Subclinical Thyroid Disorders Research Articles

Thyroid Hormone Signaling in Retinal Development and Function: Implications for Diabetic Retinopathy and Age-Related Macular Degeneration.

Thyroid Hormones (THs) play a central role in the development, cell growth, differentiation, and metabolic homeostasis of neurosensory systems, including the retina. The coordinated activity of various components of TH signaling, such as TH receptors (THRs) and the TH processing enzymes deiodinases 2 and 3 (DIO2, DIO3), is required for proper retinal maturation and function of the adult photoreceptors, Müller glial cells, and pigmented epithelial cells. Alterations of TH homeostasis, as observed both in frank or subclinical thyroid disorders, have been associated with sight-threatening diseases leading to irreversible vision loss i.e., diabetic retinopathy (DR), and age-related macular degeneration (AMD). Although observational studies do not allow causal inference, emerging data from preclinical models suggest a possible correlation between TH signaling imbalance and the development of retina disease. In this review, we analyze the most important features of TH signaling relevant to retinal development and function and its possible implication in DR and AMD etiology. A better understanding of TH pathways in these pathological settings might help identify novel targets and therapeutic strategies for the prevention and management of retinal disease.

A Prospective Cross-Sectional Study on Drug Adherence, Prescription Patterns, Associated Comorbidities and Quality of Life in Patients with Sub-clinical Thyroid Disorders

A Prospective Cross-Sectional Study on Drug Adherence, Prescription Patterns, Associated Comorbidities and Quality of Life in Patients with Sub-clinical Thyroid Disorders

Subclinical thyroid dysfunction and the risk of incident atrial fibrillation: A systematic review and meta-analysis.

Thyroid hormones act on the cardiovascular system directly by modulating its function and indirectly by transcriptional regulation of gene expression in the heart and the vasculature. Studies have shown associations between overt and subclinical thyroid disorders and cardiovascular outcomes. The aim of this study was to perform a systematic review and meta-analysis to assess the potential relationships between subclinical hyper- and hypothyroidism and risk of atrial fibrillation (AF), and post-operative AF. MEDLINE and Scopus databases were searched from inception to 18th February 2023 for randomised controlled trials, case-control studies, and cohort studies which assessed the relationship between subclinical thyroid dysfunction and incident AF events. Risk of bias and the quality of evidence were assessed using the RoBANS tool and GRADE approach, respectively. Meta-analysis was conducted in Review Manager 5.4 using the Mantel-Haenszel statistical method and a random-effects model. Data are presented as risk ratios with 95% confidence intervals. Statistical heterogeneity amongst studies was assessed by the chi-squared (χ2) test and I2 statistic. p≤0.05 were considered significant. A total of 6467 records were identified, of which 10 cohort studies met the inclusion criteria. Both subclinical hyperthyroidism and subclinical hypothyroidism were associated with an increased risk of incident AF (risk ratio (RR), 1.99; 95% confidence interval (CI), 1.43-2.77; n = 5 studies; p<0.0001 and RR, 1.19; CI, 1.03-1.39; n = 7 studies; p = 0.02, respectively). Subgroup analysis for post-operative AF revealed marked heterogeneity between studies (I2 = 84%) and association with subclinical hypothyroidism was not significant (RR, 1.41; CI, 0.89-2.22; n = 3 studies; p = 0.15). The current evidence suggests that both subclinical hyperthyroidism and subclinical hypothyroidism are associated with increased risk of incident AF. Further investigation is required to determine potential causal links that would guide future clinical practice.

Autoimmune thyroid status in subclinical thyroid disorders in patients attending a tertiary care center in Nepal: a hospital-based cross-sectional study

BackgroundThyroid dysfunction is the leading endocrine disorder worldwide. Iodine deficiency disorders, which were once the major etiology of thyroid dysfunctions, now have been succeeded by autoimmune thyroid diseases with the rise in aberrant salt ionization protocols. This study endeavors to access the level of thyroid autoantibodies viz. anti-thyroid peroxidase (anti-TPO), anti-thyroglobulin (TGA), and anti-thyroid stimulating hormone receptor (TRAb) in individuals with subnormal thyroid profiles.MethodsThis hospital-based cross-sectional study was conducted at the Department of Clinical Biochemistry, Tribhuvan University for a period of six months. Using non-probability (purposive) sampling method, a total of 60 patients were enrolled with subnormal thyroid profiles to include the population who have not yet started medication. Thyroid hormones (free T3, free T4, TSH) and thyroid antibodies (anti-TPO, TGA, and TRAb) were measured. For non-parametric data, Chi-square test and Kruskal-Wallis test were used. Spearman’s correlation was done to determine the association between variables.ResultsOut of 60 participants, the majority of the population between 25 and 44 years were diagnosed with thyroid dysfunction with female preponderance. Among all, 40% (n = 24) had subclinical hyperthyroid states while, 60% (n = 36) had subclinical hypothyroid states, and 75% (n = 45) of the total exhibited positive thyroid antibodies. In subclinical hypothyroid patients with TSH above 10 µIU/ml, anti TPO (58.5%) and TGA (66.7%) positivity were highly prevalent. On the other hand, TRAb was exclusively positive in hyperthyroid condition (50% among the group) which is by far the first of its kind reported in Nepal.ConclusionThe rise in autoimmune thyroid disease among the Nepalese population infers that addressing iodine deficiency simply through salt iodinization may not be adequate to deal with the rising burden of thyroid disorders, especially in iodine-depleted areas. Also, the increasing prevalence of thyroid autoantibodies positivity in subclinical hypothyroidism in the Nepalese population accounts for the arduous screening and monitoring of autoimmune thyroid disorders in Nepal.

Prevalence of Subclinical Thyroid Disorders in Jazan Region, Saudi Arabia

Prevalence of Subclinical Thyroid Disorders in Jazan Region, Saudi Arabia

Prevalence of overt and subclinical thyroid dysfunction in pregnant women and outcome in a tertiary care centre

Aim: To know the prevalence of overt and subclinical thyroid disorders in Indian pregnant women and to know the effect of overt and subclinical thyroid dysfunction on maternal and fetal outcome.&#x0D; Materials and methods: This study was conducted at the Government Maternity Hospital, sultan bazaar, Osmania medical college, Hyderabad over a period of 15 months from august 2016 to October 2017. 1000 pregnant women who attended the antenatal clinic were screened for the thyroid dysfunction. Serum TSH level estimated. fT3, fT4 and anti TPO Ab levels were estimated if the TSH level was abnormal. Patients were managed accordingly and followed till the delivery. Maternal and fetal outcome recorded.&#x0D; Results: It was a prospective study done on 1000 antenatal women. Prevalence of thyroid disorder in this study was 11.3%. Prevalence of subclinical, overt hypothyroidism, subclinical and overt hyperthyroidism was 9.4%, 1.4%, 0.4% and 0.1% respectively. Subclinical hypothyroidism was associated with complications like preeclampsia (13.8%), Anaemia (15.95%), preterm delivery (6.38%), Intrauterine growth restriction (4.25%), low birth weight (12.76%) and Intrauterine fetal death)(2.12%). Overt hypothyroidism was associated with complications like Preeclampsia (14.28%), anaemia (21.4%), Preterm delivery (14.28%), intrauterine growth restriction (14.28%), low birth weight (21.4%) and Intrauterine fetal death (7.14%). Incidence of CD was 18.05% in women with hypothyroidism. Subclinical hyperthyroidism was associated with complications like Preeclampsia, Preterm delivery, Intrauterine growth restriction, Intrauterine fetal death.&#x0D; Conclusion: Thyroid disorders in pregnancy are significantly associated with both maternal and fetal complications and adversely affect the outcome of pregnancy. Hence, early identification of thyroid disorders and timely initiation of treatment is essential

PREVALENCE OF DYSLIPIDEMIA AND ASSESSMENT OF BLOOD PRESSURE IN PATIENTS WITH SUBCLINICAL HYPOTHYROIDISM IN A TERTIARY CARE HOSPITAL - A CASE CONTROL STUDY

Introduction: The THYROID gland has been incriminated to cause a spectrum of diseases that involve almost every system of the human body. Subclinical thyroid disorders can be rightly said to be the forerunners of these clinical scenarios. One pole constitutes subclinical hypothyroidism, the other end being subclinical hyperthyroidism. 'Subclinical hypothyroidism' is dened as a condition with elevated serum TSH and normal serum T3 and T4 in the absence of overt clinical signs and symptoms. It is quite common in the community. Estimation of the prevalence ofAims: dyslipidemia among cases of subclinical hypothyroidism and Estimation of the prevalence of hypertension among cases of subclinical hypothyroidism. The present study was Observational study. This Study was conducted from January 2012 to JuneMaterials And Methods: 2014(18 months) at N.R.S Medical College and Hospital, Kolkata. 100 patients were included in this study. In this study, SH has beenResult: found to be more prevalent among elderly female.81% of total SH cases were female and 61% of the cases were aged above 50 years. Most (70%) of the SH cases had TSH value &gt; 10 micro IU/ml. These ndings correlate with the results of the Wickham survey, although the prevalence of cases with higher TSH value was more than that of the Colorado Thyroid Disease Prevalence Study. Hypertension was more prevalentConclusion: among SH cases than control population. Systolic and diastolic both blood pressure means were higher among SH cases although diastolic blood pressure was more affected. Mean arterial blood pressure was also higher among SH cases than euthyroid control.

Functional (Psychogenic) Seizures are Associated with Thyroid Disorders

Objective: We investigated medical comorbidities in patients with functional seizures (FS) and those with epilepsy (idiopathic generalized epilepsies [IGEs] or temporal lobe epilepsy [TLE]). We hypothesized that the nature of medical comorbidities differs between these three groups. This might be helpful to postulate on the pathophysiology of FS. Materials and Methods: In a retrospective study, all adult patients with a diagnosis of IGE, TLE, or FS were recruited at the outpatient epilepsy clinic at Shiraz University of Medical Sciences, Iran, from 2008 until 2020. The three groups of patients were matched with regard to their age. Age, sex, and medical comorbidities were registered routinely for all patients at the time of the first visit. Results: Nine hundred and sixty-six patients were studied (254 patients with IGE, 467 persons with TLE, and 245 individuals with FS). The groups differed significantly with regard to having medical comorbidities. The most striking difference was comorbid thyroid disorders; this was more common among patients with FS. The diagnosis of FS was independently significantly associated with thyroid disorder comorbidity (odds ratio: 2.77, 95% confidence interval: 1.06–7.23; P = 0.038). Conclusion: Thyroid disorders are significantly associated with FS. We can make the following suggestions to advance the field: a. It is necessary to reproduce this observation in larger multicenter studies; b. We recommend to evaluate thyroid function in all patients with FS; c. It might be helpful to design clinical trials to investigate whether correction of any clinical or subclinical thyroid disorders changes the treatment outcome in patients with FS.

Substantially elevated TSH, not traditional clinical subclinical thyroid disorder groupings, are associated with smaller LDL-P mean size: ELSA-Brasil

LDL appears to drive atherogenesis in overt hypothyroidism, but in subclinical dysfunction, its role is not completely elucidated. The aim of this study was to evaluate subfractions of LDL in subclinical (SC) thyroid disorders. Individuals were divided into three groups by baseline thyroid function (SC hypothyroidism, euthyroidism, and SC hyperthyroidism). LDL particle (LDL-P) subfractions were analyzed by Nuclear Magnetic Resonance (NMR) spectroscopy. The association between LDL-P subfractions and thyroid groups and quintiles was evaluated by linear regression models. We evaluated 3304 participants (54.1% women, 51.2% white, mean age 50.6±8.7 years). In the univariate analysis, small LDL particle concentrations (SLDL-P) were not different between SC hypo- and hyperthyroidism compared to euthyroid individuals (p=0.485 and p=0.314, respectively). Large LDL-P (LDL-P) levels also did not differ in SC hyperthyroidism and SC hypothyroidism compared to euthyroidism (p=0.698 and 0.788 respectively). Intermediate LDL-P levels were not different across the groups. These numbers did not materially change in multivariate analysis. However, we also analyzed LDL subfractions according to quintiles of TSH. We showed that in the higher TSH quintile LDL subfractions presented a significantly smaller mean size of LDL subfractions compared to the first quintile. SC thyroid disorders are not associated with significant changes in LDL-P subfractions measured by NMR spectroscopy. However, it seems that the LDL mean size decreases as TSH levels increase, which may represent a more atherogenic lipid profile.

Meta-analysis on the Association Between Thyroid Hormone Disorders and Arterial Stiffness.

ContextAortic stiffness is an emerging predictor of cardiovascular morbidity and mortality. Current data about the effect of subclinical and overt thyroid hormone disorders on aortic stiffness are often conflicting.ObjectivePrimary outcome was to investigate if subclinical and overt thyroid hormone disorders were associated with aortic stiffness. Secondary outcome was to identify disease effect modifiers.MethodsData sources were PubMed, Google Scholar, SCOPUS, Web of Sciences, and the Cochrane Library. Eligible studies included reports of pulse wave velocity (PWV), which is the gold standard method for measuring aortic stiffness, in patients with subclinical and overt thyroid disorders. Two investigators independently identified eligible studies and extracted data. Pooled mean difference was the summary effect measure. Data were presented in forest plots with outlier and influential case diagnostics. Univariate meta-regression analysis was used to identify effect modifiers.ResultsEleven observational studies were selected, including 1239 patients with subclinical hypothyroidism, 81 patients with overt hypothyroidism, 338 patients with thyrotoxicosis, and 12 715 controls. PWV was significantly higher in subclinical (P < .001) and overt hypothyroidism (P < .001), as well as in patients with thyrotoxicosis (P = .027) compared with controls. Age was an effect modifier in hypothyroid patients.ConclusionThis study shows that both overt and subclinical hypothyroidism as well as thyrotoxicosis were associated with an increase of aortic stiffness. The impact of treatment of these conditions on aortic stiffness should be assessed in clinical trials.

Challenges in the Management of Atrial Fibrillation With Subclinical Hyperthyroidism.

Subclinical thyroid disorders have a high prevalence among older individuals and women. Subclinical hypothyroidism is diagnosed by elevated serum levels of thyroid-stimulating hormone (TSH) with thyroxine levels within the reference range, and subclinical hyperthyroidism is diagnosed by low TSH in conjunction with thyroxine and triiodothyronine levels within reference ranges. Atrial fibrillation is the most commonly diagnosed cardiac arrhythmia and has been associated with an increased risk of mortality, heart failure, stroke, and depression. Mechanistic data from animal and human physiology studies as well as observational data in humans support an association of subclinical hyperthyroidism with atrial fibrillation. Guidelines recommend the measurement of TSH in the evaluation of new-onset atrial fibrillation. All patients with overt hyperthyroidism should be treated, and treatment of subclinical hyperthyroidism should be considered in patients older than 65 years with TSH < 0.4 mlU/L, or in younger patients with TSH < 0.1 mlU/L. Guidelines also recommend screening for AF in patients with known hyperthyroidism. Wearable devices that measure the heart electrical activity continuously may be a novel strategy to detect atrial fibrillation in patients at risk. In this review, we explore the interplay between thyroid hormones and atrial fibrillation, management controversies in subclinical hyperthyroidism, and potential strategies to improve the management of atrial fibrillation in patients with subclinical hyperthyroidism.

The Study of Prevalence and Pattern of Thyroid Disorder in Pregnant Women: A Prospective Study

BackgroundThe most frequent thyroid disorder in pregnancy is maternal hypothyroidism. The geographical variation in the prevalence of hypothyroidism during pregnancy is very wide and ranges from 2.5% to 11%. The prevalence of hypothyroidism is more in Asian countries as compared to western countries. Thus, this study was conducted to find out the prevalence of thyroid disorder in pregnancy at our center.MethodsThe present study was conducted in the Department of Physiology in collaboration with the Department of Obstetrics & Gynecology, Index Medical College, Hospital and Research Center, Indore, MP, India over a period of one and a half years from October 2018 to March 2020. It was a cross-sectional study including 865 pregnant women. The patients' demographic profile was noted in all cases. A detailed history and thorough examination were done in all cases. Serum thyroid-stimulating hormone (TSH), Free T3, and Free T4 (FT3 and FT4) were done along with routine blood investigations as per The Federation of Obstetric and Gynaecological Societies of India-Indian College of Obstetricians and Gynaecologists (FOGSI-ICOG) good clinical practice recommendation.ResultsIn this study, the prevalence of thyroid dysfunction was 10.4%. Of these 90 patients with thyroid dysfunction, subclinical and overt hypothyroidism was found in 5.50% and 0.92%, respectively, whereas subclinical and overt hyperthyroidism was observed in 3.12% and 0.81% pregnant females, respectively. A significant association was found between thyroid dysfunction and maternal age, BMI, parity, and education.ConclusionsThe prevalence of thyroid dysfunction was 10.4% in this study. Hypothyroidism was more common than hyperthyroidism and subclinical thyroid disorders were more common than overt thyroid disorders in pregnancy. Therefore, we should include thyroid function tests with other routine investigations during pregnancy to detect thyroid dysfunction.

THYROID DISORDERS IN PATIENTS WITH MELASMA

Background and objectives: Melasma, a common pigmentary disorder is major cosmetic concernamong patients. The aim of our study was to determine the frequency of thyroid disorders in melasma cases. Methodology: Thisobservational study was conducted at RIHS DermatologyDepartment Islamabad from 20thFeb–20thMay 2021. Diagnosed cases of melasma (&gt;18 years) were selected via consecutive sampling technique.Themedically/surgically treated cases of thyroid, melasma secondary to other dermatosis, organ failure, Addisons disease, pregnancy and subclinical thyroid disorders were excluded. After detailed clinical evaluation, thyroid status documented on the basis of thyroid function tests. Data analysed by SPSS with significant p-value&lt;0.05. Results: Amongst 150 melasma cases 117(78%) females and 33(22%) males, mean age was 35.45+9.68 years. 36(24%) were euthyroid, 109(72.7%) hypothyroid and 5(3.3%) hyperthyroid. Mean TSH was 1.82+18.64 mIU/L. 75(50%) had epidermal, 38(25.3%) dermal and 37(24.7%) mixed melasma, hypothyroidism frequent in all three types. Dermal melasma frequent in 41-50 years, epidermal in 20-30 years and mixed in 31-40 years. Thyroid status had significant association with age group, hypothyroidism more common in 41-50 years and Euthyroid in &lt;30 years. Obesity observed in 55(36.7%) having significant association with hypothyroidism. Mandibular melasma observed in 88%, malar 77.3%, centro-facial18.7% and neck melasma 9.3%. Conclusion: Thyroid disorders, particularly hypothyroidism is frequent among melasma cases.Authors recommend to screen all melasma cases regardless of age or gender for thyroid disorders, in particular obese cases. The diagnosis and management of thyroid disease in melasma cases may improve quality of life, prevent thyroid related complications and improve outcome of melasma treatment.

Overutilization and Underutilization of Thyroid Function Tests are Major Causes of Diagnostic Errors in Pregnant Women.

The failure to order the correct diagnostic test at the right time is one of the major contributing factors of diagnostic error. Excessive testing can lead to added economic burden and addressing underutilization is precarious as clinicians often fail to order the tests that would improve diagnosis, prognosis, and management. A retrospective analysis of errors in test orders of thyroid function testing (TFT) in 321 pregnant women suspected of clinical and subclinical thyroid disorders was performed. Test selection was evaluated, and determinations were made about the extent of overutilization and underutilization of TFTs in reviewing each individual patient case by a Doctorate in Clinical Laboratory Science (DCLS) scholar. About 77% (247 cases) of the cases were found to have errors associated with test ordering for TFT. Of the cases reviewed, 18% cases were associated with overutilization, 53% of the cases were associated with underutilization, and 7% were associated with both (overutilization and underutilization). The annual cost burden because of ordering unnecessary tests was estimated to be approximately $13,000. The cost burden from errors resulting from not ordering a test would be of much greater magnitude but was difficult to estimate because underutilization has a ripple effect and may cause prolonged hospital stays, unnecessary medical bills, and delayed/ missed diagnosis leading to poor outcomes for patients. This study evaluated whether proper utilization of TFT were made at maternal health clinic locations of a large academic medical center in pregnant women to diagnose thyroid disorder and reported the issue of wastage of resources in the clinical laboratory. The study findings show significant errors in ordering of TFT for pregnant women in more than 75% of the cases that was based on evidence-based review of patient cases.

To evaluate the presence of subclinical thyroid disorder in type 2 diabetes mellitus

Objectives: Our objective is to determine the prevalence of subclinical thyroid disorders in patients with type 2 diabetes mellitus (T2DM) and to analyze the clinical and metabolic profile of patients with this dual endocrine disorder. Methods and Results: Sixty consecutive type 2 diabetic patients without clinical manifestations of thyroid disorders were screened for SCH and subclinical hyperthyroidism using serum free T 3, free T 4 and thyroid stimulating hormone (TSH) levels. Individuals of subclinical thyroid disease were further screened for thyroperoxidase (TPO) antibodies. SCH was detected in 13% of type 2 diabetic patients and none had subclinical hyperthyroidism in our study. SCH was common among females with type 2 diabetes (84.6%). Elevated TPO antibody levels were present in 84.6% SCH patients. Diabetic retinopathy among SCH patients showed significant association with higher serum TSH levels. Left ventricular diastolic dysfunction was present in 30.8% of SCH patients. Conclusion: SCH is common among type 2 diabetic patients, especially in females. It is most commonly secondary to autoimmune thyroid disease. Microvascular complications are commonly observed in this group of patients with dual endocrinal disorder and treating physician should be aware of the impact and should routinely screen SCH to prevent complications.

Abstract P490: Subclinical Thyroid Disorders and Triglyceride-rich Lipoprotein Particles Concentration. ELSA-Brasil Cohort

Background: Subclinical thyroid disorders have been associated with atherosclerosis and increased cardiovascular risk. Subclinical hypothyroidism is associated with higher levels of total cholesterol and Low-density lipoprotein cholesterol as well as high levels of triglycerides and low levels of high-density lipoprotein cholesterol. Triglyceride-rich Lipoprotein Particles concentration (TRLP) have recently emerged as a causal factor for atherogenesis. Aim: To evaluate the relationship between Subclinical Hypothyroidism and Subclinical Hyperthyroidism and Triglyceride-rich Lipoprotein Particles. Methods: Participants from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) were classified according to the baseline thyroid function as Subclinical Hypothyroidism, Euthyroidism, and Subclinical Hyperthyroidism. Conventional lipid concentrations (total, HDL cholesterol, and triglycerides were determined by a nonprecipitated colorimetric method. The TRLP subfractions were analyzed through Nuclear Magnetic Resonance spectroscopy. To examine the association between TRLP subfractions and thyroid function, we conducted a multivariate linear regression model adjusted for demographic characteristics (race, gender, and educational level), body-mass index, diabetes, smoking status, and alcoholic beverages intake. Results: Of 3,550 individuals free of cardiovascular or thyroid diseases (54%, women; median age 51 years; 51% White, and 53% with at least college education) 92%of them were euthyroid, 6.8% had subclinical hypothyroidism, and 1.2% had subclinical hyperthyroidism. No differences were observed concern the levels of total, HDL, and LDL-cholesterol, but triglycerides were higher for people with Subclinical Hypothyroidism. After adjustment by the covariates described above and using subjects with normal thyroid function as the reference group, for people with Subclinical hypothyroidism a difference of means ( and 95% Confidence Interval) for Total TRLP levels (in ng/L) obtained was 0.06 (-0.00 to 0.13), and for the TRLP subfractions elevated for Very-Small [0.16 (0.02 to 0.28)] and Very-Large [0.21 (0.05 to 0.36)], and similar values for Small [-0.01 (-0.13 to 0.12)]; Medium [0.05 (-0.08 to 0.17)] and Large [0.16 (-0.06 to 0.38)] subfractions. In Subclinical Hyperthyroidism, there was a reduction in Total TRLP (-0.24 (-0.40 - -0.08)), seemingly driven by reduced Very Small-TRLP (0.23 (-0.11 - 0.57). Conclusion: This study suggests that subclinical hypothyroidism is associated with high levels of Very-Small and Very-Large TRLP, which are related to an unfavorable atherogenic profile. Subclinical Hyperthyroidism is associated with low concentrations of Very-Small TRLP.

Thyroid Dysfunction and Atherosclerosis: A Systematic Review.

Thyroid dysfunction, both hypo- and hyperthyroidism, has been associated with cardiovascular disease. The aim of this study was to evaluate the association between thyroid dysfunction and atherosclerosis measured mostly by carotid intima-media thickness, as well as discuss whether L-T4 replacement is able to reverse or slow down the progression of atherosclerosis. The review was conducted according the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. We performed on PubMed a literature search from May 2004 to January 2020, using the search terms 'subclinical hypothyroidism' or 'thyroid disorders' and 'carotid artery', 'carotid intima-media thickness (IMT)', 'levothyroxine', and 'atherosclerosis'. Twenty-six studies were eligible and included in the analysis. Overall, the studies encompassed a total of 36.434 patients included in this review. Most studies indicated a proportional correlation between IMT and thyroid dysfunction. Levothyroxine (L-T4) replacement led to significant decrease of IMT after 1 year in most studies. Most studies have concluded that thyroid dysfunction is associated with arterial wall remodeling and, thus, with increased cardiovascular risk. However, the exact mechanistic background of pathological structural changes in the arterial wall is still unsettled. Large randomized controlled studies are required to definitively address the extent to which T4 replacement therapy might benefit patients with subclinical thyroid disorders.

Schilddrüse und Schwangerschaft

Pregnancy has a profound impact on the thyroid gland and its function. This has to be considered in the assessment of thyroid function tests on the basis of trimester-specific reference intervals during pregnancy and in the decision making when to start therapy.The adverse impact of overt thyroid disorders in pregnancy is well understood, while the relevance of subclinical thyroid disorders and presence of thyroid antibodies remains a bit controversial. In euthyroid pregnant women with positive thyroid antibodies, levothyroxine (LT4) therapy may be discussed individually in the case of recurrent abortions. Furthermore, the risk of adverse pregnancy outcomes seems to be increased in the presence of both thyroid-stimulating hormone (TSH)-elevation and positive thyroid antibodies. Therefore, in case of subclinical hypothyroidism, taking in consideration the thyroid peroxidase antibody (TPO-Ab)-status individual decision-making and liberal initiation of LT4 therapy is recommended. In contrast, overt hypothyroidism is a strong indication for LT4 administration, aiming at rapid achievement of euthyroidism.The most common cause of hyperthyroidism is transient gestational thyrotoxicosis mediated by human chorionic gonadotropin (hCG), which leads to a reduction or suppression of TSH in the first trimester that does not require antithyroid medication. In other causes of overt hyperthyroidism antithyroid drugs (propylthiouracil or thionamides) need to be considered carefully and require interdisciplinary management.The presented recommendations are based on the current guideline of the American Thyroid Association (ATA) and the European Thyroid Association (ETA) as well as recently published literature.

Thyroid dysfunction and electrocardiographic changes in subjects without arrhythmias: a cross-sectional study of primary healthcare subjects from Copenhagen

ObjectiveThe objective of the present study was to investigate associations of both overt and subclinical thyroid dysfunction with common ECG parameters in a large primary healthcare population.DesignCross-sectional study.Setting and participantsThe...

Abstract P029: Inflammation Measured by Glyc-A as a Mediating Factor Between Subclinical Thyroid and Cardiovascular Diseases. The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Introduction: An auto-immune process strongly determines subclinical thyroid disorders generating a high grade of inflammation. However, the evidence from epidemiologic studies of the association between subclinical thyroid disorders with coronary heart disease has not been reported as mediated or moderated by a traditional inflammatory marker such as the high-sensitivity C-Reactive Protein. Recently, another inflammatory marker that reflects protein glycosylation in acute-phase reactant proteins - GlycA was associated with coronary heart disease events. Hypothesis: The association of GlycA, a more comprehensive biomarker of inflammation, with subclinical hypothyroidism, and subclinical hyperthyroidism, should explain some mechanisms of the association subclinical thyroid disorders and coronary heart disease. Methods: We tested this hypothesis among 5060 men and women aged 35 to 74 years-old enrolled in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) at baseline. Subclinical thyroid disorders were defined as thyroid-stimulating hormone (TSH) &gt;4 IU/ml (subclinical hypothyroidism) and TSH &lt;0.4 IU/ml (subclinical hyperthyroidism) with normal free-thyroxine levels. The variable of exposure was GlycA measured in serum by proton nuclear magnetic resonance (1H NMR) spectroscopy at (LabCorp, Raleigh, NC). We excluded participants who reported previous cardiovascular disease, use of lipid-lowering agents or drugs that interfere with thyroid function. The cross-sectional relationship between GlycA and subclinical hyperthyroidism and subclinical thyroid was evaluated separately by linear regression models using the category of the subjects with euthyroidism as the reference. Both crude unadjusted and adjusted (age, sex, race, education, smoking, alcohol use, physical activity body-mass index, hypertension, diabetes, smoking, alcohol use, and physical activity data are presented Results: After exclusions, we analyzed 47 individuals with subclinical hyperthyroidism (mean age 53.1 (±9.4) years; 61.7% women), 258 with subclinical hypothyroidism (mean age 52.3 (±8.9); 58.1% of women) and 3,642 participants with normal thyroid function (mean age: 50.1 (±8.6); 52% of women). Crude linear regression models showed no significant association between GlycA and subclinical hyperthyroidism (Beta-coefficient [B], 15.77; P = 0.10) or subclinical hypothyroidism (B, 3.60; P=0.39). Results remained nonsignificant after multivariate adjustment for subclinical hyperthyroidism (B, 12.96; P=0.15) and subclinical hypothyroidism (B, 0.44; (P=0.91). Conclusions: There is no association between subclinical thyroid disorders and GlycA. Other presumptive inflammatory pathways should be contemplated in further studies addressing the link between subclinical thyroid disorders and coronary heart disease.