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Pearce SHS, Brabant G, Duntas LH, Monzani F, Peeters RP, Razvi S, Wemeau JL. 2013 ETA Guideline: Management of Subclinical Hypothyroidism. Eur Thyroid J 2013; 2:215-28. [PMID: 24783053 PMCID: PMC3923601 DOI: 10.1159/000356507] [Citation(s) in RCA: 474] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Accepted: 10/07/2013] [Indexed: 01/08/2023] Open
Abstract
Subclinical hypothyroidism (SCH) should be considered in two categories according to the elevation in serum thyroid-stimulating hormone (TSH) level: mildly increased TSH levels (4.0-10.0 mU/l) and more severely increased TSH value (>10 mU/l). An initially raised serum TSH, with FT4 within reference range, should be investigated with a repeat measurement of both serum TSH and FT4, along with thyroid peroxidase antibodies, preferably after a 2- to 3-month interval. Even in the absence of symptoms, replacement therapy with L-thyroxine is recommended for younger patients (<65-70 years) with serum TSH >10 mU/l. In younger SCH patients (serum TSH <10 mU/l) with symptoms suggestive of hypothyroidism, a trial of L-thyroxine replacement therapy should be considered. For such patients who have been started on L-thyroxine for symptoms attributed to SCH, response to treatment should be reviewed 3 or 4 months after a serum TSH within reference range is reached. If there is no improvement in symptoms, L-thyroxine therapy should generally be stopped. Age-specific local reference ranges for serum TSH should be considered in order to establish a diagnosis of SCH in older people. The oldest old subjects (>80-85 years) with elevated serum TSH ≤10 mU/l should be carefully followed with a wait-and-see strategy, generally avoiding hormonal treatment. If the decision is to treat SCH, then oral L-thyroxine, administered daily, is the treatment of choice. The serum TSH should be re-checked 2 months after starting L-thyroxine therapy, and dosage adjustments made accordingly. The aim for most adults should be to reach a stable serum TSH in the lower half of the reference range (0.4-2.5 mU/l). Once patients with SCH are commenced on L-thyroxine treatment, then serum TSH should be monitored at least annually thereafter.
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Persani L, Brabant G, Dattani M, Bonomi M, Feldt-Rasmussen U, Fliers E, Gruters A, Maiter D, Schoenmakers N, van Trotsenburg AP. 2018 European Thyroid Association (ETA) Guidelines on the Diagnosis and Management of Central Hypothyroidism. Eur Thyroid J 2018; 7:225-237. [PMID: 30374425 PMCID: PMC6198777 DOI: 10.1159/000491388] [Citation(s) in RCA: 124] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 06/19/2018] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVES Central hypothyroidism (CeH) is a rare form of hypothyroidism characterized by insufficient thyroid stimulation due to disturbed pituitary and/or hypothalamic functioning. Due to its origin and the whole clinical context, CeH represents a challenging condition in clinical practice as it is characterized by suboptimal accuracy of clinical and biochemical parameters for diagnosis and management. Since no expert consensus or guidance for this condition is currently available, a task force of experts received the commitment from the European Thyroid Association (ETA) to prepare this document based on the principles of clinical evidence. STUDY DESIGN The task force started to work in February 2017 and after a careful selection of appropriate references (cohort studies, case reports, expert opinions), a preliminary presentation and live discussion during the 2017 ETA meeting, and several revision rounds, has prepared a list of recommendations to support the diagnosis and management of patients with CeH. RESULTS Due to the particular challenges of this rare condition in the different ages, the target users of this guidance are pediatric and adult endocrinologists. Experts agreed on the need to recognize and treat overt CeH at all ages, whereas treatment of milder forms may be dispensable in the elderly (> 75 years). CONCLUSIONS Despite the lack of randomized controlled clinical trials, the experts provide 34 recommendations supported by variable levels of strength that should improve the quality of life of the affected patients and reduce the metabolic and hormonal consequences of inadequate management.
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Delitala AP, Fanciulli G, Maioli M, Delitala G. Subclinical hypothyroidism, lipid metabolism and cardiovascular disease. Eur J Intern Med 2017; 38:17-24. [PMID: 28040402 DOI: 10.1016/j.ejim.2016.12.015] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 12/16/2016] [Accepted: 12/19/2016] [Indexed: 12/13/2022]
Abstract
Subclinical hypothyroidism is defined by elevated serum thyrotropin in presence of normal free thyroid hormones. Lipid metabolism is influenced by thyroid hormone and many reports showed that lipids status worsen along with TSH level. Subclinical hypothyroidism has been also linked to other cardiovascular risk factors such as alteration in blood pressure and increased atherosclerosis. Further evidences suggested that mild dysfunction of thyroid gland is associated with metabolic syndrome and heart failure. Thyrotropin level seems the best predictor of cardiovascular disease, in particular when its levels are above 10mU/L. However, despite these observations, there is no clear evidence that levothyroxine therapy in subjects with milder form of subclinical hypothyroidism could improve lipid status and the other cardiovascular risk factors. In this review, we address the effect of thyroid hormone and cardiovascular risk, with a focus on lipid metabolism.
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Association between subclinical hypothyroidism and depression: an updated systematic review and meta-analysis. BMC Psychiatry 2019; 19:12. [PMID: 30621645 PMCID: PMC6325749 DOI: 10.1186/s12888-018-2006-2] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 12/27/2018] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Although depression is associated with changes in the hypothalamic-pituitary-thyroid axis, its relationship with subclinical hypothyroidism (SCH) is controversial. To date, there is a lack of data on the improvement of depressive symptoms with levothyroxine therapy among individuals with coexistent SCH. METHODS We conducted a meta-analysis to evaluate the association between SCH and depression including 1) the prevalence of depression in SCH (with a sub-analysis of the geriatric cohort), 2) thyroid stimulating hormone (TSH) level among patients with depression and 3) the effect of levothyroxine therapy among patients with SCH and coexistent depression. RESULTS In a pooled analysis of 12,315 individuals, those with SCH had higher risk of depression than euthyroid controls (relative risk 2.35, 95% confidence intervals [CI], 1.84 to 3.02; p < 0.001). Geriatric cohort with SCH had a 1.7-fold higher risk of depression compared with healthy controls (odds ratio 1.72, CI, 1.10 to 2.70; p = 0.020). There was no difference in the mean TSH level between individuals with depression and healthy controls (2.30 ± 1.18 vs. 2.13 ± 0.72 mIU/L, p = 0.513). In individuals with SCH and coexistent depression, levothyroxine therapy was neither associated with improvement in the Beck Depression Inventory scoring (pooled d + = - 1.05, CI -2.72 to 0.61; p = 0.215) nor Hamilton Depression Rating Scale (pooled d + = - 2.38, CI -4.86 to 0.10; p = 0.060). CONCLUSION SCH has a negative impact on depression. Early and routine screening of depression is essential to prevent morbidity and mortality. However, the use of levothyroxine among patients with SCH and coexistent depression needs to be individualized.
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Abstract
Subclinical thyroid disease is defined biochemically by an abnormal thyrotropin (TSH) level and normal serum-free thyroxine level. The prevalence of this condition varies according to the reference range for TSH and geographic or demographic factors. Recently, several studies, including our community-based cohort studies, have reported on the incidence of subclinical thyroid disease in Korea. Using these studies, we reviewed the prevalence and risk factors of subclinical thyroid disease, focusing on subclinical hypothyroidism.
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Review |
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Mendes D, Alves C, Silverio N, Batel Marques F. Prevalence of Undiagnosed Hypothyroidism in Europe: A Systematic Review and Meta-Analysis. Eur Thyroid J 2019; 8:130-143. [PMID: 31259155 PMCID: PMC6587201 DOI: 10.1159/000499751] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 03/19/2019] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Patients with undiagnosed hypothyroidism are not treated for the disease and are at high risk of developing serious complications, with major impact on public health. There is a need to systematically review the available evidence on this topic. OBJECTIVE To identify the prevalence of undiagnosed hypothyroidism in Europe. METHODS A systematic review of the literature (Medline, EMBASE, and Cochrane Central) was performed to identify epidemiological studies on the prevalence of undiagnosed hypothyroidism among European populations published between January 2008 and April 2018. The Newcastle-Ottawa Scale was used to assess the methodological quality of the included studies. Random-effects meta-analyses were performed to pool estimates of proportions (with 95% confidence intervals [CIs]) of undiagnosed (1) subclinical, (2) overt, and (3) total hypothyroidism. RESULTS The search returned 15,565 citations (4,526 duplicates). Twenty papers were included in the study. Fourteen and 6 studies were of good and moderate methodological quality, respectively. The results of the meta-analyses were as follows for the prevalence of undiagnosed hypothyroidism: subclinical, 4.11% (95% CI 3.05-5.31%, I2 = 99.32%); overt, 0.65% (95% CI 0.38-0.99%, I2 = 96.67%); and total, 4.70% (95% CI 2.98-6.79%, I2 = 99.53%). According to the sensitivity analysis, the prevalence of hypothyroidism tends to be higher in female patients, in those aged ≥65 years, among studies with lower sample sizes, in those with thyroid-stimulating hormone levels <4.5 mIU/L, and in Eastern and Southern Europe. CONCLUSIONS The current evidence suggests that a considerable proportion of the European population has hypothyroidism, particularly subclinical hypothyroidism, which is undiagnosed. This issue deserves further investigation because of possible deleterious consequences for public health.
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Aziz M, Kandimalla Y, Machavarapu A, Saxena A, Das S, Younus A, Nguyen M, Malik R, Anugula D, Latif MA, Humayun C, Khan IM, Adus A, Rasool A, Veledar E, Nasir K. Effect of Thyroxin Treatment on Carotid Intima-Media Thickness (CIMT) Reduction in Patients with Subclinical Hypothyroidism (SCH): a Meta-Analysis of Clinical Trials. J Atheroscler Thromb 2017; 24:643-659. [PMID: 28566564 PMCID: PMC5517537 DOI: 10.5551/jat.39917] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Aim: Research shows that subclinical hypothyroidism (SCH) is related to an increased carotid intima –media thickness (CIMT), a surrogate marker of subclinical cardiovascular disease (CVD). It is controversial whether or not SCH should be treated to reduce CVD morbidity and mortality. This meta-analysis aimed to determine whether SCH is associated with an increase in CIMT as compared to Euthyroidism (EU) and whether thyroxin (T4) treatment in SCH can reverse the change in CIMT. Methods: Two independent reviewers conducted an extensive database research up to December 2016. A total of 12 clinical trials discussed the effect of Thyroxin on CIMT values at pre- and post-treatment in subjects with SCH. Results: CIMT was significantly higher among SCH (n = 280) as compared to EU controls (n = 263) at baseline; the pooled weighted mean difference (WMD) of CIMT was 0.44 mm [95% confidence interval (CI) 0.14, 0.74], p = 0.004; I2 = 65%. After treatment with thyroxin in subjects with SCH (n = 314), there was a statistically significant decrease in CIMT from pre- to post-treatment; the pooled WMD of CIMT decrease was [WMD −0.32; 95% CI (−0.47, −0.16), p = < 0.0001; I2 = 2%], and it was no longer different from EU controls [WMD 0.13 mm; 95% CI (−0.04, 0.30); p = 0.14; I2 = 27%]. The total cholesterol (TC), triglycerides (TG), and low-density lipoprotein (LDL) were higher in SCH as compared to EU controls and decreased significantly after treatment with thyroxin. Conclusion: This meta-analysis shows that thyroxin therapy in subjects with SCH significantly decreases CIMT and improves lipid profile, modifiable CVD risk factors. Thyroid hormone replacement in subjects with SCH may play a role in slowing down or preventing the progression of atherosclerosis.
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Quan X, Ji Y, Zhang C, Guo X, Zhang Y, Jia S, Ma W, Fan Y, Wang C. Circulating MiR-146a May be a Potential Biomarker of Coronary Heart Disease in Patients with Subclinical Hypothyroidism. Cell Physiol Biochem 2018; 45:226-236. [PMID: 29357324 DOI: 10.1159/000486769] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 10/13/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Subclinical hypothyroidism (SCH) plays a crucial role in the development and progression of coronary heart disease (CHD). However, any associated changes in the circulating microRNAs (miRNAs) levels and slightly elevated thyroid stimulating hormone (TSH) levels in CHD patients are unknown. miR-146a is a well known miRNA associated with inflammatory autoimmune diseases. Here, we evaluated miR-146a expression in patients, with the goal of re-evaluating the effect of SCH on CHD. METHODS A total of 192 study subjects who underwent coronary angiography for either suspected or confirmed CHD were enrolled in 3 groups: CHD with SCH, CHD alone, and healthy controls. The circulating levels of miR-146a were quantified using qRT-PCR. RESULTS Levels of miR-146a were positively correlated with CHD severity, as indicated by the Gensini score (r=0.354). The relative expression of miR-146a in the CHD+SCH, CHD and healthy control groups was 2.223±0.827, 1.588±0.726 and 0.632±0.309, respectively. Plasma TSH levels were positively correlated with miR-146a levels (r=0.321). According to multivariate logistic regression analyses, miR-146a levels were associated with the incidence of CHD in patients with SCH. For diagnosing CHD, the area under the ROC curve (AUC) of miR-146a and TSH was 0.779 and 0.752, respectively. When the TSH and miR-146a levels were combined to form a composite panel, the AUC of the panel was 0.858. CONCLUSION Plasma miR-146a levels correlated with the severity of coronary atherosclerosis and increased with TSH slightly elevated in patients with CHD. Thus, miR-146a may have good predictive value for CHD among individuals with elevated TSH levels.
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Rao M, Zeng Z, Zhao S, Tang L. Effect of levothyroxine supplementation on pregnancy outcomes in women with subclinical hypothyroidism and thyroid autoimmuneity undergoing in vitro fertilization/intracytoplasmic sperm injection: an updated meta-analysis of randomized controlled trials. Reprod Biol Endocrinol 2018; 16:92. [PMID: 30249251 PMCID: PMC6154908 DOI: 10.1186/s12958-018-0410-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Accepted: 09/14/2018] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Evidence suggests that subclinical hypothyroidism (SCH) and thyroid autoimmunity (TAI) are associated with adverse pregnancy outcomes. This systematic review and meta-analysis was conducted to determine whether levothyroxine (LT4) supplementation would improve pregnancy outcomes among infertile women with SCH and/or TAI who underwent in vitro fertilization (IVF) or intracytoplastic sperm injection (ICSI). METHODS We searched databases of PubMed, EMBASE, Web of Science, Cochrane Controlled Trials Register databases, and Clinicaltrials.gov up to April 2018 to identify eligible studies. Studies that focused on the treatment effect of LT4 on pregnancy outcomes of women with SCH and/or TAI who underwent IVF/ICSI were included in the data synthesis. We only included randomized controlled trials (RCTs). Relative risks (RR) and 95% confidence intervals (CI) were calculated using a random-effects model to assess the results of pregnancy outcomes, including clinical pregnancy rate, miscarriage rate, live birth rate and preterm birth rate. RESULTS Four published RCTs including 787 infertile couples undergoing IVF/ICSI were included in this meta-analysis. Notably, the study observed no significant associations of LT4 treatment with the clinical pregnancy rate (RR = 1.46, 95% CI: 0.86-2.48), live birth rate (RR = 2.05, 95% CI: 0.96-4.36), or preterm birth rate (RR = 1.13, 95% CI: 0.65-1.96). However, patients receiving LT4 supplementation had a significantly decreased miscarriage rate relative to those receiving a placebo or no treatment (RR = 0.51, 95% CI: 0.32-0.82). A further sub-group analysis showed that LT4 supplementation did not improve the miscarriage rates among patients with SCH (RR = 0.67, 95% CI: 0.39-1.15) or TAI (RR = 0.28, 95% CI: 0.07-1.06). CONCLUSIONS Given its potential to reduce the miscarriage rate, LT4 supplementation is recommended for infertile women with SCH and/or TAI who are undergoing IVF/ICSI. However, additional population-based RCTs are needed to confirm this recommendation.
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Meta-Analysis |
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Grossman A, Weiss A, Koren-Morag N, Shimon I, Beloosesky Y, Meyerovitch J. Subclinical Thyroid Disease and Mortality in the Elderly: A Retrospective Cohort Study. Am J Med 2016; 129:423-30. [PMID: 26714213 DOI: 10.1016/j.amjmed.2015.11.027] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 10/31/2015] [Accepted: 11/29/2015] [Indexed: 01/07/2023]
Abstract
OBJECTIVE The association between subclinical hypothyroidism and hyperthyroidism and mortality in the elderly is poorly defined. This study was designed to evaluate the association between subclinical hypothyroidism and subclinical hyperthyroidism and mortality in the elderly and to define the thyroid-stimulating hormone values associated with excess mortality in the elderly. METHODS We performed a retrospective cohort study with a review of a computerized database of a large health care organization. Patients aged more than 65 years evaluated in the years 2002 to 2012 with documented normal free T4 values were included in the analysis. All cases of known thyroid disease or cases in which thyroid medications were dispensed were excluded. Analysis was performed only on individuals who were not treated for hyperthyroidism or hypothyroidism during the follow-up period. Subjects were divided into 3 groups based on thyroid-stimulating hormone values: normal (normal thyroid-stimulating hormone), subclinical hypothyroidism (thyroid-stimulating hormone >4.2 mIU/L), and subclinical hyperthyroidism (thyroid-stimulating hormone <0.35 mIU/L). All-cause mortality hazard ratio (HR) was compared among the 3 groups, and a subanalysis according to thyroid-stimulating hormone values was performed in those with subclinical hypothyroidism and subclinical hyperthyroidism. RESULTS A final analysis was performed on 17,440 individuals with subclinical thyroid disease (538 with subclinical hyperthyroidism [3.1%], 1956 with subclinical hypothyroidism [11.2%], 14,946 normal cases [85.7%], average age of 83 years, 10,289 were women) who were followed up for 10 years. Both subclinical hypothyroidism (HR, 1.75; confidence interval [CI], 1.63-1.88) and subclinical hyperthyroidism (HR, 2.33; CI, 2.08-2.63) were associated with significantly increased mortality, and this association persisted on multivariate analysis (subclinical hypothyroidism HR, 1.68; CI, 1.56-1.8, subclinical hyperthyroidism HR, 1.93; CI, 1.7-2.17). Crude mortality was elevated at 1, 2, and 5 years, but this association seemed to decrease as time from initial analysis increased (most significant association at 1 year). Thyroid-stimulating hormone values greater than 6.38 mIU/L were associated with the highest mortality in those with subclinical hypothyroidism after multivariate adjustment (HR, 1.708; CI, 1.38-2.12), whereas in subclinical hyperthyroidism, no threshold for increased mortality was identified. Mortality was higher. CONCLUSIONS Both subclinical hypothyroidism and subclinical hyperthyroidism are associated with increased mortality in the elderly. A threshold thyroid-stimulating hormone value (>6.35 mIU/L) exists for increased mortality in subclinical hypothyroidism, but not in subclinical hyperthyroidism.
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Subclinical thyroid dysfunction is associated with adverse prognosis in heart failure patients with reduced ejection fraction. BMC Cardiovasc Disord 2019; 19:83. [PMID: 30947691 PMCID: PMC6450005 DOI: 10.1186/s12872-019-1055-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 03/20/2019] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Subclinical thyroid dysfunction whose typical patterns include subclinical hypothyroidism and subclinical hyperthyroidism, has been indicated to be associated with an increased risk of heart failure (HF). However, the relationship between subclinical thyroid dysfunction and the clinical outcomes of HF patients is uncertain. This meta-analysis was conducted to assess the association between subclinical thyroid dysfunction and the clinical outcomes of HF patients. METHODS Pubmed, Embase, Web of Science and Cochrane Central Register of Clinical Trials were searched for eligible studies published up to August 1, 2018 which reported the association between subclinical thyroid dysfunction and the clinical outcomes of HF patients. The pooled hazard ratio (HR) with the corresponding 95% confidence interval (CI) was used to assess the association. RESULTS Fourteen studies met the eligibility criteria and a total of 21,221 patients with heart failure were included in the meta-analysis. Compared with HF patients with euthyroidism, the pooled HR of subclinical hypothyroidism for all-cause mortality was 1.45 (95% CI 1.26-1.67) in a randomized effects model with mild heterogeneity (I2 = 40.1, P = 0.073). The pooled HR of subclinical hypothyroidism for cardiac death and/or hospitalization was 1.33 (1.17-1.50) in a randomized effects model with moderate heterogeneity (I2 = 69.4, P < 0.001). Subclinical hyperthyroid can increase the risk of all-cause mortality without heterogeneity (HR 1.31, 95% CI 1.10-1.55, I2 = 25.5%, P = 0.225) but have no influence on the risk of cardiac death and/or hospitalization (HR 1.03, 95% CI 0.87-1.23, I2 = 0.0%, P = 0.958). These significant adverse associations were also retained in subgroup analysis. Sensitivity analysis demonstrated the stability of the results of our meta-analysis. CONCLUSIONS Both subclinical hypothyroidism and subclinical hyperthyroidism are associated with adverse prognosis in patients with HF. Subclinical thyroid dysfunction may be a useful and promising predictor for the long-term prognosis in HF patients.
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Review |
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Gong Y, Ma Y, Ye Z, Fu Z, Yang P, Gao B, Guo W, Hu D, Ye J, Ma S, Zhang F, Zhou L, Xu X, Li Z, Yang T, Zhou H. Thyroid stimulating hormone exhibits the impact on LDLR/LDL-c via up-regulating hepatic PCSK9 expression. Metabolism 2017; 76:32-41. [PMID: 28987238 DOI: 10.1016/j.metabol.2017.07.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 07/12/2017] [Accepted: 07/19/2017] [Indexed: 12/20/2022]
Abstract
CONTEXT Thyroid stimulating hormone (TSH) has received increasing attention as being closely associated with increased low-density lipoprotein cholesterol (LDL-c) level and higher atherosclerotic risks. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is known for increasing circulating LDL-c level by inducing LDL receptor degradation. However, whether TSH influences hepatic PCSK9 expression and LDL-c metabolism remains unclear. METHODS First, the correlation between TSH and lipid profiles were investigated in euthyroid population and in subclinical hypothyroidism patients. Then, an in vitro study was conducted to validate the effects of TSH on hepatic PCSK9 expression in HepG2 cells. RESULTS Serum TSH concentrations positively correlated with LDL-c levels in euthyroid subjects. Subclinical hypothyroidism patients with higher serum TSH levels showed significantly increased serum PCSK9 levels than the matched euthyroid participants (151.29 (89.51-293.03) vs. 84.70 (34.98-141.72) ng/ml, P<0.001), along with increased LDL-c concentrations. In HepG2 cells, LDLR expression on the plasma membrane was decreased, and PCSK9 mRNA and protein levels were synchronously upregulated after recombinant human TSH (rhTSH) treatment, while the effects could be blocked by TSH receptor blocking antibody K1-70. Sterol regulatory element binding protein (SREBP) 1c and SREBP2 mRNA expressions were enhanced after rhTSH treatment, and specific siRNAs significantly inhibited the effects of rhTSH. Furthermore, there was a noticeable induction of PCSK9 expression by rhTSH even though HMGCR gene expression was silenced. CONCLUSION We conclude a regulating role of TSH on hepatic PCSK9 expression, which further contributing to a higher LDL-c level.
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Stott DJ, Gussekloo J, Kearney PM, Rodondi N, Westendorp RGJ, Mooijaart S, Kean S, Quinn TJ, Sattar N, Hendry K, Du Puy R, Den Elzen WPJ, Poortvliet RKE, Smit JWA, Jukema JW, Dekkers OM, Blum M, Collet TH, McCarthy V, Hurley C, Byrne S, Browne J, Watt T, Bauer D, Ford I. Study protocol; Thyroid hormone Replacement for Untreated older adults with Subclinical hypothyroidism - a randomised placebo controlled Trial (TRUST). BMC Endocr Disord 2017; 17:6. [PMID: 28158982 PMCID: PMC5291970 DOI: 10.1186/s12902-017-0156-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Accepted: 01/27/2017] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Subclinical hypothyroidism (SCH) is a common condition in elderly people, defined as elevated serum thyroid-stimulating hormone (TSH) with normal circulating free thyroxine (fT4). Evidence is lacking about the effect of thyroid hormone treatment. We describe the protocol of a large randomised controlled trial (RCT) of Levothyroxine treatment for SCH. METHODS Participants are community-dwelling subjects aged ≥65 years with SCH, diagnosed by elevated TSH levels (≥4.6 and ≤19.9 mU/L) on a minimum of two measures ≥ three months apart, with fT4 levels within laboratory reference range. The study is a randomised double-blind placebo-controlled parallel group trial, starting with levothyroxine 50 micrograms daily (25 micrograms in subjects <50Kg body weight or known coronary heart disease) with titration of dose in the active treatment group according to TSH level, and a mock titration in the placebo group. The primary outcomes are changes in two domains (hypothyroid symptoms and fatigue / vitality) on the thyroid-related quality of life questionnaire (ThyPRO) at one year. The study has 80% power (at p = 0.025, 2-tailed) to detect a change with levothyroxine treatment of 3.0% on the hypothyroid scale and 4.1% on the fatigue / vitality scale with a total target sample size of 750 patients. Secondary outcomes include general health-related quality of life (EuroQol), fatal and non-fatal cardiovascular events, handgrip strength, executive cognitive function (Letter Digit Coding Test), basic and instrumental activities of daily living, haemoglobin, blood pressure, weight, body mass index and waist circumference. Patients are monitored for specific adverse events of interest including incident atrial fibrillation, heart failure and bone fracture. DISCUSSION This large multicentre RCT of levothyroxine treatment of subclinical hypothyroidism is powered to detect clinically relevant change in symptoms / quality of life and is likely to be highly influential in guiding treatment of this common condition. TRIAL REGISTRATION Clinicaltrials.gov NCT01660126 ; registered 8th June 2012.
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Randomized Controlled Trial |
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Moon SH, Lee BJ, Kim SJ, Kim HC. Relationship between thyroid stimulating hormone and night shift work. Ann Occup Environ Med 2016; 28:53. [PMID: 27761265 PMCID: PMC5054581 DOI: 10.1186/s40557-016-0141-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 09/28/2016] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Night shift work has well-known adverse effects on health. However, few studies have investigated the relationship between thyroid diseases and night shift work. This study aimed to examine night shift workers and their changes in thyroid stimulating hormones (TSH) levels over time. METHODS Medical check-up data (2011-2015) were obtained from 967 female workers at a university hospital in Incheon, Korea. Data regarding TSH levels were extracted from the records, and 2015 was used as a reference point to determine night shift work status. The relationships between TSH levels and night shift work in each year were analyzed using the general linear model (GLM). The generalized estimating equation (GEE) was used to evaluate the repeated measurements over the 5-year period. RESULTS The GEE analysis revealed that from 2011 to 2015, night shift workers had TSH levels that were 0.303 mIU/L higher than the levels of non-night shift workers (95 % CI: 0.087-0.519 mIU/L, p = 0.006) after adjusting for age and department. When we used TSH levels of 4.5 ≥ mIU/L to identify subclinical hypothyroidism, night shift workers exhibited a 1.399 fold higher risk of subclinical hypothyroidism (95 % CI: 1.050-1.863, p = 0.022), compared to their non-night shift counterparts. CONCLUSIONS This result of this study suggests that night shift workers may have an increased risk of thyroid diseases, compared to non-night shift workers.
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Yang L, Lv X, Yue F, Wei D, Liu W, Zhang T. Subclinical hypothyroidism and the risk of metabolic syndrome: A meta-analysis of observational studies. Endocr Res 2016; 41:158-65. [PMID: 26934475 DOI: 10.3109/07435800.2015.1108332] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Observational studies on the association between subclinical hypothyroidism (SCH) and metabolic syndrome (MetS) have produced inconsistent results. Therefore, we performed a meta-analysis to evaluate the effect of SCH on the risk of MetS. METHODS Multiple databases were searched to identify studies on the association between SCH and the risk of MetS, up to February 2015. Relevant information for analysis was extracted. A random-effects model was used to calculate the pooled risk estimates. RESULTS 9 studies (7 cross-sectional and 2 case-control studies) were included. The pooled odds ratio (OR) for MetS comparing SCH with euthyroid subjects was 1.31 (95%CI: 1.08 to 1.60, p = 0.006, I(2) = 50%). Subgroup analyses by countries revealed a significant association for the studies from Asian (OR = 1.244, 95% CI: 1.030-1.503, I(2) = 25%) other than non-Asian (OR = 1.548, 95% CI: 0.925-2.591, I(2) = 73.5%) countries. A positive association was identified in the IDF subgroup (OR = 1.288, 95% CI: 1.055-1.572, I(2) = 0%), but not in the NCEP-ATP III (OR = 1.351, 95% CI: 0.950-1.923, I(2) = 66.4%), Chinese (OR = 1.430, 95% CI: 0.891-2.294) and Japanese (OR = 1.542, 95% CI: 0.594-4.005, I(2) = 78.3%) subgroup. A certain degree of heterogeneity was observed among studies which cannot be explained by study design, diagnostic criteria and location. CONCLUSION Our results demonstrated that SCH was significantly associated with a higher risk of MetS. Well-designed cohort studies were warranted to confirm our findings.
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Meta-Analysis |
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Bielecka-Dabrowa A, Godoy B, Suzuki T, Banach M, von Haehling S. Subclinical hypothyroidism and the development of heart failure: an overview of risk and effects on cardiac function. Clin Res Cardiol 2018; 108:225-233. [PMID: 30091084 DOI: 10.1007/s00392-018-1340-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 07/18/2018] [Indexed: 01/07/2023]
Abstract
The prevalence of subclinical hypothyroidism (SCH) ranges from 5 to 15% of the general population. However, it remains controversial if SCH warrants life-long thyroxine replacement therapy. Patients with a thyroid-stimulating hormone (TSH) level > 10 mIU/L have a higher risk of developing heart failure with reduced ejection fraction as compared to subjects with normal thyroid function. However, abnormally high TSH levels could also be connected with an overall lower metabolic rate and better survival in elderly subjects. The potential mechanisms responsible for diastolic dysfunction of the left ventricle (LV) in SCH are connected with endothelial dysfunction and arterial stiffness, inflammatory state and are driven by TSH apoptosis-derived microparticles. The impact of SCH on LV systolic function is more controversial, and it is connected not only with cardiac remodelling but also with predisposition of patients with SCH to the conditions leading to heart failure. This review presents an overview of processes in the context of potential benefits of thyroxine supplementation therapy.
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Review |
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Jia M, Wu Y, Lin B, Shi Y, Zhang Q, Lin Y, Wang S, Zhang Y. Meta-analysis of the association between maternal subclinical hypothyroidism and gestational diabetes mellitus. Int J Gynaecol Obstet 2019; 144:239-247. [PMID: 30578669 DOI: 10.1002/ijgo.12751] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Revised: 08/02/2018] [Accepted: 12/20/2018] [Indexed: 11/09/2022]
Abstract
BACKGROUND Subclinical hypothyroidism (SCH) and gestational diabetes mellitus (GDM) are common endocrine disorders that occur during pregnancy. OBJECTIVE To determine whether the risk of GDM differs between pregnant women with normal thyroid function and those with SCH. SEARCH STRATEGY MEDLINE, EMBASE, the Cochrane Library, and Web of Science were searched for studies published in English from inception to March 1, 2017, using combinations of the search terms "thyroid dysfunction", "thyroid diseases", "subclinical hypothyroidism", "hypothyroxinemia", "thyrotropin", "gestational diabetes", "hyperglycemia in pregnancy", and "adverse pregnancy outcomes". SELECTION CRITERIA We selected cohort studies that included pregnant women with SCH; in which the outcome of interest was, or included, the incidence of GDM; and that had data available for both the SCH and GDM groups. Studies were excluded if assisted reproductive technologies were used to achieve pregnancy; reviews, abstracts, and case reports were also excluded. DATA COLLECTION AND ANALYSIS Eleven studies were included in the analysis. Summary odds ratios (ORs) for the risk of GDM were calculated. MAIN RESULTS SCH with positive antithyroid autoantibodies markedly increased GDM risk (OR 3.22, 95% confidence interval 1.72-6.03, I2 =55%). CONCLUSION SCH with positive antithyroid autoantibodies in pregnancy is associated with an increased risk of GDM.
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Meta-Analysis |
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Gencer B, Moutzouri E, Blum MR, Feller M, Collet TH, Delgiovane C, da Costa BR, Buffle E, Monney P, Gabus V, Müller H, Sykiotis GP, Kearney P, Gussekloo J, Westendorp R, Stott DJ, Bauer DC, Rodondi N. The Impact of Levothyroxine on Cardiac Function in Older Adults With Mild Subclinical Hypothyroidism: A Randomized Clinical Trial. Am J Med 2020; 133:848-856.e5. [PMID: 32171774 DOI: 10.1016/j.amjmed.2020.01.018] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 12/29/2019] [Accepted: 01/08/2020] [Indexed: 12/15/2022]
Abstract
BACKGROUND Subclinical hypothyroidism has been associated with heart failure, but only small trials assessed whether treatment with levothyroxine has an impact on cardiac function. METHODS In a randomized, double-blind, placebo-controlled, trial nested within the TRUST trial, Swiss participants ages ≥65 years with subclinical hypothyroidism (thyroid-stimulating hormone [TSH] 4.60-19.99 mIU/L; free thyroxine level within reference range) were randomized to levothyroxine (starting dose of 50 µg daily) to achieve TSH normalization or placebo. The primary outcomes were the left ventricular ejection fraction for systolic function and the ratio between mitral peak velocity of early filling to early diastolic mitral annular velocity (E/e' ratio) for diastolic function. Secondary outcomes included e' lateral/septal, left atrial volume index, and systolic pulmonary artery pressure. RESULTS A total of 185 participants (mean age 74.1 years, 47% women) underwent echocardiography at the end of the trial. After a median treatment duration of 18.4 months, the mean TSH decreased from 6.35 mIU/L to 3.55 mIU/L with levothyroxine (n = 96), and it remained elevated at 5.29 mIU/L with placebo (n = 89). The adjusted between-group difference was not significant for the mean left ventricular ejection fraction (62.7% vs 62.5%, difference = 0.4%, 95% confidence interval -1.8% to 2.5%, P = 0.72) and the E/e' ratio (10.6 vs 10.1, difference 0.4, 95% confidence interval -0.7 to 1.4, P = 0.47). No differences were found for the secondary diastolic function parameters or for interaction according to sex, baseline TSH, preexisting heart failure, and treatment duration (P value >0.05). CONCLUSION Systolic and diastolic heart function did not differ after treatment with levothyroxine compared with placebo in older adults with mild subclinical hypothyroidism.
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Gyawali P, Takanche JS, Shrestha RK, Bhattarai P, Khanal K, Risal P, Koju R. Pattern of thyroid dysfunction in patients with metabolic syndrome and its relationship with components of metabolic syndrome. Diabetes Metab J 2015; 39:66-73. [PMID: 25729715 PMCID: PMC4342539 DOI: 10.4093/dmj.2015.39.1.66] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2014] [Accepted: 10/31/2014] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Thyroid dysfunction (TD) and metabolic syndrome (MetS) are known risk factors for atherosclerotic cardiovascular disease (ASCVD). TD is risk factor for ASCVD mediated by the effects of thyroid hormones on lipid metabolism and blood pressure hence the components of MetS. It is possible that coexistence of these two disease entities and unrecognized TD in patients with MetS might substantially increase ASCVD risk. Moreover, little is known about the relationship between TD and the components of MetS. Thus, the purpose of this study was to evaluate the pattern of TD in patients with MetS and its relationship with components of the MetS. METHODS A total of 358 previously diagnosed patients with MetS were recruited in the study. The thyroid function test parameters were measured to classify TD at Dhulikhel Hospital-Kathmandu University Hospital, Dhulikhel, Nepal. Statistical analyses were performed using SPSS version 16.0 to evaluate pattern and relationship. RESULTS The overall prevalence of TD in patients with MetS was 31.84% with high prevalence of subclinical hypothyroidism (29.32%). We found no evidence of a relationship between TD and components of MetS, although there was significant difference in waist circumference between four groups of TD. CONCLUSION Patients with MetS had subclinical hypothyroidism greatly. Although there was no evidence of any relationship between thyroid status and all components of MetS, TD should be taken into account when evaluating and treating patients with MetS to reduce the impending risk.
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Sharma LK, Sharma N, Gadpayle AK, Dutta D. Prevalence and predictors of hyperprolactinemia in subclinical hypothyroidism. Eur J Intern Med 2016; 35:106-110. [PMID: 27473607 DOI: 10.1016/j.ejim.2016.07.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 07/06/2016] [Accepted: 07/07/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND AND AIMS Hyperprolactinemia has been reported in 0-57% of primary hypothyroidism. Data on hyperprolactinemia in subclinical hypothyroidism (ScH) is scant and inconsistent. This study aimed to determine the prevalence and predictors of hyperprolactinemia in ScH. METHODS Consecutive patients diagnosed to have normal thyroid function, ScH or overt primary hypothyroidism underwent serum prolactin, gonadotropins, testosterone and estradiol estimation. Patients with pregnancy, pituitary adenomas, secondary hypothyroidism, hyperthyroidism, comorbid states and drug-induced hyperprolactinemia were excluded. RESULTS From initially screened 4950 patients, hormonal data from 2848 individuals who fulfilled all criteria were analyzed. The occurrence of hyperprolactinemia (females:males) was highest in primary hypothyroidism (42.95%:39.53%) (n=192), followed by ScH (35.65%:31.61%) (n=770) and euthyroid individuals (2.32%:2.02%) (n=1886) (P<0.001). Hyperprolactinemia in ScH with TSH 5-7.5, 7.5-10 and >10mIU/L (females: males) was 25.56%:20.73%, 49.07%:50% and 61.43%:35.71% respectively (P<0.001). Significant positive correlation between TSH and prolactin was noted in ScH and primary hypothyroidism. In females, testosterone was lowest in patients with primary hypothyroidism. In males, serum estradiol was significantly higher, and testosterone significantly lower in men with ScH and primary hypothyroidism. Regression analysis revealed serum TSH followed by free T4, to be best predictors of serum prolactin in both sexes. CONCLUSION Hyperprolactinemia is common in ScH, especially in those with TSH>7.5mIU/L. ROC analysis confirmed that TSH≥7.51mIU/L in females and ≥8.33mIU/L in males had a sensitivity of ≈50% with a very high specificity of >90% in detecting hyperprolactinemia. Prolactin screening may be warranted in ScH with TSH>7.5mIU/L, and may form an indication for treating ScH.
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Abstract
Overt hypothyroidism and thyrotoxicosis are associated with significant decrements in mood and cognitive function, and therapy usually leads to improvement in these symptoms. In contrast, major affective or cognitive dysfunction is not typical of subclinical thyroid disease. Subtle deficits in specific cognitive domains (primarily working memory and executive function) likely exist in subclinical hypothyroidism and thyrotoxicosis, but these are unlikely to cause major problems in most patients. Patients with mild thyroid disease and significant distress related to mood or cognition most likely have independent diagnoses that should be evaluated and treated separately.
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Review |
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Mahadik K, Choudhary P, Roy PK. Study of thyroid function in pregnancy, its feto-maternal outcome; a prospective observational study. BMC Pregnancy Childbirth 2020; 20:769. [PMID: 33302910 PMCID: PMC7726876 DOI: 10.1186/s12884-020-03448-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Accepted: 11/22/2020] [Indexed: 12/13/2022] Open
Abstract
Background Pregnancy is a stress test of maternal thyroid function. The prevalence of thyroid dysfunction in pregnant women is high. Subclinical hypothyroidism occurs in 10% of all pregnancies. Effects of hypothyroidism in pregnancy are anemia, low birth weight and mental retardation in neonate. This study is aimed to evaluate maternal and fetal outcomes in pregnant women with deranged thyroid profile. The relevance of this study is to document the association of hypothyroidism and its adverse effects on mother and fetus. Methods This prospective observational study was carried out at R.D. Gardi Medical College, Ujjain, India. Subjects of this study were 198 antenatal women in third trimester with singleton pregnancy admitted in the obstetric ward, and informed consent was obtained. Women were chosen irrespective of age, parity, residence and socioeconomic status. Women with multiple pregnancy, a known case of thyroid disorder, or any pre-existing medical disorder were excluded. Routine hematological parameters and estimation of T3, T4 and TSH was conducted. Patients with deranged thyroid profile were subsequently assessed for maternal and fetal complications. History of infertility, family history of thyroid disease, menstrual pattern, recurrent abortion, hemoglobin level and fetal outcome were the main study variables. Data was analysed in SPSS software for statistical co-relation. Results Prevalence of thyroid disorder is 11%; with subclinical hypothyroidism, overt hypothyroidism and subclinical hyperthyroidism occurring in 5.6, 3.5 and 1.5% of subjects respectively. In women with subclinical and overt hypothyroidism, anemia was present in 26.3% being significantly associated with hypothyroidism (p = 0.008). With respect to fetal outcome, LBW 31.6% (p = 0.001), NICU admission 42.1%, (p = 0.000) and low APGAR Score (21.1%, p = 0.042) were statistically associated with hypothyroidism. Risk of anemia, Low Birth weight, NICU admissions, and low APGAR score was 4.8, 6.3, 0.14 and 3.64 times higher respectively in women with hypothyroidism than in women who are euthyroid. Conclusion Prevalence of subclinical hypothyroidism is 5.6% in 3rd trimester of pregnancy. Anemia, pre-eclampsia, high caesarean rates and neonatal morbidities is significantly associated with hypothyroidism.
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Observational Study |
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Stratigou T, Dalamaga M, Antonakos G, Marinou I, Vogiatzakis E, Christodoulatos GS, Karampela I, Papavassiliou AG. Hyperirisinemia is independently associated with subclinical hypothyroidism: correlations with cardiometabolic biomarkers and risk factors. Endocrine 2018; 61:83-93. [PMID: 29455364 DOI: 10.1007/s12020-018-1550-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 01/29/2018] [Indexed: 12/17/2022]
Abstract
PURPOSE Irisin, a newly discovered adipo-myokine, is implicated in the modulation of the adipose phenotype, increasing energy expenditure and ameliorating systemic metabolism. Our aim was to investigate circulating irisin in subclinical hypothyroidism (SH) and study its associations with cardiometabolic risk factors. METHODS In a large case-control study, serum irisin, insulin resistance and lipid parameters, classic adipokines, inflammatory and hepatic biomarkers, and cardiovascular risk factors were determined in 120 consecutive patients with SH and 120 healthy controls matched on age, gender, and date of blood draw. Sixteen patients with SH received L-T4 treatment and, after 6 months, serum irisin and other biomarkers were assessed. RESULTS SH cases exhibited significantly higher circulating irisin than controls (p < 0.001). In all participants, irisin was positively associated with TSH, anti-TG, HOMA-IR, C-peptide, lipid and inflammatory biomarkers, leptin, and cardiovascular risk factors, including Framigham score and apolipoprotein B/apolipoprotein A-I. Irisin was negatively correlated with adiponectin, HDL-C, and thyroid hormones. Serum irisin was independently associated with SH, above and beyond body mass index and cardiometabolic factors (p = 0.02). TSH was an independent predictor of circulating irisin (p = 0.003). L-T4 therapy did not reverse considerably the hyperirisinemic status in treated SH patients (p = 0.09). CONCLUSIONS Irisin may represent an adipo-myokine counterbalancing a potential, gradual deterioration of lipid metabolism and insulin sensitivity in SH as well as reflecting a protective compensatory mechanism against oxidative muscle and thyroid cell stress. More mechanistic and prospective studies shedding light on the pathogenetic role of irisin in SH are needed to confirm and extend these data.
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Peixoto de Miranda ÉJF, Bittencourt MS, Pereira AC, Goulart AC, Santos IS, Lotufo PA, Bensenor IM. Subclinical hypothyroidism is associated with higher carotid intima-media thickness in cross-sectional analysis of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Nutr Metab Cardiovasc Dis 2016; 26:915-921. [PMID: 27389191 DOI: 10.1016/j.numecd.2016.06.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 06/10/2016] [Accepted: 06/11/2016] [Indexed: 12/24/2022]
Abstract
BACKGROUND AND AIM Although subclinical hypothyroidism (SCH) is associated with cardiovascular risk, there is scarce data about subclinical atherosclerosis in subjects with SCH. We aimed to analyze the association between SCH and carotid intima-media thickness (IMT) using baseline data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). METHODS AND RESULTS We included subjects with normal thyroid function (TSH: 0.4-4.0 mIU/l, and normal free thyroxine (FT4): 0.8-1.9 ng/dl) and SCH (TSH ≥ 4.0 mIU/l and normal FT4) evaluated for IMT in a cross-sectional analysis. We excluded individuals using medications that affect thyroid function and those with a history of cardiovascular disease. We performed logistic and linear regression models to evaluate the association with IMT (mean values and categorized at the 75th percentile) as a dependent variable and SCH as an independent variable, adjusted for other cardiovascular risk factors. From 8623 subjects (median age of 50 years; interquartile range: 44-57), 4624 (53.6%) were women, 8095 (93.9%) were euthyroid, and 528 (6.1%) had SCH. Groups varied in age, body mass index, Framingham risk score, Homeostasis Model Assessment for Insulin Resistance (HOMA-IR), C-reactive protein, as well as, IMT, that were all higher in SCH compared to euthyroid participants. SCH is associated with IMT as a continuous variable (β = 0.010, P = 0.036) and IMT >75th percentile: OR = 1.30 (95% CI = 1.06-1.59) in logistic models. CONCLUSION Individuals with SCH presented higher IMT compared with euthyroid subjects, even after adjustment for potential confounders. IMT was independently associated with SCH in the baseline of the ELSA-Brasil study.
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Multicenter Study |
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Khatiwada S, Sah SK, Kc R, Baral N, Lamsal M. Thyroid dysfunction in metabolic syndrome patients and its relationship with components of metabolic syndrome. Clin Diabetes Endocrinol 2016; 2:3. [PMID: 28702239 PMCID: PMC5471726 DOI: 10.1186/s40842-016-0021-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Accepted: 01/10/2016] [Indexed: 11/16/2022] Open
Abstract
Background A growing body of evidence suggests that metabolic syndrome is associated with endocrine disorders including thyroid dysfunction. Thyroid dysfunction in metabolic syndrome patients may further add to cardiovascular disease risk thereby increasing mortality. This study was done to assess thyroid function in metabolic syndrome patients and evaluate its relationship with the components of metabolic syndrome. Methods A cross sectional study was carried out among 169 metabolic syndrome patients at B P Koirala Institute of Health Sciences, Dharan, Nepal. Anthropometric measurements (height, weight, waist circumference) and blood pressure were taken. Fasting blood samples were analysed to measure glucose, triglyceride, high density lipoprotein (HDL) cholesterol and thyroid hormones (triiodothyronine, thyroxine and thyroid stimulating hormone). Results Thyroid dysfunction was seen in 31.9 % (n = 54) metabolic syndrome patients. Subclinical hypothyroidism (26.6 %) was the major thyroid dysfunction followed by overt hypothyroidism (3.5 %) and subclinical hyperthyroidism (1.7 %). Thyroid dysfunction was much common in females (39.7 %, n = 29) than males (26 %, n = 25) but not statistically significant (p = 0.068). The relative risk of having thyroid dysfunction in females was 1.525 (CI: 0.983–2.368) as compared to males. Significant differences (p = 0.001) were observed in waist circumference between patients with and without thyroid dysfunction and HDL cholesterol which had significant negative correlation with thyroid stimulating hormone. Conclusions Thyroid dysfunction, particularly subclinical hypothyroidism is common among metabolic syndrome patients, and is associated with some components of metabolic syndrome (waist circumference and HDL cholesterol).
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Journal Article |
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