Changes In Thyroid Hormones Research Articles

Thyroid Hormone Changes Related to Growth Hormone Therapy in Growth Hormone Deficient Patients.

The alterations in thyroid function during recombinant human growth hormone (rhGH) treatment have been reported by many authors since this therapy became widely available for patients with growth hormone deficiency (GHD). Decrease of thyroxine level is the most frequent observation in patients treated with rhGH. This paper presents literature data describing changes in thyroid function related to rhGH therapy and a current explanation of mechanisms involved in this phenomenon. The effect of GH on the hypothalamic-pituitary-thyroid (HPT) axis is dependent on a multilevel regulation beginning from influence on the central axis, thyroid, and extra-thyroidal deiodinases activity as well as the impact on thyroid hormone receptors on the end. Changes in central and peripheral regulation could overlap during rhGH therapy, resulting in central hypothyroidism or an isolated slight deficiency of thyroxine. The regular monitoring of thyroid function is recommended in patients treated with rhGH and the decision of levothyroxine (L-thyroxine) supplementation should be made in the clinical context, taking into account thyroid hormone levels, as well as the chance for satisfactory growth improvement.

Quetiapine-Induced Thyroid Dysfunction: A Systematic Review.

Thyroid abnormalities are documented consequences of quetiapine treatment. This may have clinical implications as changes in thyroid hormones may deteriorate a person's affective state. Yet less is known about the clinical factors and underlying mechanisms associated with thyroid hormones on quetiapine therapy. We therefore systematically reviewed the published literature of evidence of quetiapine-induced thyroid abnormalities. We searched MEDLINE, PsycINFO, Google Scholar, and EMBASE for articles in which individuals developed biochemically confirmed thyroid abnormalities (with or without clinical symptoms) while on quetiapine treatment. We included case reports, case series, observational, and experimental studies. We included 32 studies, 20 of which were observational and experimental studies. There were 10 case reports and 1 case series. All the research designs suggested an association between quetiapine and hypothyroidism. However, these findings were limited by the quality of the included studies and the general lack of either a clear temporal relationship or dose response. Quetiapine has been associated with thyroid abnormalities, mainly with hypothyroidism. Drug imputability in these abnormalities is not always clear, and the underlying pathophysiology may include immunological and nonimmunological mechanisms. Large prospective studies are required to clarify this association and to further inform the management of patients treated with quetiapine where hypothyroidism occurs.

Thyroid and pituitary-adrenal activity in patients with asthma and endemic subclinical hypothyroidism in response of respiratory tract to a cold stimulus

Introduction. In patients with uncontrolled asthma, the stress-induced production of glucocorticosteroids in response to a cold bronchoprovocation test is increased, which is associated with an increase in the level of thyroidstimulating hormone (TSH), characteristic of the syndrome of subclinical hypothyroidism (SH). The peculiarities of thyroid hormone metabolism and changes in pituitary-adrenal homeostasis that develop in asthma in a goiter-endemic region under the influence of cold stress factors on the respiratory system are poorly studied.Aim. To assess the activity of the pituitary-thyroid and pituitary-adrenal systems in response to bronchoprovocation with cold air in asthma patients with cold airway hyperresponsiveness (CAHR) and SH living in conditions of goiter endemic in the Amur Region.Materials and methods. In 34 asthma patients with CAHR, without symptoms of thyroid diseases, the level of disease control was assessed using the Asthma Control Test (ACT) questionnaire. Lung function and airway reaction to a cold stimulus (ΔFEV1IHCA) during 3-minute isocapnic hyperventilation with cold (-20ºC) air (IHCA) were measured. Methods of immunological diagnostics in the blood of patients before and after the IHCA test were used to measure the concentrations of thyroid-stimulating (TSH) and adrenocorticotropic (ACTH) hormones, common and active forms of thyroxine (T4) and triiodothyronine (T3), thyroglobulin (TG), autoantibodies to thyroperoxidase (AB-TPO), cortisol. The content of cyclic adenosine monophosphate (cAMP) was determined in leukocytes.Results. The patients were divided into two groups: group 1 included 25 patients with an initially low (<4.0) TSH level (2.39±0.18 mU/L), group 2 included 9 patients with an initially high (>4, 0) TSH level (4.80±0.46 mU/L, p<0.0001). The ACT control level in groups 1 and 2 was 16.6±1.0 and 15.3±1.5 points (p>0.05), base FEV1 was 95.8±3.3 and 81.0±5.4% (p=0.026), ΔFEV1IHCA -11.9±0.96 and -13.5±2.7 (p>0.05), respectively. In group 1, in response to IHCA, the level of free T4 increased from 14.2±0.70 to 15.2±0.71 pmol/L (p<0.05), free T3 from 3.73±0.24 to 4.15±0.21 nmol/L (p<0.05). In group 2, a lower level of free T4 was recorded, both before (12.2±1.52 pmol/L) and after IHCA (11.6±1.60 pmol/L, p=0.041). In addition, in group 2 patients, the cortisol concentration at baseline and after IHCA (516.6±31.6 and 397.4±40.4 nmol/L, p<0.05) was significantly lower than in group 1 (628.3±27.5 and 608.3±34.1 nmol/L, p=0.042; p=0.002, respectively). A close correlation was found between ΔFEV1 and the T4 level before (r=0.54; p<0.01) and after the test (r=0.41; p<0.05), with the amount of cAMP up to (r=0.58; p=0.008) and after the test (r=0.47; p=0.009), as well as the correlation between ΔМEF50 and the initial level of cortisol in the blood serum (r=0.50; p=0.002).Conclusion. In asthma patients with CAHR living in the region of cold climate and goiter endemic, the presence of SH can be considered as a prognostic sign of the development of dysadaptation of the respiratory system to cold exposure.

Age-related changes in thyroid hormones, some serum oxidative biomarkers and trace elements and their relationships in healthy Saanen goat kids during the first three month of age.

Early-life diseases in dairy animals are main causes of economic loss in livestock production. Oxidative stress (OS) and thyroid hormones are important inter-related components in the normal physiology of this critical period of life. However, limited information regarding their physiology in goat kids is available. This study was conducted to investigate the age-related changes of thyroid hormones, some serum oxidative biomarkers and trace elements in healthy Saanen goat kids. Nineteen newborn healthy Saanen goat kids (14 females and five males) were studied longitudinally from birth until three months of age. Blood sampling was performed 24-48h after birth and was repeated on 10±2, 28±2, 56±2 and 84±2days of age. The serum levels of thyroid hormones, malondialdehyde (MDA), reduced glutathione (GSH), total antioxidant capacity (TAC), selenium (Se), manganese (Mn) and molybdenum (Mo) were measured. Age-related changes were observed for all measured variables except for MDA (p<0.05). A decreasing trend was detected throughout the study in thyroid hormones, T3: T4 ratio and Mn (p<0.01). Some factors decreased from birth to day 10 (Se) or day 28 (TAC and GSH) and followed by an increasing trend that extended to day 84 (p<0.01). There were significant correlations between thyroid hormones and TAC, as well as Mn levels (p<0.05). These results imply that specific age-related reference values are essential for proper interpretation of the serum level of thyroid hormones and Mn in Saanen goat kids during the first three months of life. In addition, given the high level of thyroid hormones particularly during the first days of life, and their relationship with oxidative biomarkers and trace elements, improving the antioxidant system in this critical period is essential.

Metabolomic Analysis Reveals Changes in Plasma Metabolites in Response to Acute Cold Stress and Their Relationships to Metabolic Health in Cold-Acclimatized Humans.

Cold exposure results in activation of metabolic processes required for fueling thermogenesis, potentially promoting improved metabolic health. However, the metabolic complexity underlying this process is not completely understood. We aimed to analyze changes in plasma metabolites related to acute cold exposure and their relationship to cold-acclimatization level and metabolic health in cold-acclimatized humans. Blood samples were obtained before and acutely after 10–15 min of ice-water swimming (<5 °C) from 14 ice-water swimmers. Using mass spectrometry, 973 plasma metabolites were measured. Ice-water swimming induced acute changes in 70 metabolites. Pathways related to amino acid metabolism were the most cold-affected and cold-induced changes in several amino acids correlated with cold-acclimatization level and/or metabolic health markers, including atherogenic lipid profile or insulin resistance. Metabolites correlating with cold-acclimatization level were enriched in the linoleic/α-linolenic acid metabolic pathway. N-lactoyl-tryptophan correlated with both cold-acclimatization level and cold-induced changes in thyroid and parathyroid hormones. Acute cold stress in cold-acclimatized humans induces changes in plasma metabolome that involve amino acids metabolism, while the linoleic and α-linolenic acid metabolism pathway seems to be affected by regular cold exposure. Metabolites related to metabolic health, thermogenic hormonal regulators and acclimatization level might represent prospective molecular factors important in metabolic adaptations to regular cold exposure.

Thyroid Function and Anti-thyroid Antibodies in Pediatric Anti-NMDAR Encephalitis.

Objective: Recent studies found that changes of thyroid antibodies (ATAbs), thyroid hormone, and non-thyroidal illness syndrome (NTIS) characterized by thyroid hormone inactivation with low triiodothyronine and high reverse triiodothyronine followed by suppressed thyroid-stimulating hormone (TSH) in adult anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis were associated with disease severity. This study aimed to explore thyroid function and ATAbs in pediatric anti-NMDAR encephalitis and their clinical association.Methods: We retrospectively analyzed the clinical data of 51 pediatric cases with anti-NMDAR encephalitis hospitalized in Guangzhou Women and Children's Medical Center from August 2016 to 2019.Results: A percentage of 52.9% of patients belonged to the ATAb (+) group, with 26 cases both positive for anti-thyroid peroxidase antibodies (TPOAb) and anti-thyroglobulin antibodies (TGAb), and one patient only positive for TPOAb. A percentage of 62.7% of patients had at least one abnormality in terms of FT3, free thyroxin (FT4), or TSH levels. Meanwhile, 45.1% of patients were diagnosed with NTIS. Among 25 cases retested for thyroid function 2 months after the initial test, the respectively decreased FT3 and FT4 in 13 and 11 cases on admission returned to normal or closer normal than before; TPOAb in eight cases and TGAb in 12 cases were changed from positivity to negativity. Compared with onset, the level of TPOAb and TGAb at relapse remained stable or significantly decreased, respectively. Compared with the ATAb (–) group, the ATAb (+) group had an older onset age, a higher ratio of movement disorders, elevated rate of sleep disorders, increased anti-nuclear antibody positivity rate, and higher ratio of more than one course of intravenous immunoglobulin treatment. There were no significant differences between the NTIS and non-NTIS groups in clinical characteristics.Conclusion: Anti-thyroid antibody positivity, abnormality of FT3, FT4, or TSH levels and NTIS are frequent in pediatric anti-NMDAR encephalitis. Thyroid antibody and thyroid hormone abnormalities could be improved through the course of treatment of anti-NMDAR encephalitis. Cases with ATAbs (+) are at older onset ages and more likely to be treated by intravenous immunoglobulin therapy more than once. Unlike adult anti-NMDAR encephalitis, NTIS might not be associated with the clinical characteristics of anti-NMDAR encephalitis in pediatric patients.

Are serum thyroid hormone changes in rats a reliable indicator for human neurodevelopmental effects? -Evaluation of different cases

Are serum thyroid hormone changes in rats a reliable indicator for human neurodevelopmental effects? -Evaluation of different cases

Association of serum prolactin levels and thyroid hormones with poisoned patient outcome

Background: In acute and chronic phases of severe diseases, endocrine changes occur. Some hormones, such as prolactin (PRL) and thyroid hormones, were considered predictors of ICU patients' outcomes. The present study evaluates thyroid hormone profile, serum PRL level, and their relationship with ICU poisoned patients' mortality rate.Methods: This study included 140 inpatients in the Toxicology Intensive Care Unit (TICU) who enrolled in a prospective study of a single center and observational. After admission to the ICU, the researchers collected venous blood samples from all patients directly. Concurrently, the APACHE II score was calculated. The collected samples analysis was performed based on the entire triiodothyronine (T3), thyroxine (T4), thyroid-stimulating hormone (TSH), and PRL level.Results: One hundred and forty subjects were studied, of which 109 (75.85%) were male with a mean age of 34.17 ± 14.01. One hundred and eighteen patients were survivors with a mean age of 33.29 ±13.76. In contrast, 22 patients with a mean age of 38.91 ±14.69 died. The model of PRL combined with APACHE II score (OR 1.17, 95% CI 1.06 to 1.28, P-value =0.001) was the best model for predicting post-ICU mortality in our study.Conclusions: This study’s results are consistent with the previous research, indicating a higher incidence of thyroid and PRL hormone changes in patients hospitalized in the ICU. It can be concluded that the presence of PRL based on the APACHE II score can lead us to be more precise in predicting the outcome of poisoning in hospitalized patients.

The Association of Thyroid Hormone Changes with Inflammatory Status and Prognosis in COVID-19

Background COVID-19 infection may have multiorgan effects in addition to effects on the lungs and immune system. Recently, studies have found thyroid function abnormalities in COVID-19 cases which were interpreted as euthyroid sick syndrome (ESS) or destructive thyroiditis. Therefore, in this study, we aimed to evaluate the thyroid function status and thyroid autoimmunity in COVID-19 patients. Material and Method. 205 patients were included. The medical history and laboratory parameters at admission were collected from medical records. Serum thyroid-stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), thyroid peroxidase antibody, and thyroglobulin antibody were measured, and patients were classified according to thyroid function status. Results 34.1% of the patients were euthyroid. Length of hospitalization (p < 0.001), rate of oxygen demand (p < 0.001), and intensive care unit (ICU) admission (p=0.022) were lower, and none of the euthyroid patients died. 108 (52.6%) patients were classified to have ESS, 57 were classified as mild, and 51 were moderate. The inflammatory parameters were higher in patients with moderate ESS. In cluster analysis, a high-risk group with a lower median FT3 value (median = 2.34 ng/L; IQR = 0.86), a higher median FT4 value (median = 1.04 ng/dL; IQR = 0.33), and a lower median TSH value (median = 0.62 mIU/L; IQR = 0.59) included 8 of 9 died patients and 25 of the 31 patients that were admitted to ICU. Discussion. Length of hospitalization, oxygen demand, ICU admission, and mortality were lower in euthyroid patients. Moreover, none of the euthyroid patients died. In conclusion, evaluation of thyroid function tests during COVID-19 infection may give information about the prognosis of disease.

The dose-response relationship between low-dose ionizing radiation and thyroid hormone of medical workers

Objectives To explore the dose-response relationship between low-dose ionizing radiation and thyroid hormone levels of radiation medical workers and provide theoretical basis for occupational health protection to this population. Methods Using a prospective cohort study design, we collected health examination reports on employees that worked on jobs with occupational exposure to radiation at hospital with individually dose monitoring data for 1 237 workers. The effective cumulative radiation dose was divided into three groups: 0~2.586 mSv, 2.586~3.757 mSv, 3.758~31.272 mSv by the interquartile range. The low-dose group was used as a reference to compare the changes in thyroid hormones of medical workers in different cumulative radiation dose groups. The generalized linear models and restricted cubic spline model were used to examine the association and dose-response relationship between the cumulative effective dose and changing thyroid hormones. Results There were statistically significant differences in changing thyroxine (T4) and Free triiodothyronine (FT3) levels among three different dose groups of 1 237 subjects ( P < 0.05). The results of generalized linear models analysis revealed that 2.586~3.757 mSv was a significant risk factors of changing T4, with β of 3.514 (95% confidence interval [95% CI]: 0.900~6.128) after adjusting for gender, age, working duration, occupation, medical level and smoking, while the association with changing FT3 was not observed ( P > 0.05). The restrictive cubic spline (RCS) model analysis indicated a non-linear dose-response correlation between cumulative radiation dose with changing T4 ( P = 0.023). Conclusion Longterm exposure to low-dose ionizing radiation could induce the thyroid damage among medical occupational population. And there is a dose-response relationship between cumulative radiation dose and changing thyroxine. 摘要： 目的 探宄低剂量辐射与甲状腺激素水平的剂量-反应关系, 为放射工作人员防护工作重点提供理论依据。 方法 采用前瞻性队列研宄设计, 收集 1 237 名放射工作人员健康体检报告及个人剂量监测数据。以辐射累积有效剂 量作为观察指标并按照四分位间距分 0~2.586 mSv、2.586~3.757 mSv、3.758~31.272 mSv 3 组, 低剂量组为参照, 比 较不同累积辐射剂量组放射工作人员甲状腺激素变化情况。采用广义线性模型和限制性立方样条模型分别估计累积 有效剂量与甲状腺激素变化的关联及剂量反应关系。 结果 1 237 名放射工作人员的甲状腺素 T4、FT3 水平变化在不 同剂量组间的差异有统计学意义( P < 0.05)。调整性别、年龄、工龄、职业、医疗等级和吸烟后, 广义线性模型分析显 示, 2.586~3.757 mSv ( β = 3.514, 95% CI: 0.900~6.128) 与放射工作人员 T4 水平变化显著相关, 而累积有效剂量与 FT3 水平变化无关 ( P > 0.05)。限制性立方样条分析结果显示, 累积有效剂量连续变化与 T4 水平变化呈非线性剂量反 应关系 ( P = 0.023)。 结论 长期低剂量电离辐射对放射工作人员甲状腺功能造成一定的损伤, 辐射累积有效剂量与 T4 水平变化存在剂量-反应关系。

High-Normal Thyroid Function and Recurrence of Atrial Fibrillation after Catheter Ablation: A Prospective Observational Study

Background: Thyroid function is increasingly recognized as an important modifiable factor for atrial fibrillation (AF); however, it is unclear if the changes in thyroid hormones, even within the normal range, are associated with AF recurrence after catheter ablation. Methods: Consecutive paroxysmal AF patients who underwent catheter ablation were enrolled. Patients with abnormal thyroid hormones or previous thyroid illnesses were excluded. Patients were followed for 12 months or until they presented with the first episode of atrial tachyarrhythmia after a blanking period. Results: The study included 448 patients with a mean age of 61 (14) years, and 46% were women. After a 1-year follow-up, 104 (23.2%) patients experienced atrial tachyarrhythmia recurrences after an ablation procedure. Recurrence was significantly different among quartile groups of thyroid function, with highest FT₄ and FT₃ levels associated with the greatest risk of recurrence (p < 0.001 and p = 0.024, respectively). FT₄ and FT₃ levels were independent predictors of atrial tachyarrhythmia recurrence (hazard ratio 1.07 per 1 pmol/L increase in FT₄, 95% confidence interval [CI] 1.01–1.15, p = 0.036 and 1.31 per 1 pmol/L increase in FT₃, 95% CI 1.01–1.71, p = 0.032). Conclusions: High-normal FT₃ and FT₄ levels are associated with AF recurrence after catheter ablation in this Chinese population. Attention to thyroid hormones could be valuable to assist in the management of AF.

Physiological Changes of Thyroid Hormones in Women with Osteoporosis in Iraq / Basra Province

Osteoporosis is described as sickness due to fading bone mass and microarchitecture spoilage of bone tissue leads to consolidation bone fragility and increase risk of fracture. The relationship between osteoporosis and thyroid is important by of the skeleton bones in turnout of circulating physical thyroid hormone and TSH condensation to reduced bone mineral loss in osteoporosis patients, also researcher derives that hormone thyroid and TSH scale increased bone resorption, by increase bone mineral deposition. (110) patients female transfer from provincial and civilian habitation, their ages between (55-75) years old, they pay a visit to DEXA station to measure the density. The samples of blood after diagnosis of disease were taken, then the thyroid hormones were gauged by the modern VIDAS automated quantitative device according to the methods which assay serum or plasma. The outcome appeared to decrease significantly (p≤0.05) in TSH, T3, and T4 in osteoporosis women compared with healthy women, also no significant changes occur between housing status. Thyroid hormones have significant changes in osteoporosis women matched with good health women in Iraq / Basra province.

Early-life exposure to tris (1,3-dichloro-2-propyl) phosphate caused multigenerational neurodevelopmental toxicity in zebrafish via altering maternal thyroid hormones transfer and epigenetic modifications

Tris (1,3-dichloro-2-propyl) phosphate (TDCIPP), an alternative to brominated flame retardants, might pose an exposure risk to humans and wild animals during fetal development. Our recent study suggested that short-term TDCIPP exposure during early development caused sex-dependent behavioral alteration in adults. In the present study, multigenerational neurodevelopmental toxicity upon early-life exposure of parental zebrafish was evaluated, and the possible underlying mechanisms were further explored. Specifically, after embryonic exposure (0–10 days post-fertilization, dpf) to TDCIPP (0, 0.01, 0.10, and 1.00 μM), zebrafish larvae were cultured in clean water until the sexually matured to produce progeny (F1). The results confirmed neurodevelopmental toxicity in F1 larvae characterized by changes of developmental endpoints, reduced thigmotaxis, as well as altered transcription of genes including myelin basic protein a (mbpa), growth associated protein (gap43) and synapsin IIa (syn2a). Sex-specific changes in thyroid hormones (THs) indicated the relationship of abnormal THs levels with previously reported neurotoxicity in adult females after early-life exposure to TDCIPP. Similar changing profiles of TH levels (increased T3 and decreased T4) in adult females and F1 eggs, but not in F1 larvae, suggested that the TH disruptions were primarily inherited from the maternal fish. Further results demonstrated hypermethylation of global DNA and key genes related to TH transport including transthyretin (ttr) and solute carrier family 16 member 2 (slc16a2), which might affect the transport of THs to target tissues, thus at least partially contributing to the neurodevelopmental toxicity in F1 larvae. Overall, our results confirmed that early-life TDCIPP exposure of parental fish could affect the early neurodevelopment of F1 offspring. The underlying mechanism could involve altered TH levels inherited from maternal zebrafish and epigenetic modifications in F1 larvae.

Changes in thyroid hormones and free triiodothyronine-to-free thyroxine ratio in euthyroid patients with obesity in terms of different glucose metabolism statuses

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Changes in thyroid hormones and free triiodothyronine-to-free thyroxine ratio in euthyroid patients with obesity in terms of different glucose metabolism statuses

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Changes in thyroid hormones and free triiodothyronine-to-free thyroxine ratio in euthyroid patients with obesity in terms of different glucose metabolism statuses

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Factors Affecting Thyroid Hormone Changes Over 1 Month After Birth in Preterm Newborns

Purpose: To analyze factors affecting thyroid hormone changes over 1 month after birth in preterm newborns. Methods: Thyroid hormones, including free thyroxine (fT4) and thyroid stimulating hormone (TSH) of 216 preterm newborns (mean gestational age [GA] 33.6±2.6 weeks), were retrospectively reviewed at the 1st and 4th weeks after birth. Preterm newborns were classified into three groups according to the GA (< 28 weeks, group A; 28-32 weeks, group B; 32-36 weeks, group C). The association between thyroid hormone changes and clinical factors was analyzed. Results: Preterm newborns with older GA had higher concentrations of fT4 (group A, 0.9±0.2 ng/dL; group B, 1.2±0.2 ng/dL; group C, 1.5±0.3 ng/dL) and TSH (group A, 2.7±3.2 mIU/L; group B, 4.5±3.3 mIU/L; group C, 6.0±3.8 mIU/L), both at the 1st week after birth. fT4 and TSH at the 1st week after birth were positively correlated with the GA (r=0.52, P=0.0001; r=0.30, P=0.0001) and Apgar score at 5 minutes (r=0.31, P=0.0001; r=0.28, P=0.0001). TSH concentration at the 1st week after birth was significantly lower in the abnormal brain sonogram group than in the normal brain sonogram group (4.4±3.7 vs 6.1±3.4 mIU/L, P=0.001); there were no differences at the 4th week after birth between these groups (4.2±2.6 vs 3.4±2.4 mIU/L, P=0.485). Multiple linear regression analysis revealed that GA was positively correlated with fT4 and TSH at the 1st week, and fT4 at 4th week after birth (B=0.08, SE=0.12, P=0.0001; B=0.34, SE=0.15, P=0.029; B=0.02, SE=0.01, P=0.013). Conclusion: Thyroid hormone levels in preterm newborns are mostly within the normal reference value of full-term newborns within 4 weeks of life, and are mainly affected by GA and brain ultrasound abnormalities.

Evaluation of Changes in Blood Factors and Thyroid hormones in radiology students of Kurdistan University of Medical Sciences

Evaluation of Changes in Blood Factors and Thyroid hormones in radiology students of Kurdistan University of Medical Sciences

Occupational Radiation Exposure and Changes in Thyroid Hormones in a Cohort of Chinese Medical Radiation Workers

ObjectiveThis study aimed to evaluate the association between occupational radiation exposure and changes in thyroid hormone levels among medical radiation workers. MethodsThis retrospective cohort study included 2,946 radiation workers from 20 Guangzhou hospitals. Data on general characteristics, participant radiation dosimetry, and thyroid function test results [thyroid-stimulating hormone (TSH), triiodothyronine (T3), and thyroid hormone (T4)] were extracted from dosimetry and medical records. The generalized estimating equation was used to evaluate the trend of changes in thyroid hormone levels over time and was adjusted for age, gender, and occupation. ResultsThe average annual effective dose was very low and showed a general downward trend. During the follow-up period, changes in T3 and T4 levels among radiation workers were –0.015 [95% confidence interval (CI) −0.018 to −0.012] nmol/L per year and −2.294 (95% CI −2.426 to −2.162) nmol/L per year, respectively. Thyroid hormone levels were significantly different between males and females. T3 levels in the group of upper quartile of dose were significantly higher than in the lower quartile group (P = 0.006). No significant decreased trend in thyroid hormone levels was observed with increasing average effective doses. ConclusionThyroid hormone secretion might be affected even in low-dose radiation exposure environments.

Delivery factors and neonatal thyroid hormone levels: a systematic review.

Postnatal thyroid hormone changes enable the neonate to be adapted for postnatal life. Several factors can affect this adaption. In this review, we summarized the studies that reported the association among the delivery factors and neonatal thyroid hormones and thyroid stimulating hormone. A comprehensive literature search was performed in PubMed, Web of Science, and Scopus up to March 2020, to identify the studies investigating the relationship between delivery factors, especially the mode of delivery and labor pain, and neonatal thyroid hormones and TSH. Finally, in this review study, of 157 articles obtained in the initial search, 25 eligible studies were reviewed. Various maternal, fetal/neonatal, and obstetric factors affected neonatal TSH and thyroid hormones. Among various influencing factors, mode of delivery, labor pains, and duration of labor have a strong relationship with neonatal thyroid hormones and need to be considered for interpretation of neonatal thyroid status. The majority of the studies revealed that vaginal deliveries (instrumental or natural) lead to higher levels of cord TSH compared to elective cesarean section. This can be explained by the increased secretion of catecholamine during labor. It has been suggested that blood TSH and thyroid hormone levels are affected by perinatal stress events such as maternal anxiety, labor pains, fetal distress, and other stimulants of the catecholamine response. These changes may act as the trigger to increase thyroid hormone levels for adapting of neonates in the first hours after birth. This assumption needs to be re-evaluated by performing comprehensive and well-designed studies.