Antidepressant-Resistant Depression in Patients With Comorbid Subclinical Hypothyroidism or High-Normal TSH Levels.

Thyroid function is impaired by diabetes, resulting into thyroid disorders, accompanied by the alteration of thyroid-stimulating hormone (TSH) and thyroxine (T4) levels. The aim of this study was to investigate the role of vitamin D supplementation on TSH and total T4 levels in serum of Libyan patients suffering from type 2 diabetes mellitus (T2DM) with thyroid disorders. A total of 180 subjects were recruited and distributed into two groups: 80 participants in control group (43 females and 37 males), with an age range of 26-72 years, and 100 participants in T2DM patient group (54 females and 46 males), with an age range of 26-63 years. Each T2DM patient received a monthly intramuscular injection of 200000 ng/ml vitamin D for three months. Glucose, vitamin D, total T4 and TSH levels were determined in serum samples of healthy subjects and of T2DM patients (pre- and post-administration of vitamin D). After the T2DM group received vitamin D supplementation, the mean of vitamin D level increased in the T2DM, while the mean of glucose level decreased. Most importantly, the mean of total T4 level for patients increased significantly (p ˂ 0.05) from 1.34 to 8.23 mg/dL, both of which were lower than the control group mean 10.99 mg/dL. In contrast, the mean of TSH level for patients decreased significantly (p ˂ 0.05) from 11.77 to 2.71 mU/L, and both values were greater than the control group mean 2.01 mU/L. ANOVA results showed that age, gender, and body mass index had no significant individual interactions (p > 0.05) with vitamin D supplementation on total T4 and TSH levels. Vitamin D supplementation had a beneficial role on total T4 and TSH levels in serum of Libyan T2DM patients with thyroid disorders. Keywords: T2DM, thyroid disorder, total T4, TSH, vitamin D supplementation, ANOVA, t test.

Introduction: Hypothyroidism, one of the most common thyroid gland disorders, can cause electrolyte disturbances in the body. Hypothyroidism can alter mineral metabolism by changing the levels of serum calcium and magnesium. Therefore, it is essential to study any abnormalities in calcium and magnesium metabolism in patients with hypothyroidism. Aim: The aim of this study was to assess the levels of calcium and magnesium in patients with hypothyroidism and to study the correlation between Thyroid Stimulating Hormone (TSH), fT3, and fT4 with calcium and magnesium in subclinical and Overt Hypothyroidism (OH). Materials and Methods: This cross-sectional study was held from August 2019 to January 2020 in the Department of Biochemistry, BS Medical College, Bankura. A total of 150 subjects were included in the study, distributed equally among three groups: euthyroidism, subclinical hypothyroidism, and OH. Serum TSH, fT3, fT4, calcium, and magnesium levels were determined in the laboratory, and the data obtained were statistically analysed using ANOVA test and Pearson’s correlation test. Results: Out of a total of 150 subjects, 61 were female, among whom 23 had subclinical hypothyroidism and 21 had OH. There were significant differences in the mean levels of TSH, fT3, fT4, calcium, and magnesium between the SCH, OH, and euthyroid groups. The study showed that the mean serum calcium level was significantly lower in SCH and OH compared to euthyroids, while the level of serum magnesium was significantly increased in SCH and OH compared to euthyroid. There was a statistically significant negative correlation between TSH and serum calcium in both OH and SCH, while a statistically significant positive correlation was observed between TSH and serum magnesium levels in both groups. Conclusion: The present study revealed that serum magnesium levels were high while serum calcium levels were low in both subclinical hypothyroidism and OH when compared to euthyroid subjects. Additionally, calcium levels negatively correlated with TSH, while magnesium levels positively correlated with TSH levels.

BackgroundDerangements in thyroid hormone levels can cause multiple complications in the mother and the foetus. Thyroid stimulating hormone (TSH) and free thyroxine (free T4 or FT4) levels are used to screen for maternal thyroid dysfunction; these should be compared with population based trimester-specific reference ranges. Our goal was: to determine the prevalence of various thyroid derangements, in early pregnancy, according to the current reference ranges available; to determine the need for trimester specific reference ranges for the local population.MethodsA multi-centric, cross sectional population survey was conducted in Lahore, Pakistan. Serum TSH and FT4 levels were measured at the hormone lab of the Pathology department of Combined Military Hospital (CMH) Lahore. The results were entered and analysed using Statistical Package for the Social Sciences (SPSS) version 23. ResultsIn the 293 women sampled, mean FT4 and TSH levels were 15.03 (±5.62) pmol/L and 2.53 (±6.82) mIU/L respectively. According to the laboratory specific reference ranges, the prevalence of overt hyperthyroidism was 4.10%, (mean TSH= 0.03mIU/L); subclinical hyperthyroidism was 16.38%, (mean TSH= 0.17mIU/L); normal 70.65%, (mean TSH = 1.29mIU/L); subclinical hypothyroidism 4.44%, (mean TSH= 15.11mIU/L); overt hypothyroidism 4.44%, (mean TSH = 20.60mIU/L).ConclusionOur study showed a significant prevalence of thyroid dysfunction in the first trimester of pregnancy, and therefore highlights the need for more rigorous thyroid screening of women, in early pregnancy. There is a need to monitor these women in order to reduce maternal and foetal complications. Trimester specific reference ranges for thyroid hormones need to be developed in Pakistan.

Thyroid bone disease

Thyroid Disorders.

BackgroundMetabolic dysfunctions characteristic of overt hypothyroidism (OH) start at the early stage of subclinical hypothyroidism (SCH). Na+/K+-ATPase (the sodium pump) is a transmembrane enzyme that plays a vital role in cellular activities in combination with membrane lipids. We evaluated the effects of early changes in thyroid hormone and membrane cholesterol on sodium pump activity in SCH and OH patients.MethodsIn 32 SCH patients, 35 OH patients, and 34 euthyroid patients, sodium pump activity and cholesterol levels in red blood cell membranes were measured. Serum thyroxine (T4) and thyroid stimulating hormone (TSH) levels were measured using enzyme-linked immunosorbent assays. Differences in their mean values were analysed using post hoc analysis of variance. We assessed the dependence of the sodium pump on other metabolites by multiple regression analysis.ResultsSodium pump activity and membrane cholesterol were lower in both hypothyroid groups than in control group, OH group exhibiting lower values than SCH group. In SCH group, sodium pump activity showed a significant direct dependence on membrane cholesterol with an inverse relationship with serum TSH levels. In OH group, sodium pump activity depended directly on membrane cholesterol and serum T4 levels. No dependence on serum cholesterol was observed in either case.ConclusionDespite the presence of elevated serum cholesterol in hypothyroidism, membrane cholesterol contributed significantly to maintain sodium pump activity in the cells. A critical reduction in membrane cholesterol levels heralds compromised enzyme activity, even in the early stage of hypothyroidism, and this can be predicted by elevated TSH levels alone, without any evident clinical manifestations.

Background: Metabolic syndrome (MetS) is a cluster of metabolic abnormalities characterized by central obesity, hyperglycemia plus insulin resistance, hypertriglyceridaemia plus low high density lipoprotein (HDL) cholesterol and hypertension. This cluster of metabolic syndrome is associated with some of the endocrine disorders prominently thyroid dysfunction. Thyroid dysfunction and metabolic syndrome are both associated with cardiovascular disease risk conversely increasing both morbidity and mortality. Objectives: This study was carried out to evaluate thyroid function in patients with metabolic syndrome and to assess its relationship with the components of metabolic syndrome in a tertiary care hospital. Methods: A cross sectional study was carried out among metabolic syndrome patients attending Hormone and Diabetes clinic in a tertiary care hospital, Dhaka, Bangladesh during June 2019 to March 2020. We included 346 patients who fulfilled National Cholesterol Education Program-Adult Treatment Panel (NCEP ATP) III criteria. Anthropometric parameters include; height, weight and waist circumference were measured and blood pressure were taken in standard conditions. Fasting blood samples were analyzed to measure glucose, triglyceride (TG), high density lipoprotein (HDL) cholesterol and thyroid hormones [Thyroid stimulating hormone (TSH) and Free Thyroxine (FT4)]. Patients categorized as euthyroid if all thyroid hormone levels fell within normal reference range [TSH: 0.47-5.0mIU/L; FT4: 0.71-1.85 ng/dL]. Subclinical hypothyroidism (SCH) was considered if TSH >5.0mIU/L and free T4 is within normal reference value (0.71-1.85 ng/dL). Conversely, overt hypothyroidism was diagnosed if TSH >5.0 mIU/L and freeT4<0.71 ng/dL. Results: Among study population 22.8% were males and 77.2% were females, with mean age of 42.61±9.13 years. Average body mass index (BMI) of the study subjects was 26.37±3.78 kg/m². Thyroid dysfunction was seen in 47.1% of metabolic syndrome patients. The prime thyroid dysfunction was subclinical hypothyroidism (34.4%) followed by overt hypothyroidism (12.7%). Thyroid dysfunction was much common in females (37.3%) than males (9.9%) but was not statistically significant; [p=0.19]. Triglyceride showed significant positive correlation with TSH level (r=0.168, p<0.05) but negative correlation with free T4 (r=-0.200, p=<0.001). However, HDL cholesterol showed significant negative correlation with TSH level (r=-0.150, p<0.05). Conclusions: Our study recognizes thyroid dysfunction in metabolic syndrome patients; subclinical hypothyroidism was the commonest followed by overt hypothyroidism. The current study also correlates thyroid function with some components of metabolic syndrome (high density lipoprotein cholesterol and triglycerides).

Thyroid hormones modulate the cardiovascular system. However, the effects of subclinical thyroid dysfunction and euthyroidism on cardiac function remain unclear. We investigated the association between left ventricular (LV) diastolic dysfunction and subclinical thyroid dysfunction or thyroid hormones within the reference range. This cross-sectional study included 26,289 participants (22,197 euthyroid, 3,671 with subclinical hypothyroidism, and 421 with subclinical thyrotoxicosis) who underwent regular health check-ups in the Republic of Korea. Individuals with thyroid stimulating hormone (TSH) levels > 4.2 µIU/mL and normal free thyroxine (FT4, 0.78–1.85 ng/dL) and triiodothyronine (T3, 76–190 ng/dL) levels were defined as having subclinical hypothyroidism. Individuals with serum TSH levels < 0.4 µIU/mL and normal FT4 and T3 levels were defined as having subclinical thyrotoxicosis. The cardiac structure and function were evaluated using echocardiography. LV diastolic dysfunction with normal ejection fraction (EF) was defined as follows: EF of > 50% and (a) E/e’ ratio > 15, or (b) E/e’ ratio of 8–15 and left atrial volume index ≥ 34 mL/m2. Subclinical hypothyroidism was significantly associated with cardiac indices regarding LV diastolic dysfunction. The odds of having LV diastolic dysfunction was also increased in participants with subclinical hypothyroidism (adjusted odds ratio [AOR] 1.36, 95% confidence interval [CI], 1.01–1.89) compared to euthyroid participants. Subclinical thyrotoxicosis was not associated with LV diastolic dysfunction. Among the thyroid hormones, only serum T3 was significantly and inversely associated with LV diastolic dysfunction even within the normal range. Subclinical hypothyroidism was significantly associated with LV diastolic dysfunction, whereas subclinical thyrotoxicosis was not. Serum T3 is a relatively important contributor to LV diastolic dysfunction compared to TSH or FT4.

Objectives From previous studies, it is known that the association between fibromyalgia and thyroid autoimmunity diseases exists. On the other hand, it was recently suggested that in many cases thyroid hormone treatment might be unnecessary. The aim of our study is to explore the thyroid hormone treatment among fibromyalgia patients in cross-sectional study based on data from fibromyalgia patients in the city of Nokia Health Center Finland. Method Fibromyalgia patients were searched from the electronic patient records. Patients filled five questionnaires and information from electronic patient records was gathered. Information from thyroid hormone treatment and thyroid-stimulating hormone (TSH) and free thyroxine (T4-V) levels were gained from patient records. We used the Finnish guidelines for hypothyroidism: TSH level over 4.2 mU/l was defined as subclinical hypothyroidism if the T4-V level was normal. The T4-V level under 11.0 pmol/L was defined as central hypothyroidism if TSH level was normal or low. TSH level over 4.2 mU/l and T4-V level under 11.0 pmol/L was defined as overt hypothyroidism. TSH levels between 0.27–4.2 mU/l and T4-V levels between 11.0–22.0 pmol/L were defined as normal thyroid function. Cross-tabulation and Chi-Square test were used when categorical variables were present and two-sample t-test was performed with variables following a normal distribution. Results Altogether 208 patients were identified. 103 patients returned mailed questionnaires and were included in the study. 96 patients had fibromyalgia according to ACR 2010 criteria. From that group 33 (34%) had thyroid hormone treatment and 63 (66%) had not. Statistical significance was not found between those taking thyroid hormone replacement and those not taking it in functional ability (p=0.36) or depression (p=0.71). From those 33 patients with thyroxine treatment, 16 had information regarding the initial TSH and T4-V levels before thyroid hormone treatment: Ten (63%) patients had hypothyroidism based on the laboratory tests. Subclinical hypothyroidism was present in six cases, central hypothyroidism in three cases and as overt hypothyroidism in one case. Of 16 patients with thyroid hormone treatment, six patients (37%) had normal thyroid function at the beginning of the treatment. Conclusions The occurrence of thyroid hormone treatment was much higher in our study population (34%) than in the previous study in Japan (8%). In our study, over one third of the fibromyalgia patient using thyroid hormone treatment – whose initial thyroid hormone levels were available – did have normal thyroid function. There are likely several explanations to this. One might be that one of the main symptoms of fibromyalgia is fatigue, which also is common with hypothyroidism. Patients are aware of this and some may want to try out the thyroid hormone treatment even though their thyroid function is normal. Further studies are needed to confirm the potential association between functional syndromes like fibromyalgia and inappropriate thyroid hormone treatment.

Hypothyroidism in Clinical Practice

The term "euthyroid sick syndrome" (ESS) has been used to describe a pattern of thyroid hormone changes during the course of critical illness in adult patients without thyroid disease, often associated with reduced thyroid hormone secretion. To describe the thyroid hormone profile in full-term newborns critically ill compared with thyroid hormone profile of healthy infants, and determine if alterations could be related to the severity of the disease and outcome. A cross-sectional, observational, and prospective study of full-term infants admitted to the neonatal intensive care unit (NICU) of the Hospital de Pediatría J.P. Garrahan between July 2007 and April 2008. Serum T3, T4, and thyroid stimulating hormone (TSH) levels were measured at admission and severity of the disease was evaluated through SNAP, lactic acid, respiratory assistance and number of organs affected. Sick newborns showed significantly lower T3 and T4 levels compared with healthy infants [T3: -0.97 μg/dL (95% CI -0.89, -1.13) and T4: -4.37 μg/dL (95% CI -2.95, -5.78)]. Only 29 out of 94 (31%) infants presented a normal profile; 37 (39%) infants showed isolated low T3 levels, 20 (21%) infants had low T3 and T4 levels and eight (9%) infants had low TSH, T3, and T4. Of this latter group, five of eight (62%) children died suggesting a significantly higher risk of death for patients with low T3 associated with low T4 and TSH [Risk ratio (RR) 10.75 95% CI 3.93, 29]. Full-term sick newborns frequently have lower thyroid hormone levels than healthy ones. These observed thyroid hormones changes might be related to the underlying disease and could be used as a prognostic marker of the severity and fatal outcome of the patient.

Endocrinology| September 01 2008 “False-Positive” Newborn Thyroid Screen May Predict Future Subclinical Hypothyroidism AAP Grand Rounds (2008) 20 (3): 31–32. https://doi.org/10.1542/gr.20-3-31-a Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation “False-Positive” Newborn Thyroid Screen May Predict Future Subclinical Hypothyroidism. AAP Grand Rounds September 2008; 20 (3): 31–32. https://doi.org/10.1542/gr.20-3-31-a Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search nav search search input Search input auto suggest search filter All PublicationsAll JournalsAAP Grand RoundsPediatricsHospital PediatricsPediatrics In ReviewNeoReviewsAAP NewsAll AAP Sites Search Advanced Search Topics: false-positive results, subclinical hypothyroidism, thyroid screening, thyrotropin, hyperthyrotropinemia, thyroid function tests Source: Leonardi D, Polizzotti N, Carta A, et al. Longitudinal study of thyroid function in children with mild hyperthyrotropinemia at neonatal screening for congenital hypothyroidism. J Clin Endocrin Metab. Rapid Electronic Publication first published on April 29, 2008; doi:10.1210/jc.2007-2612 To better understand the natural history of children with unexplained transient increase in thyroid stimulating hormone (TSH) in the newborn period, researchers from the University of Catania in Catania, Italy, followed children who had a “false positive” newborn thyroid screen into late childhood. This study was an extension of previously published work describing children with transient increase in TSH who, when studied at 16–44 months of age, demonstrated a high incidence (50%) of subclinical hypothyroidism.1 Infants with Down syndrome, prematurity, small for gestational age, and newborns of thyroid autoimmunity-positive mothers were excluded. Thyroid function and morphology in children with transient unexplained hyperthyrotropinemia in infancy were compared with control children who had normal newborn TSH levels at three time periods: age 16–44 months, age 4.1–6.6 years, and age 7.2–9.5 years. Measures of function included TSH, free T4 (FT4), free T3 (FT3), anti-thyroglobulin (anti-Tg), and anti-thyroperi-oxidase (anti-TPO) antibodies. Morphology was evaluated by ultrasound and thyroid volume was calculated and compared with reference values. A total of 44 children were followed until an average age of eight years. At age 16–44 months all children had a normal serum FT4, but mean serum TSH and FT3 levels were significantly higher than those of controls. Based on TSH levels at this time, children were divided in two groups: group 1 (16 patients) had normal serum TSH levels of <4.0mU/L and group 2 (28 patients) had slightly elevated serum TSH (4.0–10.1 mU/L). Levothyroxine treatment was given to reduce TSH in 20 of 28 children in group 2. At age 4.1–6.6 years, serum FT4 was within normal range in all children, with average values similar in groups 1 and 2. Serum TSH was within normal range in all 16 group 1 children and in nine of 28 group 2 children (group 2a); however, when the 25 children with normal serum TSH were compared with the control group, their average TSH levels were significantly higher. In the remaining 19 of 28 group 2 children, serum TSH was persistently elevated (group 2b). FT3 values were significantly higher compared with controls. Anti-thyroid antibodies (anti-TPO and/or anti-Tg) were slightly positive in 11 of 44 children in early childhood; however, they were weakly positive in only one child in group 2 at 30 months of age. At age 7.2–9.5 years, TSH serum values remained in the normal range in all group 1 children and in the nine group 2a children. Of the 19 group 2b children, TSH remained elevated in 14 but normalized in five children. Of the eight children treated with levothyroxine, seven had persistent elevation of TSH. Out of these seven children, six were determined to have genetic and/or morphological abnormalities of the thyroid as the possible cause of their... You do not currently have access to this content.

Aim: This large-scale Japanese population study was done to evaluate the relation between the serum thyroid stimulating hormone (TSH) level and renal function. Methods: Among 1,374 residents who attended a free public physical examination between 2010 and 2011, we evaluated the data of 888 for whom the serum TSH level and estimated glomerular filtration rate (eGFR) were successfully measured. The participants were divided into three groups by TSH level (normal TSH, ≤2.4; high-normal TSH, 2.5-4.4; subclinical hypothyroid, ≥4.5 μIU/L). Multiple linear regression analysis adjusted for cardiovascular risk factors was done to determine the relation between serum TSH level and renal function. Results: The mean ± SD TSH level was 2.0±1.4 μIU/mL. Of the participants, 75.9% (n=674) had a normal TSH level, 17.9% (n=159) were high-normal TSH, and 6.2% (n=55) were subclinical hypothyroid. The mean eGFR significantly decreased with increased TSH level (normal TSH group, 79.3±14.1; high-normal TSH group, 77.4±13.0; subclinical hypothyroid group; 72.3±12.2 mL/min/1.73m2: P for trend &lt;0.01). Multiple linear regression analysis extracted log-transformed TSH level as an independent factor correlated with eGFR in the high-normal TSH group (beta=-0.18, P=0.02). Conclusions: The eGFR level significantly decreased with increased TSH level. Significant correlation between TSH and eGFR levels was found only in high-normal TSH individuals. Even in healthy individuals, increase risk of chronic kidney disease could be started from high-normal TSH level.

Thyroid hormones are necessary for the normal functioning of physiological systems. Therefore, knowledge of any factor (whether genetic, environmental or intrinsic) that alters the levels of thyroid-stimulating hormone (TSH) and thyroid hormones is crucial. Genetic factors contribute up to 65% of interindividual variations in TSH and thyroid hormone levels, but many environmental factors can also affect thyroid function. This review discusses studies that have analyzed the impact of environmental factors on TSH and thyroid hormone levels in healthy adults. We included lifestyle factors (smoking, alcohol consumption, diet and exercise) and pollutants (chemicals and heavy metals). Many inconsistencies in the results have been observed between studies, making it difficult to draw a general conclusion about how a particular environmental factor influences TSH and thyroid hormone levels. However, lifestyle factors that showed the clearest association with TSH and thyroid hormones were smoking, body mass index (BMI) and iodine (micronutrient taken from the diet). Smoking mainly led to a decrease in TSH levels and an increase in triiodothyronine (T3) and thyroxine (T4) levels, while BMI levels were positively correlated with TSH and free T3 levels. Excess iodine led to an increase in TSH levels and a decrease in thyroid hormone levels. Among the pollutants analyzed, most studies observed a decrease in thyroid hormone levels after exposure to perchlorate. Future studies should continue to analyze the impact of environmental factors on thyroid function as they could contribute to understanding the complex background of gene–environment interactions underlying the pathology of thyroid diseases.

Background: A number of researches have reported that thyroid hormones are associated with obesity. However, the relationship of serum levels of thyroid hormones in the normal range with obesity and parameters of obesity in women of childbearing age remains controversial. The purpose of this study was to examine serum levels of thyroid hormones within the normal range in obese Chinese women of reproductive age and to investigate the relationship between concentration of thyroid hormones and indices of obesity, including body mass index (BMI), waist-to-hip ratio (WHR), insulin resistance, blood glucose, blood lipids, and blood pressure. Methods: One hundred fifty-one obese women of reproductive age and 160 nonobese women of reproductive age were enrolled in this study. Serum levels of thyroid-stimulating hormone (TSH) of all subjects were within the normal reference range (0.35-4.94 mIU/L). The serum levels of free triiodothyronine (FT3), free thyroxine (FT4), and TSH, height, body weight, BMI, waist and hip circumferences, WHR, fasting blood glucose (FBG), fasting insulin (FI), homeostasis model assessment of insulin resistance (HOMA-IR), total triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were measured in all subjects. Quantile regression analysis was used to analyze the associations of serum levels of FT3, FT4, and TSH with values of BMI, WHR, FBG, FI, HOMA-IR, TG, TC, LDL-C, HDL-C, SBP, and DBP. Results: In the group of obese women, serum levels of FT4 were lower (P < 0.001) and serum levels of TSH were higher (P < 0.001) compared with nonobese controls. After adjusting for covariables, quantile regression analysis showed that serum levels of FT4 were inversely associated with BMI values between the quantile levels of 0.29 and 0.60 of BMI (i.e., BMI level of 22.49 and 28.31 kg/m2, respectively). Meanwhile, we found that serum levels of TSH positively correlated with BMI values after the quantile level of 0.51 (i.e., BMI level of 27.06 kg/m2), positively associated with TC after the quantile level of 0.6 (i.e., TC level of 4.86 mM), and positively associated with LDL-C after the quantile level of 0.39 (i.e., LDL level of 1.96 mM). No significant associations were found between serum levels of thyroid hormones and values of WHR, FBG, FI, HOMA-IR, TG, HDL-C, SBP, and DBP. Conclusions: FT4 and TSH play an important role in regulating the weight in women with normal thyroid function during their reproductive years. Women with decreased serum FT4 or increased serum TSH levels have a higher risk of developing obesity. Besides, TSH has a significant influence on metabolism of blood lipids. Women with higher serum levels of TSH have a higher risk of incidence of lipid metabolism disorders.