, and any abnormality during early pregnancy may significantly affect fetal development and pregnancy outcomes. This study aimed to determine whether the COVID-19 pandemic induces thyroid hormone changes in early pregnant women.MethodsThis study comprised two groups of pregnant women in Shanghai in their first trimester – those pregnant women before the COVID-19 outbreak from January 20, 2019, to March 31, 2019 (Group 1) and those pregnant during the COVID-19 outbreak from January 20, 2020, to March 31, 2020 (Group 2). All women were included if they had early pregnancy thyrotropin (TSH), free triiodothyronine (FT3), free thyroxine (FT4), total triiodothyronine (TT3), and total thyroxine (TT4) concentrations, thyroid peroxidase (TPO) antibody or thyroglobulin antibody (TgAb) available and did not have a history of thyroid diseases or received thyroid treatment before or during pregnancy. We used propensity score matching to form a cohort in which patients had similar baseline characteristics.ResultsAmong 3338 eligible pregnant women, 727 women in Group 1 and 727 in Group 2 had similar propensity scores and were included in the analyses. Pregnant women in Group 2 had significantly higher FT3 (5.7 vs. 5.2 pmol/L, P<0.001) and lower FT4 (12.8 vs. 13.2 pmol/L, P<0.001) concentrations compared with those in Group 1. Pregnant women in Group 2 were more likely to develop isolated hypothyroxinemia (11.6% vs. 6.9%, OR, 1.75 [95% CI, 1.20–2.53], P=0.003) than those in Group 1 but had a significantly lower risk of TgAb positivity (12.0% vs. 19.0%, OR, 0.58 [95% CI, 0.43–0.78], P<0.001).ConclusionPregnant women in their first trimester in Shanghai during the COVID-19 outbreak were at an increased risk of having higher FT3 concentrations, lower FT4 concentrations, and isolated hypothyroxinemia. The association between thyroid hormones, pregnancy outcomes, and the COVID-19 outbreak should be explored further.

Meconium Exposure to Phthalates, Sex and Thyroid Hormones, Birth Size and Pregnancy Outcomes in 251 Mother-Infant Pairs from Shanghai.

Phthalates are hormonally active pollutants. In-utero exposure to phthalates has been reported to be associated with birth size parameters and pregnancy outcomes. However, previous reports were inconsistent. We examined the associations between meconium exposure to phthalates and the effects on birth size parameters, pregnancy outcomes and sex and thyroid hormones in 251 mother–infant pairs from a Shanghai hospital. We measured 10 metabolites of phthalates in meconium samples collected during the first 24h after delivery. Information on seven birth size parameters (birth weight, birth length, abdominal circumference, head circumference, femur length, biparietal diameter and anogenital distance) and three pregnancy outcomes (gestational diabetes, premature rupture of membrane, and premature birth) was available from the birth record. Concentrations of free testosterone, estradiol (E2), thyroid stimulating hormone, concentrations of total and free thyroxine and triiodothyronine were measured from cord blood. Multivariate linear regression and logistic regression were used to estimate associations between phthalate exposure and health outcomes. mono-iso-butylphthalate (MiBP), mono-n-butylphthalate (MnBP) and mono-2-ethyl-5-oxohexyl phthalate (MEOHP) were positively associated with birth length and femur length which seemed more obvious in female newborn; MiBP, MnBP and mono-2-ethylhexylphthalate (MEHP) were positively associated with gestational diabetes mellitus (GDM) only in mothers with male newborns; monomethyl phthalate (MMP), MiBP and MEOHP were positively associated with E2 in male newborns. This study indicates that meconium exposure to phthalates may adversely affect some fetal growth parameters and GDM with a potential gender effect.

No Longterm Severe Thyroid Dysfunction Seen In Patients With Preexisting Reduced Serum Tt3 Concentrations After A Single Large Dose Of Iodinated Contrast

After an intravenous bolus injection of 100 mL of iodinated contrast agent (370 mgI/mL), the amount of iodine atoms entering the blood is tens of thousands of times the daily dose of iodine recommended by the World Health Organization. However, the effect of iodinated contrast in patients with nonthyroidal illness, manifested as reduced serum total triiodothyronine (TT3) concentrations, is unclear. We studied the effect of iodinated contrast on thyroid function and auto-antibodies in patients with reduced TT3 after diagnosis and treatment of coronary heart disease. This was a prospective cohort study. One hundred and fifty-four stable angina pectoris patients with reduced TT3 and normal thyroid-stimulating hormone (TSH), free thyroxine (FT4), and reverse triiodothyronine (rT3) were enrolled from January, 2017, to June, 2018. All subjects had no history of thyroid dysfunction and had no recent infections, tumors, trauma, or other critical illnesses. Fourty-one patients underwent coronary angiography and 113 patients underwent coronary intervention. There were 6 patients (3.9%) with hypothyroidism and 30 patients (19.5%) developed subclinical hypothyroidism (SCHypo) on the first day after surgery. There were 6 patients (3.9%) with hypothyroidism, 6 patients (3.9%) with SCHypo, and 18 patients (11.7%) with subclinical hyperthyroidism (SCHyper) at the first month postsurgery. There were 23 patients (14.9%) with SCHyper and 6 patients (3.9%) with SCHypo at the sixth month after surgery. No patient with longterm severe thyroid dysfunction occurred during follow-up. The levels of free triiodothyronine, FT4, TT3, total thyroxine, and TSH showed statistically significant changes at 1 day, and 1, 3, and 6 months postoperative (P<.005). The level of rT3 showed no statistically significant change at 1, 3, and 6 months postoperative (P>.05). The levels of thyroglobulin antibody and thyroid peroxidase antibody decreased at 6 months postoperative (P<.001). The risk of subclinical thyroid dysfunction and transient hypothyroidism occurred with a single large dose of iodinated contrast in the diagnosis and treatment of coronary heart disease, but no longterm severe thyroid dysfunction occurred. Patients with preoperative thyroid antibody elevation were more likely to have subclinical thyroid dysfunction after surgery. FT3 = free triiodothyronine; FT4 = free thyroxine; PCI = percutaneous coronary intervention; rT3 = reverse triiodothyronine; SCHyper = subclinical hyperthyroidism; SCHypo = subclinical hypothyroidism; TGAB = thyroglobulin antibody; TPOAB = thyroid peroxidase antibody; TT3 = total triiodothyronine; TT4 = total thyroxine; TSH = thyroid-stimulating hormone; WHO = World Health Organization.

Urinary Concentrations of Phthalate Metabolite Mixtures in Relation to Serum Biomarkers of Thyroid Function and Autoimmunity among Women from a Fertility Center.

Background:Although previous epidemiological studies have explored associations of phthalate metabolites with thyroid function, no studies to date have assessed associations of mixtures with thyroid function and autoimmunity among potentially susceptible subgroups such as subfertile women.Objective:We aimed to explore associations of mixtures of urinary phthalate metabolites with serum markers of thyroid function and autoimmunity.Methods:This cross-sectional study included 558 women attending a fertility center who provided one spot urine and one blood sample at enrollment (2005–2015). We quantified urinary concentrations of eight phthalate metabolites using mass spectrometry, and biomarkers of thyroid function [thyroid-stimulating hormone (TSH), free and total thyroxine (, ) and triiodothyronine (, ), and autoimmunity [thyroid peroxidase and thyroglobulin antibodies (TPOAb and TgAb, respectively)] in serum using electrochemiluminescence assays. We applied principal component analysis (PCA) and Bayesian kernel machine regression (BKMR) to identify the main patterns of urinary phthalate metabolites. We used linear mixed models to assess the association between PCA-derived factor scores in quintiles and serum thyroid function and autoimmunity, adjusting for age, body mass index (BMI), specific gravity (SG), and, for the PCA, other factor scores.Results:We observed two factors using PCA, one representing the di(2-ethylhexyl) (DEHP) and another non-DEHP metabolites. Compared to women in the lowest quintile of the DEHP factor scores, women in the highest quintile had significantly lower serum concentrations of , , , and [absolute difference: ; 95% confidence interval (CI): , ; ; absolute difference: ; 95% CI: , ; ; absolute difference: ; 95% CI: 0.54, ; ; and absolute difference: ; 95% CI: , ; , respectively]. Using BKMR, we observed that mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) was the primary contributor to these negative associations. DEHP and non-DEHP factor scores were not associated with serum TSH, TgAb, or TPOAb.Conclusions:Mixtures of urinary DEHP metabolites were inversely associated with serum biomarkers of thyroid function but not with autoimmunity, which were within normal ranges for healthy adult women. https://doi.org/10.1289/EHP6740