Consenso brasileiro para a abordagem clínica e tratamento do hipotireoidismo subclínico em adultos: recomendações do Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia

Use of transient elastography for hepatic steatosis and fibrosis evaluation in patients with subclinical hypothyroidism

OBJECTIVE

To evaluate the association between subclinical hypothyroidism and hepatic steatosis and fibrosis using the noninvasive diagnostic methods transient hepatic elastography (TE) and controlled attenuation parameter (CAP) in patients with subclinical hypothyroidism.

SUBJECTS AND METHODS

This was a cross-sectional study including women with confirmed spontaneous subclinical hypothyroidism and an age- and body mass index (BMI)-matched control group without thyroid disease or circulating antithyroperoxidase (anti-TPO) antibodies. Exclusion criteria were age > 65 years, thyroid-stimulating hormone (TSH) > 10.0 mIUI/L, BMI ≥ 35 kg/m2, diabetes, or other chronic liver diseases. Liver stiffness was classified according to TE values (in kPa) and ranged from absence of fibrosis (F0) to advanced fibrosis (F3). Hepatic steatosis was classified according to CAP values (in dB/m) and ranged from low-grade (S1) to advanced (S3) steatosis.

RESULTS

Of 68 women enrolled, 27 were included in the subclinical hypothyroidism group and 41 in the control group. Advanced steatosis (S3) was more frequent in the subclinical hypothyroidism group (25.9% versus 7.3%, respectively, p = 0.034). Circulating anti-TPO was an independent factor associated with advanced steatosis (odds ratio 9.5, 95% confidence interval 1.3-68.3). In multiple linear regression analysis, TE values (which evaluated fibrosis) correlated negatively with free thyroxine levels.

CONCLUSION

The results of this study strengthen the hypothesis that hepatic steatosis is associated with autoimmune (positive anti-TPO) subclinical hypothyroidism, independently from BMI. However, subclinical hypothyroidism alone does not appear to be associated with a significantly increased risk of hepatic fibrosis.

The different outcomes in the elderly with subclinical hypothyroidism diagnosed by age-specific and non-age-specific TSH reference intervals: a prospectively observational study protocol

Introduction

Subclinical hypothyroidism (SCH) is a common endocrine disorder characterized by elevated thyroid-stimulating hormone (TSH) levels and normal free thyroxine (FT4) levels. The overdiagnosis and overtreatment of SCH in elderly patients have become concerns as TSH levels naturally increase with age. Studies have shown that many elderly patients with SCH can recover without treatment, and the administration of levothyroxine (L-T4) does not improve their prognosis. Therefore, It is necessary to establish age-specific reference ranges for TSH in elderly individuals to aid in clinical decision-making and prevent overdiagnosis.

Methods

This is a multicenter prospective study that focuses on Chinese elderly patients with SCH who have TSH levels below 10 mU/L. After obtaining the informed consent of the patients, their initial diagnosis information will be registered, and they will be asked to fill out questionnaires such as the Montreal Cognitive Assessment-Basic (MoCA-B), Hamilton Depression Scale (HAMD), Hypothyroidism Symptom Questionnaire (SRQ), frail scale(FRAIL), fatigue scale, and EQ-5D. In addition, thyroid function tests, blood lipid analysis, carotid artery ultrasound, and thyroid ultrasound examinations will be conducted. Patients will also be grouped according to FT4 levels, the changes in FT4 and its relationship with TSH can also be described. For patients over 80 years old, a decrease in FT4 will be used as an endpoint event, while for patients between 60-80 years old, TSH levels greater than or equal to 10mIU/L or a decline in FT4 will be used as the endpoint event. The TSH reference intervals of the general and elderly populations will be used to calculate medical costs associated with multiple follow-ups of patients, and a social-economic analysis will also be conducted.

Discussion

This study will prospectively observe elderly patients with SCH who are screened using both age-specific and non-age-specific TSH reference ranges for the elderly population. We will compare the results of elderly patients diagnosed with SCH using different reference ranges and analyze their association with FT4 to identify meaningful SCH patients and reduce over diagnosis and over treatment of elderly SCH.

Ethics

The Medical Science Research Ethics Committee of the First Affiliated Hospital of China Medical University approved this study (ID: AF-SOP-07-1.1-01). The results will be published in an open-access journal.

Clinical trial registration

https://www.chictr.org.cn/, identifier ChiCTR2300070831.

Reference intervals for serum TSH concentrations of healthy children from the Central Region of Brazil

Objective

The objective of this study was to determine the serum thyroid-stimulating hormone (TSH) concentration reference intervals (RIs) of healthy children aged 1 to 10 years of both sexes, living in the Central Region of Brazil.

Subjects and methods

1,735 children [869 (50.1%) female; 866 (49.9%) male] enrolled in the morning shift of 47 pre- and 83 public elementary schools in the municipality of Cuiabá, Mato Grosso, were studied by gathering anthropometric and social data and their medical history. A blood sample was collected from each child to determine the TSH concentration using the electrochemiluminescence method on a Cobas® 6000 modular analyzer (Analyzer series, Roche Diagnostics).

Results

The RIs were determined using the 2.5 and 97.5 percentile and the mean ± 2 standard deviations methods. After identifying the homoscedastic groups by age and sex, outliers higher or lower than three standard deviations were excluded. The distribution of serum TSH concentrations showed no significant age or sex differences. Based on the percentile method, TSH RI ranged from 0.93 to 5.86 μIU/mL. Based on the mean ± 2 standard deviations, TSH RI ranged from 0.30 to 5.29 μIU/mL.

Conclusion

The normal serum TSH concentration of the Brazilian children evaluated in this study differ from those of populations from other countries. Other regional population studies may validate the RIs found in this study and enable its safer use in pediatric clinical practice.

Approach to adult patients with primary hypothyroidism in some special situations: a position statement from the Thyroid Department of the Brazilian Society of Endocrinology and Metabolism (SBEM)

Primary hypothyroidism is a common disorder in clinical practice. The management of most cases of hypothyroidism is usually straightforward, but the best approach in some special situations may raise questions among physicians. This position statement was prepared by experts from the Brazilian Society of Endocrinology and Metabolism to guide the management of three special situations, namely, hypothyroidism in the elderly, subclinical hypothyroidism in patients with heart disease, and difficult-to-control hypothyroidism. The authors prepared the present statement after conducting a search on the databases MEDLINE/PubMed, LILACS, and SciELO and selecting articles with the best evidence quality addressing the selected situations. The statement presents information about the current approach to patients in these special situations.

Management of Hypothyroidism and Hypothyroxinemia in Pregnancy

OBJECTIVE

To review the diagnosis and management of hypothyroidism in pregnancy, preconception, and the postpartum period.

METHODS

Literature review of English-language papers published between 1982 and 2022, focusing on the most recent literature.

RESULTS

During pregnancy, thyroid function laboratory tests need to be interpreted with regard to gestational age. Overt hypothyroidism, regardless of the TSH level, should always be promptly treated when it is diagnosed preconception or during pregnancy or lactation. Most women with preexisting treated hypothyroidism will require an increase in levothyroxine dosing to maintain euthyroidism during gestation. levothyroxine-treated pregnant patients need close monitoring with serum thyroid stimulating hormone (TSH) to avoid or- or under treatment. There is no consensus about whether to initiate levothyroxine in women with mild forms of gestational thyroid hypofunction. However, in light of current evidence it is reasonable to treat subclinically hypothyroid women with levothyroxine, particularly if the TSH is >10 mIU/L or the thyroperoxidase antibody is positive. Women who are not treated need to be followed to ensure that treatment is initiated promptly if thyroid failure progresses. Additional studies are needed to better understand the effects of the initiation of levothyroxine in early gestation in subclinically hypothyroid and hypothyroxinemic women and to determine optimal strategies for thyroid function screening in preconception and pregnancy.

CONCLUSION

The diagnosis and management of hypothyroidism in the peripregnancy period present specific challenges. In making management decisions, it is essential to weigh the risks and benefits of treatments not just for the mother but also for the fetus.

Effect of Levothyroxine on Older Patients With Subclinical Hypothyroidism: A Systematic Review and Meta-Analysis

BACKGROUND

Subclinical hypothyroidism (SCH) is usually treated with levothyroxine, but there is controversy as to whether SCH should be treated, especially for older patients. The aim of the systematic review and meta-analysis was to evaluate whether levothyroxine has a beneficial or harmful effect on older patients with SCH.

METHODS

Databases including PubMed, Embase, Cochrane Library, Web of Science, Wanfang, Weipu and China National Knowledge Infrastructure were searched from inception until December 21, 2021. Subjects must be diagnosed with SCH, and older than or equal to 60 years of age. Interventions should be thyroid hormone therapy (e.g. levothyroxine). The literature was independently screened by 2 researchers. Statistical analysis was performed using RevMan5.3 software.

RESULTS

A total of 13 articles were included. Meta-analysis results showed that in older SCH patients, levothyroxine can significantly reduce cholesterol (TC) (p < 0.00001), triglyceride (TG) (p < 0.00001), low-density lipoprotein cholesterol (LDL-C) (p = 0.03) and apolipoprotein B (ApoB) (p < 0.00001). In addition, levothyroxine had no significant effect on bone mineral density, fatigue, hypothyroidism symptoms, quality of life, BMI, cognitive function, depression, blood pressure, etc. in older SCH patients, and also did not significantly increase the incidence of adverse events.

CONCLUSIONS

Among older SCH patients, levothyroxine treatment may reduce TC, TG, LDL-C, and ApoB.

IgG Subclass Analysis in Patients with Chagas Disease 4 Years After Benznidazole Treatment

BACKGROUND

In humans, Trypanosoma cruzi infection is controlled by a complex immune response. Immunoglobulin G (IgG) is important for opsonizing blood trypomastigotes, activating the classic complement pathway, and reducing parasitemia. The trypanocidal activity of benznidazole is recognized, but its effects on the prevention and progression of Chagas disease is not well understood OBJECTIVE: We aimed to evaluate the levels of total IgG and cross-specific IgG subclasses in patients with chronic Chagas disease of different clinical forms before and after 4 years of benznidazole treatment.

METHODS

Eight individuals with the indeterminate form and nine with the cardiac form who completed the treatment protocol were evaluated. The levels of total IgG and IgG1, IgG2, IgG3, and IgG4 isotypes were quantified in the serum of each individual using the fluorescent immunosorbent assay. The results are expressed as relative fluorescence unit.

RESULTS

Patients with chronic Chagas disease presented decreased levels of total IgG at 48 months after benznidazole treatment. Increased IgG1 and decreased IgG3 levels were observed in patients with the cardiac form and those with exacerbated clinical forms. In addition, a decrease in the IgG3/IgG1 ratio was observed in individuals with the cardiac form of Chagas disease.

CONCLUSIONS

Benznidazole administration in the chronic phase differentially changes IgG subclasses in patients with cardiac and indeterminate forms, and monitoring the IgG3 level may indicate the possible prognosis to the cardiac form or worsening of the already established clinical form.

A practical contemporary approach to decision-making on subclinical hypothyroidism

Subclinical hypothyroidism (Shypo) is an increasingly frequent condition in common medical practice. Its diagnosis continues to pose a challenge since a series of non-thyroidal and temporary conditions can elevate serum TSH levels. In addition, the consequences of Shypo are still up for debate. Although detrimental cardiovascular effects have been consistently demonstrated in the young, they are less evident in older adults (65-79 years), and even more so in the oldest old (≥80 years). In the absence of evidence of any benefits of treating Shypo in patients' clinical manifestations and unfavorable outcomes, the most effective decision-making approach should include a thorough investigation of the patient's condition integrating all relevant clinical data, such as TSH levels, age, quality of life, comorbidities, cardiovascular risk, safety, and personal preferences. The decision-making process needs to take into account the risk of levothyroxine overtreatment and the resulting adverse consequences, such as reduction of bone mineral density, heart failure, and atrial fibrillation. Hence, current evidence suggests that individuals with TSH > 10 mU/L, who test positive for TPO Ab or are symptomatic may benefit from levothyroxine treatment. However, a more cautious and conservative approach is required in older (≥65 years of age), and oldest-old (≥80 years) patients, particularly those with frailty, in which the risk of treatment can outweigh potential benefits. The latter may benefit from a wait-and-see approach.

Laparoscopic Sleeve Gastrectomy has A Positive Impact on Subclinical Hypothyroidism Among Obese Patients: A Prospective Study

BACKGROUND

The effect of bariatric surgery on postoperative thyroid function remains incompletely understood. In this study, we aimed to evaluate the changes in thyroid functions after gastric sleeve operation for morbidly obese Egyptian patients.

METHODS

This was a prospective study that recruited 128 patients who underwent sleeve gastrectomy through the period from December 2016 to April 2020. We measured thyroid-stimulating hormone (TSH), free thyroxin (FT4), and free triiodothyronine. Subclinical hypothyroidism was defined by a TSH level > 4.5 mIU/L but a normal FT4 level. All patients were followed for 12 months after the procedure.

RESULTS

Preoperatively, 30 (23.4%) patients had subclinical hypothyroidism. The prevalence of subclinical hypothyroidism decreased significantly to reach 7.8% at the end of follow-up (p < 0.001). None of the patients developed de novo hypothyroidism at the end of follow-up. Patients with subclinical hypothyroidism were more likely to be females (p = 0.037) and had significantly higher waist circumference (p < 0.001), DBP (p = 0.02), serum cholesterol (p < 0.001), and serum triglyceride (p < 0.001). However, patients with subclinical hypothyroidism at the end of follow-up had significantly higher BMI at the end of the sixth month (p = 0.048). Similarly, patients with subclinical hypothyroidism at the end of follow-up had significantly higher serum cholesterol (p = 0.002), LDL, (p = 0.038), and serum triglyceride (p < 0.001) at the end of the sixth months of follow-up. A similar trend was noted at the end of the 12th month. The preoperative value of serum TSH correlated significantly with serum cholesterol and triglyceride levels.

CONCLUSION

The positive effect of the LSG procedure on the hypothyroid bariatric population, including enhanced thyroid function, was demonstrated.

Detection of Alterations in the Gut Microbiota and Intestinal Permeability in Patients With Hashimoto Thyroiditis

Hashimoto thyroiditis (HT) is the most common autoimmune disease worldwide, characterized by chronic inflammation and circulating autoantibodies against thyroid peroxidase and thyroglobulin. Patients require hormone replacement with oral levothyroxine, and if untreated, they can develop serious adverse health effects and ultimately death. There is a lot of evidence that the intestinal dysbiosis, bacterial overgrowth, and increased intestinal permeability favor the HT development, and a thyroid–gut axis has been proposed, which seems to impact our entire metabolism. Here, we evaluated alterations in the gut microbiota in Brazilian patients with HT and correlated this data with dietary habits, clinical data, and systemic cytokines and zonulin concentrations. Stool samples from 40 patients with HT and 53 controls were analyzed using real-time PCR, the serum cytokine levels were evaluated by flow cytometry, zonulin concentrations by ELISA, and the dietary habits were recorded by a food frequency questionnaire. We observed a significant increase (p < 0.05) in the Bacteroides species and a decrease in Bifidobacterium in samples of patients with HT. In addition, Lactobacillus species were higher in patients without thyroid hormone replacement, compared with those who use oral levothyroxine. Regarding dietary habits, we demonstrated that there are significant differences in the consumption of vegetables, fruits, animal-derived proteins, dairy products, saturated fats, and carbohydrates between patients and control group, and an inverse correlation between animal-derived protein and Bacteroides genus was detected. The microbiota modulation by diet directly influences the inflammatory profile due to the generated microbiota metabolites and their direct or indirect action on immune cells in the gut mucosa. Although there are no differences in systemic cytokines in our patients with HT, we detected increased zonulin concentrations, suggesting a leaky gut in patients with HT. These findings could help understand the development and progression of HT, while further investigations to clarify the underlying mechanisms of the diet–microbiota–immune system axis are still needed.

Universal screening for thyroid disease during pregnancy should be performed

Thyroid disease can significantly impact the pregnant woman and her child. Human and animal studies have firmly linked overt hypothyroidism and overt hyperthyroidism to miscarriage, preterm delivery and other adverse pregnancy outcomes. Overt hypothyroidism and overt hyperthyroidism affect 1% of all pregnancies. Treatment is widely available, and if detected early, results in decreased rates of adverse outcomes. Universal screening for thyroid disease in pregnancy can identify patients with thyroid disease requiring treatment, and ultimately decrease rates of complications. Universal screening is cost-effective compared to the currently accepted practice of targeted screening and may even be cost-saving in some healthcare systems. Targeted screening, which is recommended by most professional associations, fails to detect a large proportion of pregnant women with thyroid disease. In fact, an increasing number of providers are performing universal screening for thyroid disease in pregnancy, contrary to society guidelines. Limited evidence concerning the impact of untreated and treated subclinical disease and thyroid autoimmunity has distracted from the core rationale for universal screening - the beneficial impact of detecting and treating overt thyroid disease. Evidence supporting universal screening for overt disease stands independently from that of subclinical and autoimmune disease. The time to initiate universal screening is now.

Clinical and subclinical maternal hypothyroidism and their effects on neurodevelopment, behavior and cognition

Clinical and subclinical hypothyroidism are the most common hormonal dysfunctions during pregnancy. Insufficient maternal thyroid hormones (THs) in the early stages of pregnancy can lead to severe impairments in the development of the central nervous system because THs are critical to central nervous system development. In the fetus and after birth, THs participate in neurogenic processes, cell differentiation, neuronal activation, axonal growth, dendritic arborization, synaptogenesis and myelination. Although treatment is simple and effective, approximately 30% of pregnant women in Brazil with access to prenatal care have their first consultation after the first trimester of pregnancy, and any delay in diagnosis and resulting treatment delay may lead to cognitive impairment in children. This review summarizes the effects of clinical and subclinical hypothyroidism on fetal neurodevelopment, behavior and cognition in humans and rodents. Arch Endocrinol Metab. 2020;64(1):89-95.

To Treat or Not to Treat Subclinical Hypothyroidism, What Is the Evidence?

OBJECTIVE

levothyroxine prescriptions have increased remarkably during the last decade, and it is most likely to be prescribed in subclinical hypothyroidism. The aim of this review was to present data on when levothyroxine treatment should be initiated, and the effects of treatment in subclinical hypothyroidism on symptoms such as weight, quality of life, vitality, cognition, and cardiovascular disease. We also discuss evidence for different thyroid-hormone medications. In addition, the option to withhold medication when there is uncertain diagnosis or lack of clinical improvement is discussed.

METHODS

a literature search in PubMed on the term "treatment of subclinical hypothyroidism" in combination with "quality of life", "weight", "cognition", and "cerebrovascular disease".

RESULTS

current research supports that levothyroxine should be initiated in patients with a thyroid stimulating hormone (TSH) >10 mIU/L. Treatment for hypothyroidism is becoming more frequent. Symptoms related to vitality, weight, and quality of life in subclinical disease often persist with levothyroxine treatment, and other causes should be explored. Patients with cardiovascular-risk factors may benefit from treatment, especially younger patients. Caution is necessary when treating elderly subjects with levothyroxine.

CONCLUSION

lifelong treatment with levothyroxine should normally only be considered in manifest hypothyroidism. However, in subclinical hypothyroidism with a TSH >10 mIU/L, therapy is indicated. In milder subclinical forms, a wait-and-see strategy is advocated to see if normalization occurs. Subgroups with cardiovascular risk and subclinical hypothyroidism may benefit from levothyroxine therapy.

Thyroid function before and after Roux-en-Y gastric bypass: an observational study

BACKGROUND

Population studies have shown a positive association between thyroid-stimulating hormone (TSH) and body mass index. Recent studies have shown a significant increase in the prevalence of subclinical hypothyroidism (SCH) in obesity. Weight reduction after Roux-en-Y gastric bypass (RYGB) seems to significantly decrease TSH levels.

OBJECTIVES

The purpose of this study was to evaluate the prevalence of SCH in obese patients (class II and III) and to observe the behavior of thyroid hormones (TSH, hormone triiodothyronine, thyroxine, free thyroxine) with significant weight loss after RYGB.

SETTING

Hospital Nossa Senhora das Graças, Curitiba, Paraná, Brazil.

METHODS

We retrospectively reviewed the medical records of 215 obese patients who underwent RYGB between 2005 and 2012 with a follow-up of at least 2 years. The study was observational and descriptive. The selected times for clinical and laboratory evaluations were preoperative, 3, 6, 12, and 24 months after the procedure. Association, correlation, and variance analyses were performed.

RESULTS

The prevalence of SCH preoperatively was 9.3%. SCH was corrected in 89.5% of patients 12 months after RYGB. We did not find an association between TSH and BMI (r = .002, P = .971). There was a positive impact of bariatric surgery on all metabolic variables. We showed that serum TSH level had no positive correlation with the presence or absence of metabolic syndrome.

CONCLUSIONS

Weight loss after bariatric surgery leads to normalization of TSH levels in most patients and none developed overt hypothyroidism. Obese patients with SCH should not be treated with thyroid hormone replacement. Serial monitoring of thyroid function after obesity therapy seems to be a reasonable approach.

Reference intervals in the diagnosis of thyroid dysfunction: treating patients not numbers

Although assigning a diagnosis of thyroid dysfunction appears quite simple, this is often not the case. Issues that make it unclear whether thyroid function is normal include transient changes in thyroid parameters, inter-individual and intra-individual differences in thyroid parameters, age-related differences, and ethnic variations. In addition, a statistically calculated distribution of thyroid analytes does not necessarily coincide with intervals or cutoffs that have predictive value for beneficial or adverse health outcomes. Based on current clincial trial data, it is unclear which individuals with mild thyroid-stimulating hormone elevations will benefit from levothyroxine treatment. For example, only a small number of patients with thyroid-stimulating hormone values of more than 10 mIU/L have been studied in a randomised manner. Even if therapy is initiated for abnormal thyroid function, not all treated individuals are maintained at the desired treatment target, and therefore might still be at risk. The consequence of this is that each patient's thyroid function needs to be assessed on an individual basis with the entire clinical picture in mind. Monitoring also needs to be vigilant, and the targets for treatment reassessed continually.

Selective screening for thyroid dysfunction in pregnant women: How often do low-risk women cease to be treated following the new guidelines of the American Thyroid Association?

OBJECTIVE

Universal screening for thyroid dysfunction in pregnant women is not recommended by the American Thyroid Association (ATA) or the American Association of Clinical Endocrinologists (AACE). This study evaluated the frequency of pregnant women that would have an indication for levothyroxine (L-T4) according to the new ATA/AACE guidelines among low-risk women without an indication for screening with TSH.

SUBJECTS AND METHODS

The sample consisted of 412 pregnant women ranging in age from 18 to 30 years. These women were considered to be at low risk for thyroid dysfunction according to ATA/AACE and would not be candidates for screening with TSH. Anti-thyroid peroxidase antibodies (TPOAb) and TSH were measured. Women who had TSH > 2.5 mIU/L or TPOAb in the first trimester were submitted to subsequent evaluations in the second and third trimester.

RESULTS

In the first trimester, none of the pregnant women would have L-T4 therapy "recommended" and treatment would be "considered" in only two. In the second trimester, pregnant women with positive TPOAb or TSH > 2.5 mIU/L in the first trimester (n = 30) were reevaluated. L-T4 treatment would be "recommended" in only one woman and would be "considered" in two others. The 28 women that were not treated in the second trimester were reevaluated in the third trimester, but none of them would have L-T4 "recommended".

CONCLUSION

The findings of the study suggest that selective screening, recommended by ATA/AACE does not result in a significant loss of pregnant women with an indication for L-T4 treatment.

Exercise training improves quality of life in women with subclinical hypothyroidism: a randomized clinical trial

OBJECTIVE

The aim was to evaluate the quality of life (HRQoL) in women with subclinical hypothyroidism (sHT) after 16 weeks of endurance training.

SUBJECTS AND METHODS

In the first phase, a cross-sectional study was conducted in which 22 women with sHT (median age: 41.5 (interquartile range: 175) years, body mass index: 26.2 (8.7) kg/m2, thyroid stimulating hormone > 4.94 mIU/L and free thyroxine between 0.8 and 1.3 ng/dL were compared to a group of 33 euthyroid women concerned to HRQoL. In the second phase, a randomized clinical trial was conducted where only women with sHT were randomly divided into two groups: sHT-Tr (n = 10) - participants that performed an exercise program - and sHT-Sed (n = 10) - controls. Exercise training consisted of 60 minutes of aerobic activities (bike and treadmill), three times a week, for 16 weeks. The HRQoL was assessed by the SF-36 questionnaire in the early and at the end of four months.

RESULTS

Women with sHT had lower scores on functional capacity domain in relation to the euthyroid ones (770 ± 23.0 vs. 88.8 ± 14.6; p = 0.020). The sHT-Tr group improved functional capacity, general health, emotional aspects, mental and physical component of HRQoL after training period, while the sHT-Sed group showed no significant changes.

CONCLUSION

After 16 weeks of aerobic exercise training, there were remarkable improvements in HRQoL in women with sHT.

Maternal hypothyroxinemia in the first trimester of gestation and association with obstetric and neonatal outcomes and iron deficiency: a prospective Brazilian study

OBJECTIVE

To evaluate the association of isolated hypothyroxinemia in the first trimester with obstetric and neonatal outcomes and iron deficiency.

SUBJECTS AND METHODS

The study was prospective. Women who had become pregnant spontaneously were initially selected. Next, anti-thyroid peroxidase antibodies (TPOAb), free T4 (FT4), total T4 (TT4), TSH, and ferritin were measured. TPOAb-positive women were excluded. The final sample consisted of 596 women with serum TSH between 0.1 and 2.5 mIU/l. Hypothyroxinemia was defined as FT4 < 0.86 ng/dL and < 0.92 ng/dL, corresponding to the 5th and 10th percentiles, respectively, and TT4 < 7.8 ng/dL. None of the pregnant women was treated with levothyroxine until the end of pregnancy.

RESULTS

The women ranged in age from 18 to 36 years, with a median gestation of 9 weeks. T4 levels were not correlated with BMI or maternal TSH. Isolated hypothyroxinemia was observed in 4.3% (FT4 < 0.86 ng/dL), 9% (FT4 < 0.92 ng/dL), and 7% (TT4 < 7.8 ng/dL) of the pregnant women. The frequencies of obstetric and neonatal outcomes were similar in women with versus without hypothyroxinemia. In women without iron deficiency, 8.4%, 3.9%, and 6.5% had FT4 < 0.92 ng/dl, FT4 < 0.86 ng/dL and TT4 < 7.8 ng/dL, respectively. These frequencies of hypothyroxinemia were significantly higher among women with iron deficiency (20.7%, 14.8% and 17.2%, respectively).

CONCLUSIONS

This prospective Brazilian study found no association between isolated hypothyroxinemia in the first trimester of gestation and obstetric or neonatal outcomes, but an association was demonstrated with iron deficiency.

Serum TSH level stability after 5 years in euthyroid adults at low risk for thyroid dysfunction

OBJECTIVE

To evaluate changes in thyroid function after 5 years, the interval proposed for new assessment, in initially euthyroid adults.

SUBJECTS AND METHODS

Initially, 1,426 apparently healthy adults considered low risk for thyroid dysfunction, were evaluated by measurement of TSH. After 5 years, 1,215 (85.2%) subjects were reevaluated.

RESULTS

After 5 years, four subjects were receiving levothyroxine (L-T4) replacement therapy and 25 others had TSH > 4 mIU/L, only two of them with TSH > 10 mIU/L. All of these subjects had TSH > 3 mIU/L in the initial evaluation. During reassessment, none of the subjects had been or was treated for hyperthyroidism and 22 had TSH < 0.4 mIU/L (none of them < 0.1 mIU/L). Nineteen of these subjects had TSH ≤ 0.6 mIU/L in the initial evaluation. Among the 1,098 subjects with TSH between 0.6 and 3 mIU/L in the initial evaluation, reassessment showed that none of the subjects was using L-T4; only three had TSH > 4 mIU/L (none of them > 10 mIU/L); none had been or was treated for hyperthyroidism, and only three had TSH < 0.4 mIU/L (none of them < 0.1 mIU/L). These results did not differ between men and women or between subjects ≤ 60 and > 60 years.

CONCLUSION

Repeat TSH measurement within an interval of only 5 years would not be cost-effective in adults without known thyroid disease or risk factors for dysfunction who exhibit TSH between 0.6 and 3 mIU/L.

Metformin effect on TSH in subclinical hypothyroidism: randomized, double-blind, placebo-controlled clinical trial

INTRODUCTION

Non-randomized trials suggest that metformin may reduce TSH levels through unknown mechanisms.

OBJECTIVE

To evaluate whether metformin can reduce TSH levels in subjects with subclinical hypothyroidism.

PATIENTS AND METHODS

This is a randomized, double-blind, placebo controlled clinical trial with 3 months duration that enrolled 48 individuals, between 18 and 65 years, with subclinical hypothyroidism. The patients were randomized to the use of metformin 850 mg or placebo twice a day for 3 months. The primary outcome was the absolute decrease in TSH levels. Secondary outcomes were changes in the clinical and laboratory assessment, as well as in blood pressure assessed by ambulatory blood pressure monitoring.

RESULTS

After 3 months, 93.75% of participants completed the follow-up. The post treatment value of TSH in the metformin and placebo groups were 6.48 ± 3.11 and 7.02 ± 3.28 mIU/L, respectively (p = 0.57). Patients who achieved status of euthyroidism in the metformin and placebo groups were 21.7 and 18.2%, respectively (p = 0.76). There was no significant reduction of TSH within the groups [delta for TSH of 0.63 ± 0.56 (p = 0.28) and 0.54 ± 0.60 mIU/L (p = 0.38), in metformin and placebo groups, respectively]. There was a small increase in HDL cholesterol (1.62 ± 0.45 vs. 1.34 ± 0.39 mmol/L, p = 0.03) favoring the metformin group.

CONCLUSION

Since the sample size was small, the study was inconclusive and the results should be considered preliminary data of a study that needs to enroll 1626 patients to show a 0.5 mIU/L difference in TSH between the groups, with 90% power.

HIGH PREVALENCE OF HYPOTHYROIDISM IN SYSTEMIC LUPUS ERYTHEMATOSUS PATIENTS WITHOUT AN INCREASE IN CIRCULATING ANTI-THYROID ANTIBODIES

OBJECTIVE

Because routine investigations are necessary for the early detection of thyroid disease, this study aimed to assess the prevalence of autoimmune thyroid disease (ATD) and thyroid dysfunction (TD) in patients with systemic lupus erythematosus (SLE).

METHODS

Seventy-nine SLE patients (American College of Rheumatology criteria) and 159 control patients with no diagnosis of autoimmune diseases (except for ATD) were consecutively evaluated regarding changes in laboratory assessments of thyroid function and the presence of ATD.

RESULTS

ATD was detected in 11.4% of the SLE patients and 13.8% of the control patients (P = .747), whereas TD was detected in 25.3 and 9.4% (P = .002), hypothyroidism was detected in 21.5 and 6.9% (P = .002), and hyperthyroidism was detected in 3.8 and 2.5% (P = .426) of the SLE and control patients, respectively. The mean duration of SLE was longer in patients with TD (P = .036). Mild hypothyroidism was more frequent in the SLE patients with anti-Smith antibodies (P = .029).

CONCLUSION

Because hypothyroidism was more frequent in SLE patients and the frequency of ATD was high in both groups, the authors suggest that TSH and anti-thyroid antibody levels be assessed in SLE patients.

ABBREVIATIONS

ACA = anti-cardiolipin antibodies; ANF = anti-nuclear factor; anti-CCP = anti-cyclic citrullinated peptide; anti-dsDNA = anti-double-stranded DNA; anti-RNP = anti-ribonucleoprotein; anti-Scl70 = anti-topoisomerase I antibodies; anti-SM = anti-Smith antigen antibodies; anti-SS-A/Ro = anti-Sjögren syndrome-related antigen A (Ro); anti-SS-B/La = anti-Sjögren syndrome-related antigen B (La); anti-Tg = anti-thyroglobulin; anti-TPO = anti-thyroid peroxidase; ATD = autoimmune thyroid disease; ENA = extractable nuclear antigen; fT4 = free thyroxine; OR = odds ratio; RF = rheumatoid factor; SLE = systemic lupus erythematosus; SLEDAI = SLE Disease Activity Index; TD = thyroid dysfunction; TSH = thyroid-stimulating hormone; TT3 = total triiodothyronine.

Hypothyroidism in psychiatric patients

Introduction

Hypothyroidism psychocognitive key features may include melancholia, memory impairment, depression and dementia which could be misdiagnosed as a psychiatric disorder.

Objective

To study the incidence of hypothyroidism in psychiatric patients.

Methods

This retrospective study included 232 psychiatric patients with mean age of 43.39 ± 10 years old weight mean of 79.81 ± 19.07 kg, BIM of 29.55 ± 6.83, enrolled in a public mental health service.

Results

Twenty point twenty-one percent (39) patients presented hypothyroidism with thyroid-stimulating hormone (TSH) levels above 5 mIU/L and Free T4 levels below 0.7 ng/dl.

Comparing the incidence of hypothyroidism in Brazilian population estimated rate of until 10% [1] with this psychiatric patients population we observed a significant difference with p value of 2.28 E-6. Neuroleptics 92%(36), biperiden 62%(24) and benzodiazepines 38% (15) were the most frequent prescribed drugs for these hypothyroidism patients.

Conclusion

Significant difference in the incidence of hypothyroidism between general Brazilian population and the studied psychiatric patients was observed [2,3].

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Higher Carotid Intima-Media Thickness in Subclinical Hypothyroidism Associated with the Metabolic Syndrome

BACKGROUND

The subclinical hypothyroidism (SH) and the metabolic syndrome (MS) have been associated with increased risk of atherosclerosis and cardiovascular disease (CVD). The measurement of carotid intima-media thickness (IMT) is capable of detecting early signs of atherosclerotic disease. The goal of the study was to compare the carotid IMT of patients with SH with and without the MS.

METHODS

Twenty-nine SH patients were subdivided into two groups: one with MS (SH + MS) and one without MS (SH - MS). The study also assessed a group of euthyroid patients (n = 31), also subdivided into two groups: one with MS (EU + MS) and one without MS (EU - MS). The clinical and laboratory data and the mean and maximum carotid IMT of the groups were compared.

RESULTS

Maximum (P = 0.012) and mean (P = 0.025) IMT were higher in the SH + MS group than in the SH-MS group. Maximum IMT was higher in the SH + MS group than in the EU + MS group (P = 0.048). Maximum IMT was positively correlated with fasting glucose (FG; R = 0.621; P < 0.01) and body mass index (R = 0.258; P = 0.041) and negatively correlated with low-density lipoprotein cholesterol (LDL-C) (R = -0.297; P = 0.017). Mean IMT was positively correlated with FG (R = 0.580; P < 0.01), systolic blood pressure (R = 0.292; P = 0.02), and triglycerides (R = 0.250; P = 0.048) and negatively correlated with LDL-C (R = -0.288; P = 0.022).

CONCLUSIONS

SH + MS patients have higher IMT than SH - MS or EU + MS patients, suggesting that SH may be one more CVD risk factor in patients with the MS.

Evaluation of epicardial fat tissue thickness as a marker of cardiovascular risk in patients with subclinical hypothyroidism

BACKGROUND

Epicardial fat thickness (EFT) has been evaluated as a marker of cardiovascular disease, with good correlation with classical cardiovascular risk factors in the general population. The aim of this study was to evaluate the EFT in subclinical hypothyroidism (SCH), in comparison to a group without thyroid dysfunction.

METHODS

A cross-sectional study was performed with 100 participants, including 52 SCH patients and 48 individuals without any thyroid dysfunction (euthyroid group-EU). Transthoracic echocardiography (TE), thyroid hormone levels, lipid profile, and assessment of body composition by bioelectrical impedance (BIA) and anthropometry were measured in all subjects.

RESULTS

The SCH and EU groups were comparable with respect to age, gender, and Framingham risk scores. Serum thyroid-stimulating hormone (TSH) was 6.7 ± 1.4 mIU/L in the SCH group and 2.0 ± 0.84 mIU/L in the control group. EFT was similar in both groups (SCH 3.5 ± 1.3 mm, EU 3.5 ± 1.1 mm, p = 0.43). EFT showed a slight trend for a positive correlation with serum TSH in the SCH group (r s = 0.263, p = 0.05). EFT correlated with the body fat percentage in the SCH group (r s = 0.350, p = 0.03) and EU group (r s = 0.033, p = 0.04). EFT in this cohort was not independently correlated to changes in TSH and Framingham risk score.

CONCLUSIONS

EFT determination by TE does not seem to be a good marker of cardiovascular risk in SCH patients with serum TSH <10.0 mIU/L and no pre-existing cardiovascular morbidity.

Association between increased serum thyrotropin concentration and the oldest old: what do we know?

To assess studies that evaluate the relation between serum thyrotropin concentration, very old subjects, and their events. We searched the PubMed, SciELO, and LILACS databases for articles published between 2004 and 2012. Our search was restricted to studies involving humans aged 65 years or older, and written in English, Spanish, or Portuguese. Studies that evaluated the association between elevated serum thyrotropin concentration among elderly subjects with subclinical hypothyroidism were chosen since at least in part they included a subpopulation of individuals aged 80 years and above. Thirteen studies were selected. No significant increase in risk of cardiovascular events, coronary heart disease, or total mortality was observed. Elevated thyrotropin concentration was associated with longevity. More randomized controlled trials are required to better define the potential benefits of elevated thyrotropin concentration in this oldest old population, hormone replacement, and longevity.

Subclinical hypothyroidism represents an additional risk factor for coronary artery calcification, especially in subjects with intermediate and high cardiovascular risk scores

OBJECTIVE

Several studies have suggested an association between subclinical hypothyroidism (SCH) and increased cardiovascular risk. The aim of this study was to evaluate the presence of coronary artery disease (CAD) in asymptomatic patients with SCH by measuring the coronary artery calcium score (CACS).

DESIGN

A total of 222 asymptomatic subjects (103 SCH and 119 euthyroid (EU)), who were between the ages of 35 and 65 years and had no previous history of CAD, were enrolled for this cross-sectional analysis.

METHODS

The criteria for SCH included a confirmed normal serum free thyroxine and high TSH levels. Lipid profile, Framingham risk score (FRS) and CACS analyses were performed for all subjects.

RESULTS

The SCH and EU groups were comparable with respect to age, gender, BMI and frequency of diabetes, systemic arterial hypertension, hypercholesterolaemia and smoking. There was no difference in the median CACS between the SCH and EU groups. However, in the subgroup of subjects with intermediate/high FRS (AR10y ≥10%), CACS was higher in the SCH subjects compared with EU subjects (EU vs SCH, 0.0 (57.0) vs 23.0 (161.5); P=0.045). Multivariate analysis revealed that the risk for CACS >100 was independently associated with male gender, age >55 years, and the presence of simultaneous SCH and AR10y ≥10% (OR=87.5 (CI=2.1-3500); P=0.001). Serum TSH was positively correlated with CACS, especially in intermediate/high FRS subjects (rs=0.301, P=0.045).

CONCLUSIONS

It was demonstrated that SCH represents an additional risk factor for CAD, notably in intermediate and high FRS subjects.

Impact of thyroid status and age on comprehensive geriatric assessment

This study aimed to evaluate the prevalence of thyroid dysfunction in elderly subjects attending an outpatient clinic at a tertiary hospital and to assess whether subclinical hypothyroidism (SCH) or aging affected activities of daily living (ADLs), instrumental activities of daily living (IADLs), cognitive status, or depressive symptoms. This crosssectional study included 411 patients recruited in the outpatient geriatric setting. 48 subjects reported levothyroxine use and were evaluated separately. After excluding subjects with diseases or drugs which could influence thyroid status, the 284 subjects remaining were classified as having euthyroidism (n = 235, 82.8 %), subclinical hypothyroidism (n = 43, 15.1 %), subclinical hyperthyroidism (n = 4, 1.4 %), or overt hyperthyroidism (n = 2, 0.7 %). ADLs and IADLs were assessed using the Katz Index (ranging from 0 [independence] to 6 [dependence in all activities]) and Health Assessment Questionnaire (ranging from 0 to 3 [severely disabled]), respectively. Cognition was assessed using the mini mental state depressive symptoms that were assessed using the Geriatric depression scale or cornell scale for depression in dementia. SCH did not reduce performance in ADLs or IADLs in elderly subjects as a whole, but was an independent protective factor against dependence in ADLs (OR = 0.196 [0.045-0.853]; p = 0.003) and IADLs (OR = 0.060 [0.010-0.361]; p = 0.002) in subjects aged ≥85 years. Very old subjects with SCH showed better performance in ADLs than did those with euthyroidism (Katz Index: 0.9 ± 1.6 [median: 0.5] vs. 1.7 ± 1.7 [1.0], p = 0.024; HAQ: 1.2 ± 0.8 [0.9] vs. 1.8 ± 1.0 [1.9], p = 0.015). This putative protective effect of SCH was not found in subjects aged <85 years. The number of falls, number of medications used, depressive symptoms, and cognitive impairment did not differ among thyroid status groups, regardless of age. In conclusion, SCH does not have impact functional performance in the elderly population as a whole, but was associated with better functional status in subjects aged ≥85 years.