Inhibited 131I Uptake but Normal Release of Thyroid Hormone by Thyroid Gland in Response to TSH Administration in Subclinical Hypothyroidism

Background: Subclinical hypothyroidism is characterized by normal circulating thyroid hormone levels with super-normal TSH concentrations in absence of clinical manifestations. In majority of subjects, an etiologic factor is often identified. Moreover, therapy with levothyroxine normalizes serum TSH concentration while maintaining normal thyroid hormone concentrations. However, the exact pathophysiology of these thyroid hormone alterations is not well defined. Objective: Major steps in synthesis i.e. iodine uptake and the release of thyroid hormones in response to SC TSH administration were assessed in subjects with subclinical hypothyroidism. Methods: 10 men and 5 women with subclinical hypothyroidism, ages 42 - 76 years and 10 euthyroid men (39 - 70 years) participated. 24 hr 131Iodine thyroid uptake and serum T3, T4 and TSH concentrations were determined prior to and after SC administration of recombinant human TSH, 0.9 mg for two consecutive days. Comparisons were conducted for 24 hour uptake values as well as serum T3, T4 and TSH levels obtained prior to and after TSH administration. Results: In subjects with subclinical hypothyroidism 24 hour 131I thyroidal uptakes were normal (10% - 30%). However, the mean value was significantly lower, (p 3 and T4 concentrations in subjects with subclinical hypothyroidism were not significantly different in comparison to normal subjects. Serum TSH concentrations were supernormal and therefore were significantly higher in subjects with subclinical hypothyroidism in comparison to normal subjects and rose markedly in both groups following TSH administration with no significant difference among groups. Serum T4 and T3 rose significantly from PreTSH levels in both groups (p 131I Thyroid uptake is inhibited prior to as well as following SC TSH administration in comparison to normal subjects with maintenance of normal hormone release.

Prevalence of hypothyroidism and effect of thyroid hormone replacement therapy in patients with non-alcoholic fatty liver disease:A population-based study

BACKGROUND Non-alcoholic fatty liver disease(NAFLD)is currently considered as the most common cause of chronic liver disease worldwide.Risk factors for NAFLD have been well-described,including obesity,type 2 diabetes mellites(T2DM),dyslipidemia(DLP)and metabolic syndrome.Hypothyroidism has been identified as an independent risk factor for the development of NAFLD,although the literature is inconsistent AIM To evaluate the prevalence of hypothyroidism in patients with NAFLD,assess if it is an independent risk factor and explore the effect of thyroxine replacement therapy.METHODS Our cohort’s data was obtained using a validated,large,multicenter database(Explorys Inc,Cleveland,OH,United States)aggregated from pooled outpatient and inpatient records of 26 different healthcare systems,consisting of a total of 360 hospitals in the United States,and utilizing Systematized Nomenclature of Medicine-Clinical Terms for coding.We evaluated a cohort of patients with hypothyroidism and NAFLD.Multivariate analysis was performed to adjust for confounding risk factors including hypertension(HTN),T2DM,DLP,obesity and metabolic syndrome.SPSS version 25,IBM Corp was used for statistical analysis,and for all analyses,a 2-sided P value of<0.05 was considered statistically significant.Exclusion criteria were limited to age<18 years.RESULTS Among the 37648180 included individuals in this database who are above the age of 18 years,there were a total of 2320 patients with NAFLD(6.16 per 100000)in the last five years(2015-2020),amongst which 520 patients(22.4%)had hypothyroidism.Baseline characteristics of patients in this database are described in Table 1.Patients with NAFLD were also more likely to have obesity,T2DM,DLP,HTN,and metabolic syndrome(Table 2).While males and females were equally affected,patients in the age group 18-65 years as well as Caucasians seem to be at a higher risk.There was an increased risk of NAFLD among patients with hypothyroidism(OR=1.587).Furthermore,thyroid hormone replacement was not associated with a decreased risk for developing NAFLD(OR=1.106,C=0.952-1.285,P=0.303).CONCLUSION Hypothyroidism seems to be an independent risk factor for the development of NAFLD.Thyroid hormone replacement did not provide a statistically significant risk reduction.Further studies are needed to evaluate the effect of thyroid hormone replacement and assess if being euthyroid while on thyroid replacement therapy affects development and/or progression of NAFLD.

Changes in confirmed plus borderline cases of congenital hypothyroidism in California as a function of environmental fallout from the Fukushima nuclear meltdown

Radiation exposure has been linked to increased risk of congenital hypothyroidism (CH) for decades. CH is a relatively uncommon condition, occurring in about 1 of 2000 US births. Thyroid Stimulating Hormone (TSH) levels for each child born in California permitted an analysis of combined confirmed and borderline CH cases. Borderline/confirmed CH cases are more than seven times greater than just confirmed cases. Airborne levels of gross beta nuclear radiation in the US were elevated in the period starting several days after the Fukushima nuclear meltdown, especially in west coast states like California. The borderline/confirmed CH rate for newborns during the last 9.5 months in 2011 (exposed to Fukushima in utero) vs. births during other periods in 2011 and 2012 (not exposed) was significantly elevated, suggesting that adverse health effects to the newborn thyroid were not restricted to just a small number of confirmed CH cases. The sensitivity of the fetus to radiation exposure, plus the presence of thyroid-seeking radioiodine, suggest further analysis of Fukushima’s potential to cause adverse health effects in newborns is needed.

Drug-Induced Hypothyroidism during Anti-Tuberculosis Treatment of Multidrug-Resistant Tuberculosis: Notes from the Field

We followed 188 euthyroidic persons undergoing treatment for multidrug resistant tuberculosis (MDR-TB) in the state of Karnataka, India to determine the incidence of hypothyroidism during anti-tuberculosis treatment. Overall, among MDR-TB patients with valid thyroid stimulating hormone (TSH) values, about 23% developed hypothyroidism (TSH value ≥10 mIU/ml) during anti-tuberculosis treatment;the majority (74%) occurring after 3 months of treatment. Among 133 patients who received a regimen that contained ethionamide, 42 (32%) developed hypothyroidism. Among 17 patients that received a regimen that contained para-aminosalicylate sodium, 6 (35%) developed hypothyroidism. Among 9 HIV positive patients on antiretroviral treatment, 4 (44%) developed hypothyroidism. These results differ from previously reported 4% incidence of hypothyroidism amongst patients who passively reported thyroidal symptoms during treatment, suggesting routine serologic monitoring of TSH throughout the course of treatment for MDR-TB is warranted.

Correlation of Cognitive Performance and Thyroid Hormone Levels in Adolescents with Subclinical Hypothyroidism

Subclinical hypothyroidism (SCH) can negatively affect cognitive functioning. This study aimed at correlating serum T3, T4, TSH with adolescent’s performance on a learning disability scale. Methods: A cross-sectional study was conducted on 100 schoolchildren, (10 - 15 years). Thyroid hormones were estimated and classified into two groups: euthyroid and subclinical hypothyroid. NIMHANS index for Specific Learning Disabilities was used to assess the learning ability and cognitive functions. Results: Subclinical hypothyroid group made more mistakes than euthyroid group. In SCH male group, T3 correlated with language and T4 levels correlated in all areas except in language. In the females, there is no significant correlation between T3 and ability parameters except in partial correlation coeffeicient among euthyroid children in arithmetic, visual-motor skills and memory. T4 results did not correlate in language skills. There was a statistical significance between T4 and ability skills in girls except in language. TSH and language skills correlated in females. Conclusion: T3 and T4 levels have correlation with cognitive skills other than TSH. It is necessary to measure both T3 and T4 in addition to TSH in adolescents.

Cardiac tamponade as the initial manifestation of severe hypothyroidism: A case report

Background: Hypothyroidism is a commonly seen condition. The presence of pericardial effusion with cardiac tamponade as initial manifestation of this endocrinological condition is very unusual. Objectives: In hypothyroidism pericardial fluid accu-mulates slowly, allowing adaptation and stretching of the pericardial sac, sometimes accommodating a large volume. Case Report: A 39 year-old female presented with chest pain, dyspnea and lower extremity edema for 1 day. Bradycardia, muffled heart sounds and severe hypertension were noticed. Chest radiograph showed an enlarged cardiac silhouette. A bedside echocardiogram revealed a cardiac tamponade, later she developed sudden hypotension and bradycardia that resolved after pericardiocentesis of 1 liter of pericardial fluid. The further laboratory evaluation revealed a TSH value of 69.3 miU/L and low T3 and free T4. The patient later developed reaccumulation of pericardial fluid with the need for creation of pericardial window. Conclusion: When the classic Beck’s triad is not present and bradycardia accompanies a cardiac tamponade, hypothyroidism should be strongly suspected. The requirement for thyroid hormone supplement is critical and is well reported. There is a chance of recurrence even after starting levothyroxine supplementation;and the associated hypertension usually requires treatment with more than one drug.

Effects of gestational subclinical hypothyroidism and TPO-Ab on pregnancy outcomes

The prevalence of gestational subclinical hypothyroidism has been increasing with years, and it has become one of the common diseases happened to women during pregnancy in China. Gestational subclinical hypothyroidism can not only increase the incidence of adverse pregnancy outcomes, but also have a negative impact on the development of the offspring. Therefore, it is necessary to make an early detection, diagnosis and treatment.

Hypothyroidism in Childhood and Adolescence

Juvenile hypothyroidism is an unfrequent form of hypothyroidism that affects children. If not diagnosed and treated properly, it may cause severe neurological disorders during growth. The most frequent difficulties are found in school performance, difficulties in concentration, hyperactivity or fatigue and damage on the onset of puberty. Starting levothyroxine as a drug of choice is essential, and it should be made according to the age and weight of the child. Laboratory tests for control should be requested periodically, along with a strict control of the child’s development and growth. The family-doctor relationship, along with a clear guidance on the importance of treatment, is critical to achieve a successful treatment. This article is a review about the main clinical features of hypothyroidism in childhood, especially in developing countries, providing key aspects of adherence and characteristics of its follow-up.

Diabetes mellitus and hypothyroidism: Strange bedfellows or mutual companions?

Clinicians should be cognizant of the close relationship that exists between two of the most common endocrine disorders, primary hypothyroidism and diabetes mellitus. This applies to patients with both type 1 and type 2 diabetes mellitus(T1DM and T2 DM respectively). However, the association is greater in T1 DM, probably because of the shared autoimmune predisposition. In patients with T2 DM, the relationship is somewhat weaker and the explanation less clear-cut. Factors such as dietary iodine deficiency, metformin-induced thyroid stimulating hormone suppression and poor glycemic control may all be implicated. Further translational research is required for greater clarification. Biochemical screening for abnormal thyroid function in individuals who have diabetes is warranted, particularly in females with T1 DM, and therapy with L-thyroxine appropriately instituted if hypothyroidism is confirmed.

Hypothyroidism affects astrocyte and microglial morphology in type 2 diabetes

In the present study, we investigated the effects of hypothyroidism on the morphology of astrocytes and microglia in the hippocampus of Zucker diabetic fatty rats and Zucker lean control rats. To induce hypothyroidism, Zucker lean control and Zucker diabetic fatty rats at 7 weeks of age orally received the vehicle or methimazole, an anti-thyroid drug, treatment for 5 weeks and were sacrificed at 12 weeks of age in all groups for blood chemistry and immunohistochemical staining. In the me- thimazole-treated Zucker lean control and Zucker diabetic fatty rats, the serum circulating triiodo- thyronine （T3） and thyroxine （＇I＂4） levels were significantly decreased compared to levels observed in the vehicle-treated Zucker lean control or Zucker diabetic fatty rats. This reduction was more prominent in the methimazole-treated Zucker diabetic fatty group. Glial fibrillary acidic protein im- munoreactive astrocytes and ionized calcium-binding adapter molecule 1 （Iba-1）-immunoreactive microglia in the Zucker lean control and Zucker diabetic fatty group were diffusely detected in the hippocampal CA1 region and dentate gyrus. There were no significant differences in the glial fibril- lary acidic protein and Iba-1 immunoreactivity in the CA1 region and dentate gyrus between Zucker lean control and Zucker diabetic fatty groups. However, in the methimazole-treated Zucker lean control and Zucker diabetic fatty groups, the processes of glial fibrillary acidic protein immunoreac- tive astrocytes and Iba-1 immunoreactive microglia, were significantly decreased in both the CA1 region and dentate gyrus compared to that in the vehicle-treated Zucker lean control and Zucker diabetic fatty groups. These results suggest that diabetes has no effect on the morphology of as- trocytes and microglia and that hypothyroidism during the onset of diabetes prominently reduces the processes of astrocytes and microglia.

Hypothyroidism during pregnancy: Controversy over screening and intervention

Thyroid hormones are critical for foetal neurological development and maternal health. Maternal hypothyroidism during pregnancy is associated with adverse impact on health of the mother as well as the progeny. Reduced thyroid hormone levels predispose the child to develop mental retardation and cognitive delay in early life. In the mother, hypothyroidism during pregnancy is associated with spontaneous abortion, placental abruption, preterm delivery and hypertensive disorders. Therefore, screening and therapeutic intervention is justified to prevent foetal as well as maternal co-morbidities. In view of impact of such a large-scale screening and intervention program on limited healthcare resources, it is debatable if a targeted rather than universal screening program will result in comparable outcomes. In addition, there is an ongoing debate regarding best evidence-based practice for the management of isolated hypothyroxinaemia, subclinical hypothyroidism and euthyroid women with autoimmune hypothyroidism. We have carried out a review of the literature; firstly, to determine whether universal screening for asymptomatic women in early pregnancy would be cost-effective. Secondly, we have retrospectively reviewed the literature to analyse the evidence regarding the impact of therapeutic intervention in women with subclinical hypothyroidism.

Is nitric oxide level affected in postmenopausal women with hypothyroidism?

AIMTo analyze serum levels of nitric oxide （NO）, an indicator of cardiovascular health, in post-menopausal females with and without hypothyroidism. METHODSNO was analyzed colorimetrically in 30 newly diag-nosed hypothyroid postmenopausal females and 30 postmenopausal females with normal thyroid profle. Results were compared and subjected to appropriate statistical analysis. RESULTSThe levels of serum NO were found to be significantlydecreased in postmenopausal females with hypothyroidismas compared to the levels in those with normal thyroidprofile （P value 〈 0.05）. A negative correlation of NOwas observed with thyroid stimulating hormone whereasa positive correlation of NO was observed with free T3 （FT3）, free T4 （FT4）, T3 and T4 though it was statistically signifcant only for FT4 among postmenopausal females with hypothyroidism.CONCLUSIONPostmenopausal hypothyroid females may be at a risk of compromised cardiovascular health as indicated by low NO levels. Regular monitoring and risk assessment is essential for timely intervention.

Subclinical hypothyroidism in atopic South Italian children

AIM:To verify if subclinical hypothyroidism(SCH) could be associated to atopy in children.METHODS:Seven hundred and thirty-two Caucasian children from South Italy presenting symptoms of allergic disease were enrolled and submitted to atopy,obesity,chronic low grade inflammation,and SCH work up.RESULTS:Four hundred and forty-five out of 705(63.12%) children affected by allergic disease were diagnosed as atopic and 260(36.88%) as not atopic.The SCH prevalence was 6.3%.Significant higher prevalence of SCH among atopic children with average(group 2) and high(group 3) low grade chronic inflammation compared to atopic children with mild(group 1)low grade chronic inflammation was present.Moreover,group 1 and group 2 presented an OR to show SCH of2.57(95%CI:1.55-6.26) and 2.96(95%CI:1.01-8.65),respectively.Both in atopic and not atopic children we found C3 serum levels significantly higher in group 3respect to group 2 and group 1.Noteworthy,among atopic patients,also total immunoglobulin E(IgE) serum levels,were significantly higher in group 3 compared to group 2 and group 1 children.In atopic children,C3 and total IgE serum values increased in parallel with the increase of C-reactive protein values,while in not atopic children this phenomenon was not evident.CONCLUSION:The possibility exists that an increasing atopic inflammation contributes to SCH occurrence.So far this is the first report in literature showing an association between SCH and atopy but further studies are needed to confirm our data.

Short-term overt hypothyroidism affect on lipids after thyroxine-withdrawal in patients with differentiated thyroid carcinoma

Objective: The aim of the study was to investigate the effects of short-term overt hypothyroidism on lipids after thyroxine-withdrawal in patients with iatrogenically induced hypothyroidism before radioiodine treatment for differentiated thyroid carcinoma (DTC). Methods: Thirty patients with a history of differentiated thyroid carcinoma on thyroid-stimulating hormone (TSH)-suppressive thyroxine replacement therapy were studied. Blood sample were taken before and 4 weeks after withdrawal of thyroxine substitution. Venous blood was drawn after an overnight fast and analyzed for serum free T4 (FT4), free T3 (FT3), thyroid-stimulating hormone (TSH), total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB). Fifty healthy people matched for age and gender were controls. Their blood samples were taken only once. Results: After thyroxine-withdrawal, the patients presented with increased serum TSH and low serum FT4 and FT3 levels compared with controls. Serum TG, TC, LDL, HDL, ApoB and Lp(a) increased after thyroxine withdrawal, reaching statistical significant differences with previous evaluation. However, when compared to euthyroid controls, only TC, LDL and ApoB were increased when patients were hypothyroidism. No changes were observed in ApoA1 in patients during thyroxine withdrawal, or when comparing the values observed in patients to those of euthyroid controls. Conclusion: TG, TC, LDL, HDL, ApoB and Lp(a) were increased during short-term overt hypothyroidism.

Unilateral Periorbital Oedema with Hypothyroidism and Multinodular Goiter

Thyroid associated ophthalmopathy is an autoimmune disorder which involves orbital and periorbital tissue. The immune-mediated inflammation of the orbital tissues can involve extraocular muscles, orbital connective tissue or orbital fat and periocular soft tissues. Bilateral involvement of thyroid associated orbitopathy is usually asymmetric, but unilateral thyroid associated orbitopathy has been less reported. Periorbital oedema as the only sign with hypothyroidism is uncommon and if present, it is more frequent bilaterally present and no cases are evidenced as unilateral. Pitting oedema in hypothyroidism is rare and can be due to increased capillary permeability, decreased adrenergic tone and increase in serotonin metabolism. Unilateral periorbital and eyelid oedema can associate with various clinical entities, multidisciplinary team is necessary to exclude the concomitant disease, so the patient can immediately be treated with proper therapy. We represent the case of unusually unilateral recurrent periorbital oedema in the period of time for 3 years with stabilized primary hypothyroidism and multinodular goitre.

Vogt-Koyanagi-Harada syndrome associated to hypothyroidism revealed by myocarditis

Purpose: Vogt-Koyanagi-Harada (VKH) syndrome is usually defined as an uveo-meningitis who may be associated with auditory and cutaneous signs. Association of VKH syndrome and autoimmune thyroiditis is uncommon. Observation: A 28-year-old man was admitted with thoracic pain due to myocarditis. Two years ago he presented VKH syndrome with specific ocular manifestation and deafness, treated by corticosteroids and immunosuppressive. Etiologic investigation of myocarditis concluded to deep hypothyroidism related to Hashimoto thyroiditis. The patient improved after substitutive treatment by thyroid hormones. Conclusion: Thyroid function should be systematically investigated in case of VKH syndrome and particularly when associated to dysthyroidism symptoms.

A comparative study of influential factors correlating with early and late hypothyroidism after ^131I therapy for Graves＇ disease

Background 131Ⅰ therapy is recognized as the simplest, safest, least expensive, and most effective treatment, and accepted by more and more patients. However its curative effect is influenced by many factors, therefore there are some difficulties for doctors to establish individual treatment strategy. The aims of this study were to determine the incidence of early and late hypothyroidism after 131Ⅰ treatment for Graves＇ disease （GD） and to compare their correlation, to observe and analyze the influential factors and to understand the predictabilities of them.Methods Five hundred GD patients （144 males, 356 females; age （41.2±12.3） years） received 131Ⅰ treatment for the first time. The therapeutic procedure was carried out as the following： undergoing 131Ⅰ uptake test to obtain maximum of thyroid uptake value and effective half-life （EHL） time; estimating the thyroid＇s weight by ultrasonography; determination of thyroid hormones and correlative antibodies; pre-therapy physical examination; thyroid imaging; calculating 131Ⅰtherapeutic dosage; per os uptake of the determined 131Ⅰ dosage; follow-up appraisal of curative effect. The observing parameters included age, gender, thyroid weight, GD duration, condition of onset, state of disease, course of treatment, EHL time, maximum of thyroid uptake value, 131Ⅰ dosage and titer of correlative antibodies. We sorted out the data and used both univariate and multivariate analysis to evaluate them statistically.Results The incidence rates of early and late hypothyroidism were 33.2% and 6.6% respectively after 131Ⅰ treatment and approximately 22.2% cases of late hypothyroidism developed from early hypothyroidism. The influential factors of early hypothyroidism included course of GD, the highest thyroid uptake ratio of 131Ⅰ, EHL time and thyroid microsome antibody （TMAb）, etc. A multivariate analysis on late hypothyroidism showed that female patients, with recurrence after anti-thyroid drug treatment and higher thyroid weight, had lower possibility of late hypothyroidism after 131Ⅰ therapy.Conclusions The incidence of early hypothyroidism is higher than that of late hypothyroidism. The highest thyroid uptake ratio of 131Ⅰ, EHL and TMAb will increase the possibility of early hypothyroidism, while GD course is the protective factor. Higher 131Ⅰ dosage, longer EHL and higher TMAb titer will also increase the possibility of late hypothyroidism. The multi-perspective and multi-factor analysis has the benefit to establish individualized treatment strategy.

Evaluation and management of the child with hypothyroidism

Background Thyroid hormones are critical for early neurocognitive development as well as growth and development throughout childhood.Prompt recognition and treatment of hypothyroidism is,therefore,of utmost importance to optimize physical and neurodevelopmental outcomes.Data sources A PubMed search was completed in Clinical Queries using the key terms 'hypothyroidism'.Results Hypothyroidism may be present at birth (congenital hypothyroidism) or develop later in life (acquired hypothyroidism).Thyroid dysgenesis and dyshormonogenesis account for approximately 85% and 15% of permanent cases of congenital primary hypothyroidism,respectively.More than 95% of infants with congenital hypothyroidism have few,if any,clinical manifestations of hypothyroidism.Newborn screening programs allow early detection of congenital hypothyroidism.In developed countries,Hashimoto thyroiditis is the most common cause of goiter and acquired hypothyroidism in children and adolescents.Globally,iodine deficiency associated with goiter is the most common cause of hypothyroidism.Central hypothyroidism is uncommon and may be associated with other congenital syndromes and deficiencies of other pituitary hormones.Familiarity of the clinical features would allow prompt diagnosis and institution of treatment.Conclusions To optimize neurocognitive outcome in infants with congenital hypothyroidism,treatment with levothyroxine should be started as soon as possible,preferably within the first 2 weeks of life.Children with acquired hypothyroidism should also be treated early to ensure normal growth and development as well as cognitive outcome.The target is to keep serum TSH < 5 mIU/L and to maintain serum free T4 or total T4 within the upper half of the age-specific reference range,with elimination of all symptoms and signs of hypothyroidism.

Genetics of congenital hypothyroidism: Modern concepts

Congenital hypothyroidism (CH) is the most common neonatal endocrine disorder and one of the most common preventable causes of intellectual disability in the world. CH may be due to developmental or functional thyroid defects (primary or peripheral CH) or be hypothalamic-pituitary in origin (central CH). In most cases, primary CH is caused by a developmental malformation of the gland (thyroid dysgenesis, TD) or by a defect in thyroid hormones synthesis (dyshormonogenesis, DH). TD represents about 65% of CH and a genetic cause is currently identified in fewer than 5% of patients. The remaining 35% are cases of DH and are explained with certainty at the molecular level in more than 50% of cases. The etiology of CH is mostly unknown and may include contributions from individual and environmental factors. In recent years, the detailed phenotypic description of patients, high-throughput sequencing technologies, and the use of animal models have made it possible to discover new genes involved in the development or function of the thyroid gland. This paper reviews all the genetic causes of CH. The modes by which CH is transmitted will also be discussed, including a new oligogenic model. CH is no longer simply a dominant disease for cases of CH due to TD and recessive for cases of CH due to DH, but a far more complex disorder.

The incidence of adverse clinical outcome in acute coronary syndrome patients with subclinical hypothyroidism

Background Subclinical hypothyroidism is associated with adverse cardiovascular outcomes.But less is known about its prognostic role in patients with acute coronary syndrome(ACS).Methods 538 ACS patients with normal serum concentrations of T3 and T4 underwent coronary angiography in our hospital from January 2015 to January 2019 were retrospectively enrolled.They were divided into normal thyroid stimulating hormone(TSH)group(0.27-4.2 uIU/mL)(n=385)and high TSH group(>4.2 uIU/mL)(n=135).The study endpoints were the major adverse cardiovascular events(MACEs).The univariate and multivariate regression analysis including significant covariables were performed to test for the association between subclinical hypothyroidism and MACEs.Results The mean concentration of TSH were 8.72(6.37-11.02)uIU/mL in the high TSH group and 1.94(1.34-2.45)uIU/mL in the normal TSH group.Multivariate logistic regression analysis found that subclinical hypothyroidism[Odds ratio(OR):1.94,95%confidence interval(CI):1.23-2.65,P=0.030]was associated independently with MACE rate in ACS patients.The area under the receiver operating characteristic curve showed that the subclinical hypothyroidism had good predictable value for MACEs in patients with ACS(area under the curve:0.713,95%CI:0.668-0.802,P<0.001).Conclusions Subclinical hypothyroidism is associated with worse clinical prognosis in ACS patients.Clinicians need to pay more attention to subclinical hypothyroidism in ACS patients.[S Chin J Cardiol 2021;22(1):1-6]