Thyroid disease and the heart

A systematic review of the clinical characteristics and course of atrioventricular blocks in hyperthyroidism

BACKGROUND

Atrioventricular block (AVB) is rare in hyperthyroidism (HTH). Little is known about the true prevalence, clinical course, optimal management, and outcomes of different types of AVBs in patients with HTH. To address these uncertainties, we aimed to conduct a systematic review by combining the available literature to provide more meaningful data regarding AVBs in HTH.

METHODS

We systematically searched PubMed, Scopus, Embase, and Google Scholar for articles reporting patients who developed AVB in the context of HTH. Data were analysed in STATA 16. The main outcomes included types of AVB, frequency of pacemaker insertion, and resolution of AVB. The systematic review is registered with the International Prospective Register of Systematic Reviews (PROSPERO) with the identification number CRD42022335598.

RESULTS

A total of 56 studies (39 case reports, 12 case series, 3 conference abstracts, 1 retrospective study, and 1 prospective observational study) with 87 patients were included in the analysis, with a mean age of 39.1 ± 17.6 years. Females constituted 65.7% (n = 48) of the cohort. Complete heart block (CHB) was the most commonly reported AVB (N = 45, 51.7%), followed by first-degree AVB (16.1%) and second-degree AVB (14.9%). Overall, 21 patients underwent pacing. A permanent pacemaker was inserted in one patient with second-degree AVB and six patients with CHB. Mortality was reported in one patient with CHB. The clinical course and management of HTH and AVBs did not differ in patients with CHB or lower-degree blocks. Apart from lower rates of goitre and more use of carbimazole in those who underwent pacing, no differences were found when compared to the patients managed without pacing.

CONCLUSION

Current data suggest that CHB is the most common type of AVB in patients with HTH. Most patients can be managed with anti-thyroid management alone. Additionally, whether pacemaker insertion alters the clinical outcomes needs further exploration.

Attenuating susceptibility to ascites in cold-stressed broiler chickens fed canola meal-based diets by supplementing arginine or guanidinoacetic acid, either alone or in combination with phenylalanine

OBJECTIVE

The purpose of this study was to determine the effects of dietary supplementation of arginine (ARG) or guanidinoacetic acid (GAA), with or without phenylalanine (PHE), on the ascites susceptibility in the cold-stressed broilers fed canola meal (CM)-based diet.

METHOD

A total of 450 one-day-old male broiler chicks were randomly allocated to 30 floor pens with 6 replications for each of the 5 treatments. The dietary treatments were as follows: CM-based diet (control), CM-based diet + 2.57 g/kg ARG, CM-based diet + 1.8 g/kg GAA, CM-based diet + 2.57 g/kg ARG + 1.5 g/kg PHE and CM-based diet + 1.8 g/kg GAA + 1.5 g/kg PHE. The groups experienced cold stress induction starting at 32°C on day one, with gradual reductions to 15°C on days 21. The temperature was then held at 15°C for the remainder of the experiment.

RESULTS

The supplements ARG + PHE and GAA + PHE resulted in improved feed conversion ratios (FCR) when compared to the control group. In comparison with the control group, supplementation of ARG and ARG + PHE decreased the ascites mortality by increasing the plasma nitric oxide level (NO), blood O2 partial pressure, blood O2 saturation (SO2), and decreasing the blood CO2 partial pressure (PCO2) and right ventricle to total ventricle (RV:TV) ratio. Supplementation of GAA and GAA + PHE also declined ascites mortality by reducing blood PCO2 while increasing blood SO2 and plasma NO levels. Although plasma corticosterone level and RV:TV ratio were similar between the GAA and control groups, adding GAA + PHE significantly reduced both compared to the control group.

CONCLUSION

In summary, supplementing cold-stressed broiler chicken diets with 2.57 g/kg ARG may alleviate hypertension. Additionally, 1.8 g/kg GAA proves to be an effective substitute for dietary ARG in low-ARG diets, alleviating adverse effects from cold stress. Proper PHE formulation, at 1.5 g/kg in this study, is crucial when using ARG and GAA supplements.

Triglyceride Glucose Index: A Potential Indicator in the Evaluation of Graves Ophthalmopathy

PURPOSE

To determine the relationship between Graves ophthalmopathy (GO) and triglyceride glucose index (TGI) and to evaluate the predictive importance of this index in terms of GO activity.

METHODS

This retrospective study included 20 inactive GO patients, 20 active GO patients, and 20 healthy controls. TGI was calculated using fasting plasma triglyceride and fasting plasma glucose levels and values were compared between the groups. The receiver operating characteristics curve was used to calculate the optimal TGI cutoff value and the sensitivity and specificity of this value between active and inactive GO groups.

RESULTS

No significant difference was detected between the groups in terms of age and gender ( p = 0.561 and p = 0.762, respectively). TGI value was 8.49 (8.41, 8.67) in the control group, 8.76 (8.74, 8.87) in the inactive GO group, and 9.06 (8.87, 9.08) in the active GO group ( p < 0.001 for control group vs. inactive GO group; p < 0.001 for control group vs. active GO group; p = 0.001 for inactive GO group vs. active GO group). The optimal receiver operating characteristics cutoff value of TGI between active and inactive GO groups was 8.86 with 85% sensitivity and 75% specificity (area under curve: 0.837, p < 0.001, 95% confidence interval: 0.711-0.964).

CONCLUSION

TGI was higher in both inactive and active GO patients compared with controls. It also appears that TGI may be used as a predictive marker indicating GO activity. This cheap and easily accessible parameter may be beneficial in detecting the disease and monitoring its activity in clinical practice.

Subclinical Hyperthyroidism and Cardiovascular Disease

Background: In this narrative review, we assess published data on subclinical hyperthyroidism (SCHyper) and its association with cardiovascular disease (CVD) in the general population. Summary: We present data on the risk of SCHyper in relation to CVD outcomes, including atrial fibrillation (AF), heart failure, stroke, coronary heart disease (CHD), major adverse cardiac events (MACE), CVD mortality, and all-cause mortality. Evidence indicates that SCHyper is associated with an elevated risk of AF, heart failure, MACE, CVD mortality, and all-cause mortality. SCHyper appears to have little association with stroke risk and has shown conflicting results regarding CHD risk. Regarding the degree of serum TSH suppression, evidence shows a higher risk of CVD in SCHyper individuals with suppressed TSH (<0.1 mIU/L) compared with those with low TSH (0.1-0.4 mIU/L). Despite evidence that older individuals are inherently at a higher risk for CVD, no studies have yet demonstrated an age-related increase in the relative risk of CVD in SCHyper. Conclusion: The studies indicate that SCHyper is associated with an increased risk of AF, heart failure, MACE, CVD mortality, and all-cause mortality. Considering the importance of the degree of serum TSH suppression and age as risk factors for CVD, treatment decisions should be individualized based on their specific risk factors.

Green Tea Intake: A Protective Factor Against Postsurgical Hypothyroidism and Hypoparathyroidism

PURPOSE

Tea and coffee are the most commonly consumed types of drinks, identified with multiple health benefits. However, the association between tea and coffee intake and postsurgical hypothyroidism and hypoparathyroidism (PHypoTP) is still unclear. Therefore, the objective of this study is to explore the effect of tea and coffee intake on the risk of PHypoTP.

DESIGN

Two-sample Mendelian randomization (MR).

METHODS

The primary approach for MR estimates was the inverse-variance-weighted method. MR-Egger, MR Pleiotropy RESidual Sum and Outlier (PRESSO), weighted median, simple mode, and weighted mode were used to detect pleiotropy and heterogeneity.

FINDINGS

We found that green tea intake was causally associated with the decreased risk of PHypoTP (β = -0.019; 95% confidence interval: -0.038 to -0.001; P = .029). However, there was no significant association between coffee intake and the risk of PHypoTP. No heterogeneity or pleiotropy in these results was detected.

CONCLUSIONS

Our findings provide the genetic evidence supporting that green tea intake was a protective factor against PHypoTP. Accordingly, we may suggest that patients after thyroidectomy to add green tea into their habitual diet during nursing education.

Myxedema ascites? A rare presentation of ascites in severe hypothyroidism: A case report and review

Ascites represents an infrequent sequela of hypothyroidism, manifesting in fewer than 4% of affected individuals. Herein, we delineate a case characterized by profound hypothyroidism accompanied by substantial ascites, further complicated by cardiac insufficiency. A 29-year-old female, previously diagnosed with postradiation hypothyroidism subsequent to a diagnosis of Grave's disease 11 years prior, presented with exacerbating dyspnoea, abdominal distension, and orthopnea. In January 2024, she was admitted with massive ascites, exhibiting clinical manifestations of both hypothyroidism and cardiac failure. Thyroid function tests were markedly abnormal, with a thyroid-stimulating hormone level of 77.65 mIU/L, triiodothyronine at 2.2 nmol/L, and thyroxine levels below 3.2 pmol/L. Echocardiographic evaluation revealed dilated cardiomyopathy with a significantly reduced systolic (ejection fraction of 25.9%) and diastolic function (E/A ratio of 0.87). Analysis of the ascitic fluid demonstrated a serum-ascites albumin gradient exceeding 1.1 g/L (3 g/L). Ultrasonography of the abdomen ruled out portal hypertension, while computed tomography of the abdomen confirmed extensive ascites without evidence of malignancy. Under the supervision of a specialist, the patient was administered a high dosage of levothyroxine (300 mcg), leading to a significant amelioration in both thyroid function parameters and her ascites. Subsequent thyroid function tests demonstrated a decrease in thyroid-stimulating hormone levels to 11.7 mIU/L and an increase in thyroxine levels to 15.6 pmol/L, indicating a positive response to the thyroid hormone replacement therapy. Subsequent echocardiographic assessment showed improvement in the ejection fraction to 26.9% and diastolic function (E/A ratio of 1.27). Myxedema ascites, though infrequent, is readily amenable to treatment. The serum-ascites albumin gradient exceeding 1.1 g/L may be indicative of hypothyroidism-associated ascites, although the paucity of studies renders it uncertain whether this is a characteristic feature. Further investigation into the etiology, diagnostic criteria, and management strategies for ascites in the context of hypothyroidism is warranted.

Investigating secondary hypertension in cerebrovascular disease

Hypertension is the leading cause of stroke in the UK and worldwide. In recent years, stroke incidence has increased by 30%-41.5% in people aged under 64 years, with the prevalence of hypertension increasing by 4%-11%. Given that 5%-10% of people with hypertension in the general population have an underlying cause for their elevated blood pressure, it is important that all clinicians should maintain a high clinical suspicion for secondary hypertension. This review provides a clinical perspective of when to consider the underlying causes of secondary hypertension, with investigation algorithms for patients presenting with stroke and hypertension. Early involvement of hypertension specialist services is important to identify secondary causes of hypertension, as its effective control reduces cardiovascular-associated morbidity.

Triiodo-L-thyronine (T3) downregulates Npr1 gene (coding for natriuretic peptide receptor-A) transcription in H9c2 cells: involvement of β-AR-ROS signaling

INTRODUCTION

Natriuretic peptide receptor-A (NPR-A) signaling system is considered as an intrinsic productive mechanism of the heart that opposes abnormal cardiac remodeling and hypertrophic growth. NPR-A is coded by Npr1 gene, and its expression is downregulated in the hypertrophied heart.

AIM

We sought to examine the levels of Npr1 gene transcription in triiodo-L-thyronine (T3) treated hypertrophied cardiomyocyte (H9c2) cells, in vitro, and also the involvement of β-adrenergic receptor (β-AR) - Reactive oxygen species (ROS) signaling system in the down-regulation of Npr1 transcription also studied.

MAIN METHODS

Anti-hypertrophic Npr1 gene transcription was monitored in control and T3-treated (dose and time dependent) H9c2 cells, using a real time PCR method. Further, cell size, intracellular cGMP, ROS, hypertrophy markers (ANP, BNP, α-sk, α-MHC and β-MHC), β-AR, and protein kinase cGMP-dependent 1 (PKG-I) genes expression were also determined. The intracellular cGMP and ROS levels were determined by ELISA and DCF dye method, respectively. In addition, to neutralize T3 mediated ROS generation, H9c2 cells were treated with T3 in the presence and absence of antioxidants [curcumin (CU) or N-acetyl-L-cysteine (NAC)].

RESULTS

A dose dependent (10 pM, 100 pM, 1 nM and 10 nM) and time dependent (12 h, 24 h and 48 h) down-regulation of Npr1 gene transcription (20, 39, 60, and 74% respectively; 18, 55, and 85%, respectively) were observed in T3-treated H9c2 cells as compared with control cells. Immunofluorescence analysis also revealed that a marked down regulation of NPR- A protein in T3-treated cells as compared with control cells. Further, a parallel downregulation of cGMP and PKG-I (2.4 fold) were noticed in the T3-treated cells. In contrast, a time dependent increased expression of β-AR (60, 72, and 80% respectively) and ROS (26, 48, and 74%, respectively) levels were noticed in T3-treated H9c2 cells as compared with control cells. Interestingly, antioxidants, CU or NAC co-treated T3 cells displayed a significant reduction in ROS (69 and 81%, respectively) generation and to increased Npr1 gene transcription (81 and 88%, respectively) as compared with T3 alone treated cells.

CONCLUSION

Our result suggest that down regulation of Npr1 gene transcription is critically involved in T3- induced hypertrophic growth in H9c2 cells, and identifies the cross-talk between T3-β-AR-ROS and NPR-A signaling.

Long-term prognostic value of thyroid hormones in left ventricular noncompaction

PURPOSE

Thyroid function is closely related to the prognosis of cardiovascular diseases. This study aimed to explore the predictive value of thyroid hormones for adverse cardiovascular outcomes in left ventricular noncompaction (LVNC).

METHODS

This longitudinal cohort study enrolled 388 consecutive LVNC patients with complete thyroid function profiles and comprehensive cardiovascular assessment. Potential predictors for adverse outcomes were thoroughly evaluated.

RESULTS

Over a median follow-up of 5.22 years, primary outcome (the combination of cardiovascular mortality and heart transplantation) occurred in 98 (25.3%) patients. For secondary outcomes, 75 (19.3%) patients died and 130 (33.5%) patients experienced major adverse cardiovascular events (MACE). Multivariable Cox analysis identified that free triiodothyronine (FT3) was independently associated with both primary (HR 0.455, 95%CI 0.313-0.664) and secondary (HR 0.547, 95%CI 0.349-0.858; HR 0.663, 95%CI 0.475-0.925) outcomes. Restricted cubic spline analysis illustrated that the risk for adverse outcomes increased significantly with the decline of serum FT3. The LVNC cohort was further stratified according to tertiles of FT3 levels. Individuals with lower FT3 levels in the tertile 1 group suffered from severe cardiac dysfunction and remodeling, resulting in higher incidence of mortality and MACE (Log-rank P < 0.001). Subgroup analysis revealed that lower concentration of FT3 was linked to worse prognosis, particularly for patients with left atrial diameter ≥ 40 mm or left ventricular ejection fraction ≤ 35%. Adding FT3 to the pre-existing risk score for MACE in LVNC improved its predictive performance.

CONCLUSION

Through the long-term investigation on a large LVNC cohort, we demonstrated that low FT3 level was an independent predictor for adverse cardiovascular outcomes.

Unusual Presentations of Thyrotoxic Tricuspid and Mitral Regurgitations in 62 Adults: A Systematic Review of Case Reports with In-depth Pathophysiological Review

Background

Thyrotoxicosis is related to cardiovascular mortality. This can be caused by several clinical manifestations involving the rare provocation of tricuspid regurgitation (TR) and mitral regurgitation (MR). However, there are still no clear data on thyrotoxic TR and/or MR. This study examines the progression of TR, MR, heart failure (HF) and pulmonary hypertension (PH) in response to the thyrotoxic heart manifestations, clinical characteristics and treatment approaches.

Methods

A PRISMA-based systematic search was conducted using PubMed and other databases up to 17 June 2023. The outcomes of this study were TR, MR, HF and PH with their progression on follow-up, clinical characteristics and treatment approaches.

Results

A total of 57 case reports involving 62 patients (45.77 ± 13.41 years) were included in this study. They were predominantly women (n=50; 80.65%) and diagnosed with Graves' disease (n=41; 75.81%). All patients were diagnosed with thyrotoxicosis, and this included 23 (37.10%) cases of thyroid storm. From echocardiographic studies, several patients improved clinically within the first 6 months of follow-up, including 20 TR patients (83.33%) in 6 months, nine MR patients (69.23%) in 3 months, eight HF patients (66.67%) in 2 months and 16 PH patients (76.19%) in 6 months.

Conclusion

Several mechanisms are involved in thyrotoxic TR and/or MR, including the direct thyroid hormone effect and the indirect effect of other hyperthyroidism-associated factors. Patients with thyrotoxic TR and/or MR, including those with HF and PH, can experience clinical and structural improvements following hyperthyroidism treatment in the first 6 months.

Thyroid Hormone Receptors in Control of Heart Rate

Thyroid hormone has profound effects on cardiovascular functions, including heart rate. These effects can be mediated directly, for example, by changing the expression of target genes in the heart through nuclear thyroid hormone receptors, or indirectly by altering the autonomic nervous systems output of the brain. The underlying molecular mechanisms as well as the cellular substrates, however, are far from being understood. In this review, we summarize the recent key findings on the individual contributions of the two thyroid hormone receptor isoforms on the regulation of heart rate, challenging the role of the pacemaker channel genes Hcn2 and Hcn4 as sole mediators of the hormone's effect. Furthermore, we discuss the possible actions of thyroid hormone on the autonomic nervous system affecting heart rate distribution, and highlight the possibility of permanent alterations in heart and brain by impaired thyroid hormone action during development as important factors to consider when analyzing or designing experiments.

Organ injury and its management in heart failure: Liver, kidney, and thyroid gland dysfunction

Heart failure is hemodynamically characterized as congestion and/or end-organ hypoperfusion, and is associated with increased morbidity and mortality. Underlying pathophysiology, such as neuro-hormonal activation, exacerbates heart failure and leads to functional deterioration of other organs. We have been conducting clinical research to study the pathophysiology of heart failure and discover prognostic factors. In this review article, we report the results and implications of our clinical research on heart failure.

Association between FT3 Levels and Exercise-Induced Cardiac Remodeling in Elite Athletes

BACKGROUND

Previous studies demonstrated that variations of fT3, even within the euthyroid range, can influence cardiac function. Our aim was to investigate whether thyroid hormones, even within the euthyroid range, are associated with the magnitude of exercise-induced cardiac remodeling in Olympic athletes.

METHODS

We evaluated 1342 Olympic athletes (mean age 25.6 ± 5.1) practicing different sporting disciplines (power, skills, endurance, and mixed). Athletes underwent blood testing (thyroid stimulating hormone, fT3, and fT4), echocardiography, and exercise-stress testing. Athletes taking thyroid hormones, affected by thyroiditis, or presenting TSH out of ranges were excluded.

RESULTS

The level of thyroid hormones varied according to the type of sporting discipline practiced: endurance athletes presented the lowest TSH (p < 0.0001), fT3 (p = 0.007), and fT4 (p < 0.0001) in comparison to the remaining ones. Resting heart rate (HR) was positively correlated to fT3 in athletes of different disciplines (power: p = 0.0002, R2 = 0.04; skill: p = 0.0009, R2 = 0.05; endurance: p = 0.007, R2 = 0.03; and mixed: p = 0.04, R2 = 0.01). The same results were seen for peak HR in the exercise-stress test in athletes engaged in power, skill, and endurance (respectively, p < 0.0001, R2 = 0.04; p = 0.01, R2 = 0.04; and p = 0.005, R2 = 0.02). Moreover, a positive correlation was observed with cardiac dimensions, i.e., interventricular septum (power: p < 0.0001, R2 = 0.11; skill: p = 0.02, R2 = 0.03; endurance: p = 0.002, R2 = 0.03; mixed: p < 0.0001, R2 = 0.04). Furthermore, fT3 was directly correlated with the left ventricle (LV) end-diastolic volume in skills (p = 0.04, R2 = 0.03), endurance (p = 0.04, R2 = 0.01), and mixed (p = 0.04, R2 = 0.01).

CONCLUSIONS

Thyroid hormones, even within the euthyroid range, are associated with cardiac adaptive response to exercise and may contribute to exercise-induced cardiac remodeling.

Changes of cardiac function: cardiac adaptation in patients with hypothyroidism assessed by cardiac magnetic resonance-a meta-analysis

Objective

The meta-analysis aimed to explore the cardiac adaptation in hypothyroidism patients by cardiac magnetic resonance.

Research methods and procedures

Databases including PubMed, Cochrane Library, Embase, CNKI, and Sinomed for clinical studies of hypothyroidism on cardiac function changes. Databases were searched from the earliest data to 15 June 2023. Two authors retrieved studies and evaluated their quality. Review Manager 5.4.1 and Stata18 were used to analyze the data. This study is registered with the International Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY), 202440114.

Results

Six studies were selected for further analysis. Five of them reported differences in cardiac function measures between patients with hypothyroidism and healthy controls, and three studies reported cardiac function parameters after treatment in patients with hypothyroidism. The fixed-effect model combined WMD values for left ventricular ejection fraction (LVEF) had a pooled effect size of -1.98 (95% CI -3.50 to -0.44], P=0.01), implying that LVEF was lower in patients with hypothyroidism than in healthy people. Analysis of heterogeneity found moderate heterogeneity (P = 0.08, I² = 50%). WMD values for stroke volume (SV), cardiac index (CI), left ventricular end-diastolic volume index(LVEDVI), left ventricular end-systolic volume (LESVI), and left ventricular mass index(LVMI) were also analyzed, and pooled effect sizes showed the CI and LVEDVI of patients with hypothyroidism ware significantly decrease (WMD=-0.47, 95% CI [-0.93 to -0.00], P=0.05, WMD=-7.99, 95%CI [-14.01 to -1.96], P=0.009, respectively). Patients with hypothyroidism tended to recover cardiac function after treatment [LVEF (WMD = 6.37, 95%CI [2.05, 10.69], P=0.004), SV (WMD = 7.67, 95%CI [1.61, 13.74], P=0.01), CI (WMD = 0.40, 95%CI [0.01, 0.79], P=0.05)], and there was no difference from the healthy controls.

Conclusion

Hypothyroidism could affect cardiac function, although this does not cause significant heart failure. It may be an adaptation of the heart to the hypothyroid state. There was a risk that this adaptation may turn into myocardial damage. Cardiac function could be restored after treatment in patients with hypothyroidism. Aggressive levothyroxine replacement therapy should be used to reverse cardiac function.

Systematic review registration

https://inplasy.com, identifier (INPLASY202440114).

Control rate of hyperthyroidism and its associated factors after prolonged use of anti-thyroid drugs in a hospital setting, Northwest Ethiopia

Hyperthyroidism is increased synthesis and secretion of thyroid hormones by the thyroid gland resulting in thyrotoxicosis. The modality of therapy for hyperthyroidism includes anti-thyroid drugs, radioiodine and surgery. Anti-thyroid drugs are the only available therapy for hyperthyroid patients in developing world as radioiodine is inaccessible and surgical set up does not exist as required. The aim of this study was to determine the magnitude and predictors of uncontrolled hyperthyroidism among hyperthyroid patients after prolonged anti-thyroid drug use. An institutional-based cross sectional study was conducted at the University of Gondar hospital, Northwest Ethiopia, between April 1, 2022 and October 31, 2022. A consecutive sampling method was used to recruit 317 study subjects. Data were collected through a pre-designed questionnaire. Patients were interviewed to obtain socio-demographic data and relevant medical information. Laboratory analyses were done based on the follow up protocol. Data were entered into EPI Info version 4.6.0.0 (EPI Info, Atlanta) and analyzed in STATA version 14 (Stata Corp LP, Texas, USA). Binary logistic regression model was used to identify variables associated with uncontrolled hyperthyroidism among hyperthyroid patients. P value < .05 was used to declare significant association. A total of 317 patients with hyperthyroidism were included in the study. The median age of the study subjects was 45 years (IQR 36-55 years). Most (95%) of the study participants were females. Toxic multi-nodular goiter was the most common cause of hyperthyroidism (92%), followed by toxic adenoma (5%) and Graves' disease (2%). On multivariate binary logistic regression, large goiter size (AOR: 3.163, 95% CI [1.333-7.506]), severe disease (AOR: 2.275, 95% CI [1.060-4.880]), infrequent iodinated salt intake (AOR: 3.668, 95% CI [1.245-10.802]), and poor adherence to anti-thyroid drug (AOR:15.724, 95% CI [5.542-44.610]) were statistically significant with uncontrolled hyperthyroidism at 12 months of anti-thyroid drug intake. A quarter of patients with hyperthyroidism didn't achieve euthyroid state after 12 months of anti-thyroid drug use. The identified predictors for non-euthyroid state were large goiter size, severe disease, infrequent iodinated salt intake, and poor adherence to anti-thyroid drug.

Long-term Effect of Thyrotropin-binding Inhibitor Immunoglobulin on Atrial Fibrillation in Euthyroid Patients

OBJECTIVE

Individuals with hyperthyroidism are at an increased risk of atrial fibrillation (AF), but the association between autoantibodies and AF or cardiovascular mortality in individuals who have returned to normal thyroid function remains unclear.

METHODS

The study utilized electronic medical records from National Taiwan University Hospital between 2000 and 2022. Each hyperthyroidism patient had at least 1 thyrotropin-binding inhibiting immunoglobulin (TBII) measurement. The relationship between TBII levels and the risk of AF and cardiovascular mortality was assessed using multivariable Cox regression models and Kaplan-Meier survival analysis.

RESULTS

Among the 14 618 enrolled patients over a 20-year timeframe, 173 individuals developed AF, while 46 experienced cardiovascular mortality. TBII values exceeding 35% were significantly associated with an elevated risk of AF for both the first TBII (hazard ratio {HR} 1.48 [1.05-2.08], P = .027) and mean TBII (HR 1.91 [1.37-2.65], P < .001). Furthermore, after free T4 levels had normalized, a borderline association between first TBII and AF (HR 1.59 [0.99-2.56], P = .056) was observed, while higher mean TBII increased AF (HR 1.78 [1.11-2.85], P = .017). Higher first and mean TBII burden continued to significantly impact the incidence of cardiovascular mortality (HR 6.73 [1.42-31.82], P = .016; 7.87 [1.66-37.20], P = .009). Kaplan-Meier analysis demonstrated that elevated TBII levels increased the risk of AF and cardiac mortality (log-rank P = .035 and .027, respectively).

CONCLUSION

In euthyroid individuals following antithyroid treatment, elevated circulating TBII levels and burden are associated with an elevated risk of long-term incident AF and cardiovascular mortality. Further reduction of TBII level below 35% will benefit to clinical outcomes.

Cardiovascular mechanisms of thyroid hormones and heart failure: Current knowledge and perspectives

A multiple hormonal imbalance that accompanies heart failure (HF) may have a significant impact on the clinical course in such patients. The non-thyroidal illness syndrome (NTIS), also referred to as euthyroid sick syndrome or low triiodothyronine syndrome, can be found in about 30% of patients with HF. NTIS represents a systemic adaptation to chronic illness that is associated with increased cardiac and overall mortality in patients with HF. While conclusions on thyroid-stimulating hormone, free triiodothyronine, total and free thyroxine are currently unresolved, serum total triiodothyronine levels and the ratio of free triiodothyronine to free thyroxine seem to provide the best correlates to the echocardiographic, laboratory and clinical parameters of disease severity. HF patients with either hyper- or hypothyroidism should be treated according to the appropriate guidelines, but the therapeutic approach to NTIS, with or without HF, is still a matter of debate. Possible treatment options include better individual titration of levothyroxine therapy, combined triiodothyronine plus thyroxine therapy and natural measures to increase triiodothyronine. Future research should further examine the cellular and tissue mechanisms of NTIS as well as new therapeutic avenues in patients with HF.

Thyrotoxic Cardiomyopathy: A Rare Case of Thyroid Storm Presenting as De Novo Heart Failure

Thyroid storm and heart failure represent formidable challenges in clinical practice. Their coexistence, however, poses an even greater threat to the patient's well-being. To facilitate early recognition and appropriate management, an understanding of the complex interplay between these two conditions is crucial. Through comprehensive assessment, vigilant monitoring, and prompt intervention, outcomes can be improved and the morbidity and mortality mitigated. We present a rare case of a 40-year-old male who presented with severe de novo heart failure and a concurrent thyroid storm. Despite an initial left ventricular systolic ejection fraction of 20% and evidence of global dilatation and hypokinesis on echocardiography, appropriate management resulted in improved clinical status and ultimately recovery of cardiac function.

Subclinical hypothyroidism and clinical outcomes after cardiac surgery: A systematic review and meta-analysis

Background

Subclinical hypothyroidism (SCH) is associated with major adverse cardiovascular events. Despite the recognized negative impact of SCH on cardiovascular health, research on cardiac postoperative outcomes with SCH has yielded conflicting results, and patients are not currently treated for SCH before cardiac surgery procedures.

Methods

We performed a study-level meta-analysis on the impact of SCH on patients undergoing nonurgent cardiac surgery, including coronary artery bypass grafting and valve and aortic surgery. The primary outcome was operative mortality. Secondary outcomes were hospital length of stay (LOS), intensive care unit (ICU) stay, postoperative atrial fibrillation (POAF), intra-aortic balloon pump (IABP) use, renal complications, and long-term all-cause mortality.

Results

Seven observational studies, with a total of 3445 patients, including 851 [24.7%] diagnosed with SCH and 2594 [75.3%] euthyroid patients) were identified. Compared to euthyroid patients, the patients with SCH had higher rates of operative mortality (odds ratio [OR], 2.57; 95% confidence interval [CI], 1.09-6.04; P = .03), prolonged hospital LOS (standardized mean difference, 0.32; 95% CI, 0.02-0.62; P = .04), a higher rate of renal complications (OR, 2.53; 95% CI, 1.74-3.69; P < .0001), but no significant differences in ICU stay, POAF, or IABP use. At mean follow-up of 49.3 months, the presence of SCH was associated with a higher rate of all-cause mortality (incidence rate ratio, 1.82; 95% CI, 1.18-2.83; P = .02).

Conclusions

Patients with SCH have higher operative mortality, prolonged hospital LOS, and increased renal complications after cardiac surgery. Achieving and maintaining a euthyroid state prior to and after cardiac surgery procedures might improve outcomes in these patients.

Atypical Clinical Courses of Graves' Disease Confound Differential Diagnosis of Hyperthyroidism

BACKGROUND

This study examined the appropriateness of the current paradigm for differential diagnosis of painless thyroiditis and Graves' disease (GD) in patients with thyrotoxicosis.

METHODS

We retrospectively evaluated the clinical course of 343 consecutive patients with hyperthyroidism diagnosed by Tc-99m pertechnetate thyroid uptake (TcTU) testing at our hospital from January 2011 to December 2017.

RESULTS

Of the 263 patients with normal or high TcTU levels (≥1.0%), 255 (97%) had unequivocal GD and 5 had spontaneous remission GD or atypical GD. Of the 10 patients with low TcTU levels (<1.0% and ≥0.5%), 7 had GD, while others had subclinical GD, spontaneous remission GD with later relapse, and painless thyroiditis. Of those with very low TcTU levels (<0.5%), most had thyroiditis (painless thyroiditis, 33/67 [49%]; subacute thyroiditis, 29/67 [43%]), and some were positive for anti-TSH receptor antibodies.

CONCLUSION

Given that atypical GD may confound the diagnosis of thyrotoxicosis, it is essential to follow the patient as a tentative diagnosis, whatever the diagnosis. This is the first report clearly demonstrating that so far there is no gold standard for the diagnosis of GD. It is therefore urgent to establish a consensus on the definition of GD so that the specificity and sensitivity of future diagnostic tests can be determined.

A high level of thyroid-stimulating hormone is a risk factor for the development of chronic kidney disease in men: a 10-year cohort study

Hypothyroidism has been reported to be associated with chronic kidney disease (CKD). However, the impact of thyroid-stimulating hormone (TSH) on new onset of CKD and its gender dependence remain undetermined. We investigated the association of serum TSH level and the development of CKD defined by estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 or positive for urine protein in 28,990 Japanese subjects who received annual health examinations. After excluding subjects with no data for serum TSH, urinalysis and eGFR and those with CKD at baseline, a total of 10,392 subjects (men/women: 6802/3590, mean age: 48 years) were recruited. During a 10-year follow-up, 1185 men (6.7%) and 578 women (2.9%) newly developed CKD. Multivariable Cox proportional hazard models after adjustment of age, body mass index, smoking habit, hypertension, diabetes mellitus, dyslipidemia, ischemic heart disease and eGFR (≥ 90 mL/min/1.73 m2) showed that the hazard ratio (HR) for the development of CKD in the high TSH (> 4.2 mU/L) group was significantly higher than that in the low TSH (≤ 4.2 mU/L) group in men (HR [95% confidence interval]: 1.41 [1.09-1.83]) but not in women (1.08 [0.77-1.51]). There was a significant interaction between sex and the category of TSH level for the development of CKD (p = 0.02). The adjusted HR with a restricted cubic spline increased with a higher level of TSH in men but not in women. In conclusion, a high level of TSH is associated with an increased risk for the development of CKD in men but not in women.

Thyroid dysfunction and mortality in cardiovascular hospitalized patients

Background

Thyroid dysfunction (TD) is associated with increased cardiovascular morbidity and mortality. Early detection may influence the clinical management.

Objective

To determine the prevalence, predictors, and prognostic value of TD among hospitalized cardiac patients.

Methods

A retrospective analysis of a 12-year database consisting of nonselectively adult patients admitted to a Cardiology Department and who were all screened for serum thyroid-stimulation-hormone (TSH) levels . Statistical analysis of demographic and clinical characteristics, mortality and length of hospital stay (LOS) was performed.

Results

A total of 14369 patients were included in the study; mean age was 67 years, 38.3% females. 1465 patients (10.2%) had TD. The most frequent type of TD was mildly elevated TSH (5.4%) followed by mildly reduced TSH (2.1%), markedly elevated TSH (1.5%), and markedly reduced TSH (1.2%). Female gender, history of hypothyroidism, heart failure, atrial fibrillation, renal failure and amiodarone use were significantly associated with TD. During follow-up 2975 (20.7%) patients died. There was increased mortality in the mildly reduced TSH subgroup (hazard ratio [HR] =1.44), markedly elevated TSH subgroup (HR=1.40) and mildly elevated TSH subgroup (HR=1.27). LOS was longer for patients with TD; the longest stay was observed in the markedly elevated TSH subgroup (odds ratio=1.69).

Conclusion

The prevalence of TD in hospitalized cardiac patients is 10.2%. TD is associated with an increased mortality rate and LOS. Consequently, routine screening for thyroid function in this population is advisable, particularly for selected high-risk subgroups. Future studies are needed to determine whether optimizing thyroid function can improve survival in these patients.

Cardiac recovery from pressure overload is not altered by thyroid hormone status in old mice

Introduction

Thyroid hormones (THs) are known to have various effects on the cardiovascular system. However, the impact of TH levels on preexisting cardiac diseases is still unclear. Pressure overload due to arterial hypertension or aortic stenosis and aging are major risk factors for the development of structural and functional abnormalities and subsequent heart failure. Here, we assessed the sensitivity to altered TH levels in aged mice with maladaptive cardiac hypertrophy and cardiac dysfunction induced by transverse aortic constriction (TAC).

Methods

Mice at the age of 12 months underwent TAC and received T4 or anti-thyroid medication in drinking water over the course of 4 weeks after induction of left ventricular pressure overload.

Results

T4 excess or deprivation in older mice had no or only very little impact on cardiac function (fractional shortening), cardiac remodeling (cardiac wall thickness, heart weight, cardiomyocyte size, apoptosis, and interstitial fibrosis), and mortality. This is surprising because T4 excess or deprivation had significantly changed the outcome after TAC in young 8-week-old mice. Comparing the gene expression of deiodinases (Dio) 2 and 3 and TH receptor alpha (TRα) 1 and the dominant-negative acting isoform TRα2 between young and aged mice revealed that aged mice exhibited a higher expression of TRα2 and Dio3, while expression of Dio2 was reduced compared with young mice. These changes in Dio2 and 3 expressions might lead to reduced TH availability in the hearts of 12-month-old mice accompanied by reduced TRα action due to higher TRα2.

Discussion

In summary, our study shows that low and high TH availability have little impact on cardiac function and remodeling in older mice with preexisting pressure-induced cardiac damage. This observation seems to be the result of an altered expression of deiodinases and TRα isoforms, thus suggesting that even though cardiovascular risk is increasing with age, the response to TH stress may be dampened in certain conditions.

Co-Morbid Hypothyroidism and Liver Dysfunction: A Review

The liver and thyroid hormones interact at multiple levels to maintain homoeostasis. The liver requires large adequate amounts of thyroid hormones to execute its metabolic functions optimally, and deficiency of thyroid hormones may lead to liver dysfunction. Hypothyroidism has been associated with abnormal lipid metabolism, non-alcoholic fatty liver disease (NAFLD), hypothyroidism-induced myopathy, hypothyroidism-associated gallstones and occasionally, interferon-induced thyroid dysfunction. NAFLD remain an important association with hypothyroidism and further studies are needed that specifically compare the natural course of NAFLD secondary to hypothyroidism and primary NAFLD. Hepatic dysfunction associated with hypothyroidism is usually reverted by normalizing thyroid status. Large scale studies geared towards finding new and effective therapies, especially for NAFLD are needed. The clinician must be aware that there exists overlapping symptomatology between liver dysfunction and severe hypothyroidism which may make delay the diagnosis and treatment of hypothyroidism; this requires a high index of suspicion.

Drug-induced atrial fibrillation. A narrative review of a forgotten adverse effect

Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with an increased morbidity and mortality. There is clinical evidence that an increasing number of cardiovascular and non-cardiovascular drugs, mainly anticancer drugs, can induce AF either in patients with or without pre-existing cardiac disorders, but drug-induced AF (DIAF) has not received the attention that it might deserve. In many cases DIAF is asymptomatic and paroxysmal and patients recover sinus rhythm spontaneously, but sometimes, DIAF persists, and it is necessary to perform a cardioversion. Furthermore, DIAF is not mentioned in clinical guidelines on the treatment of AF. The risk of DIAF increases in elderly and in patients treated with polypharmacy and with risk factors and comorbidities that commonly coexist with AF. This is the case of cancer patients. Under these circumstances ascribing causality of DIAF to a given drug often represents a clinical challenge. We review the incidence, the pathophysiological mechanisms, risk factors, clinical relevance, and treatment of DIAF. Because of the limited information presently available, further research is needed to obtain a deeper insight into DIAF. Meanwhile, it is important that clinicians are aware of the problem that DIAF represents, recognize which drugs may cause DIAF, and consider the possibility that a drug may be responsible for a new-onset AF episode.

The hysteresis damage of cold exposure on tissue and transcript levels in mice

OBJECTIVES

Although cold stress-induced damage to the heart and thyroid has been reported, specific organ associations between the heart and thyroid with delayed injury mechanisms have not been investigated. In this study, we determined the damage time and transcript levels of a large number of genes in the heart and thyroid after cold exposure. Meanwhile, we analysed the relationship between heart and thyroid injury in human medical records to determine the association of delayed injury from cold exposure.

METHODS

Mice were exposed to cold stress and hysteresis injury. Gene changes at the transcriptional level were detected using high throughput sequencing technology. The most variable genes were verified at the protein level using Western Blotting and medical records were collected and analysed.

RESULTS

The damage was the most severe when the animals were allowed to recover to room temperature for 4 h after exposure to cold stress. During this process, STAT1 and ATF3 genes were acutely up-regulated. Analysis of human medical records showed the highest correlation between AST and T4 under cold stress (p = 0.0011).

CONCLUSIONS

Exposure to cold increases blood level of free thyroid hormone and biomarkers of myocardial injury, as well as related mRNA levels. These changes were more pronounced after return to room temperature.

Prognostic implications of thyroid disease in patients with atrial fibrillation

Atrial fibrillation (AF) is often accompanied by thyroid disease (THD). This study aimed to explore the relationship between THD and the occurrence of significant clinical outcomes in patients with AF. This post hoc analysis utilized data from the MISOAC-AF trial (NCT02941978), which enrolled hospitalized patients with AF. Patients were categorized based on their THD history into hyperthyroidism, hypothyroidism, or euthyroidism. Cox regression models were employed to calculate unadjusted and adjusted hazard ratios (aHRs). The primary outcomes of interest included all-cause mortality, cardiovascular death, and hospitalizations during the follow-up period. The study included 496 AF patients (mean age 73.09 ± 11.10 years) with available THD data, who were followed-up for a median duration of 31 months. Among them, 16 patients (3.2%) had hyperthyroidism, 141 (28.4%) had hypothyroidism, and 339 (68.4%) had no thyroid disease. Patients with hypothyroidism exhibited higher rates of hospitalization during follow-up (aHR: 1.57, 95% CI 1.12 to 2.20, p = 0.025) compared to the euthyroid group. Elevated levels of thyroid-stimulating hormone (TSH) were correlated with an increased risk of cardiovascular mortality (aHR: 1.03, 95% CI 1.01 to 1.05, p = 0.007) and hospitalizations (aHR: 1.06, 95% CI 1.01 to 1.12, p = 0.03). Conversely, lower levels of triiodothyronine (T3) were associated with higher risks of all-cause mortality (aHR: 0.51, 95% CI 0.31 to 0.82, p = 0.006) and cardiovascular mortality (aHR: 0.42, 95% CI 0.23 to 0.77, p = 0.005). Among patients with AF, hypothyroidism was associated with increased hospitalizations. Furthermore, elevated TSH levels and decreased T3 levels were linked to higher cardiovascular and all-cause mortality risks, respectively.

Association of DIO2 and MCT10 Polymorphisms With Persistent Symptoms in LT4-Treated Patients in the UK Biobank

CONTEXT

Some evidence suggests gene-treatment interactions might cause persistent symptoms in individuals receiving levothyroxine (LT4) treatment.

OBJECTIVE

We investigated, as previously hypothesized, if single-nucleotide variations (SNVs; formerly single-nucleotide polymorphisms) in rs225014 (Thr92Ala), rs225015, or rs12885300 (ORFa-Gly3Asp) in the deiodinase 2 gene (DIO2), or rs17606253 in the monocarboxylate transporter 10 gene (MCT10) were associated with outcomes indicative of local tissue hypothyroidism in LT4-treated patients and controls.

METHODS

We included 18 761 LT4-treated patients and 360 534 controls in a population-based cross-sectional study in the UK Biobank. LT4 treatment was defined as a diagnosis of hypothyroidism and self-reported use of LT4 without use of 3,5,3'-triiodothyronine. Outcomes were psychological well-being, cognitive function, and cardiovascular risk factors. Associations were evaluated by linear, logistic, or ordinal logistic multiple regression. Adjustments included sex, age, sex-age interaction, and genetic principal components 1 to 10.

RESULTS

Compared to controls, LT4 treatment was adversely associated with almost all outcomes, most noteworthy: Increased frequency of tiredness (P < .001), decreased well-being factor score (P < .001), increased reaction-time (P < .001), and increased body mass index (P < .001). Except for a significant association between the minor rs225015 A allele and financial dissatisfaction, there was no association of rs225014, rs225015, rs12885300, or rs17606253 with any outcomes in LT4-treated patients. For all outcomes, carrying the risk allele at these 4 SNVs did not amplify symptoms associated with LT4 treatment compared to controls.

CONCLUSION

rs225014, rs225015, rs12885300, and rs17606253 could not explain changed psychological well-being, cognitive function, or cardiovascular risk factors in LT4-treated patients. Our findings do not support a gene-treatment interaction between these SNVs and LT4 treatment.

Temperature Differences Between Controlled Primary Hypothyroidism and Healthy Patients: An Exploratory Study

Introduction

Hypothyroidism is conventionally treated with replacement therapy through levothyroxine (LT4). Despite the improvement in symptoms, cold intolerance persists in some patients. The present study aims to determine whether there is a difference in temperature perception and skin temperature between patients with primary controlled hypothyroidism (PCH) and a group of healthy controls matched for body mass index and age. Secondarily we aimed to determine difference in quality of life.

Methodology

Skin temperature measurements were performed in both groups, both in the central and peripheral regions of the body. In addition, subjects were asked about their perception of temperature in a temperature-controlled room; anthropometric measurements were taken, their quality of life was assessed using the ThyPRO-39, and a thyroid hormone profile was performed.

Results

Eleven patients in the PCH group and 30 patients in the control group were studied. It was found that the group with PCH presented a significantly lower palmar temperature than the control group [mean (SD) of 32.05 (1.79) vs 33.10 (1.30) oC, P = .046]. A mediation model showed a direct effect. Temperature perception was equal between groups. The median (interquartile range) of ThyPRO was 8 (5.2) points in the control group vs 21.8 (13.5) in the group of controlled hypothyroidism, P < .001.

Discussion

These results suggest that, despite LT4 treatment, patients continue to present abnormalities in thermogenesis-related thermogenesis, and this may be due to a lack of hormonal adaptation to environmental changes and physiological demands, leading to lower body temperatures and increased sensitivity to cold.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Patients With Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

Roles of β-adrenoceptor Subtypes and Therapeutics in Human Cardiovascular Disease: Heart Failure, Tachyarrhythmias and Other Cardiovascular Disorders

β-Adrenoceptors (β-ARs) provide an important therapeutic target for the treatment of cardiovascular disease. Three β-ARs, β1-AR, β2-AR, β3-AR are localized to the human heart. Activation of β1-AR and β2-ARs increases heart rate, force of contraction (inotropy) and consequently cardiac output to meet physiological demand. However, in disease, chronic over-activation of β1-AR is responsible for the progression of disease (e.g. heart failure) mediated by pathological hypertrophy, adverse remodelling and premature cell death. Furthermore, activation of β1-AR is critical in the pathogenesis of cardiac arrhythmias while activation of β2-AR directly influences blood pressure haemostasis. There is an increasing awareness of the contribution of β2-AR in cardiovascular disease, particularly arrhythmia generation. All β-blockers used therapeutically to treat cardiovascular disease block β1-AR with variable blockade of β2-AR depending on relative affinity for β1-AR vs β2-AR. Since the introduction of β-blockers into clinical practice in 1965, β-blockers with different properties have been trialled, used and evaluated, leading to better understanding of their therapeutic effects and tolerability in various cardiovascular conditions. β-Blockers with the property of intrinsic sympathomimetic activity (ISA), i.e. β-blockers that also activate the receptor, were used in the past for post-treatment of myocardial infarction and had limited use in heart failure. The β-blocker carvedilol continues to intrigue due to numerous properties that differentiate it from other β-blockers and is used successfully in the treatment of heart failure. The discovery of β3-AR in human heart created interest in the role of β3-AR in heart failure but has not resulted in therapeutics at this stage.

Impact of Thyroid Status on Incident Kidney Dysfunction and Chronic Kidney Disease Progression in a Nationally Representative Cohort

OBJECTIVE

To examine the relationship between thyroid status and incident kidney dysfunction/chronic kidney disease (CKD) progression.

PATIENTS AND METHODS

We examined incident thyroid status, ascertained by serum thyrotropin (TSH) levels measured from January 1, 2007, through December 31, 2018, among 4,152,830 patients from the Optum Labs Data Warehouse, containing deidentified retrospective administrative claims data from a large national health insurance plan and electronic health record data from a nationwide network of provider groups. Associations of thyroid status, categorized as hypothyroidism, euthyroidism, or hyperthyroidism (TSH levels >5.0, 0.5-5.0, and <0.5 mIU/L, respectively), with the composite end point of incident kidney dysfunction in patients without baseline kidney dysfunction and CKD progression in those with baseline CKD were examined using Cox models.

RESULTS

Patients with hypothyroidism and hyperthyroidism had higher risk of incident kidney dysfunction/CKD progression in expanded case-mix analyses (reference: euthyroidism): adjusted hazard ratios (aHRs) (95% CIs) were 1.37 (1.34 to 1.40) and 1.42 (1.39 to 1.45), respectively. Incrementally higher TSH levels in the upper reference range and TSH ranges for subclinical, mild overt, and overt hypothyroidism (≥3.0-5.0, >5.0-10.0, >10.0-20.0, and >20.0 mIU/L, respectively) were associated with increasingly higher risk of the composite end point (reference: TSH level, 0.5 to <3.0 mIU/L): aHRs (95% CIs) were 1.10 (1.09 to 1.11), 1.37 (1.34 to 1.40), 1.70 (1.59 to 1.83), and 1.70 (1.50 to 1.93), respectively. Incrementally lower TSH levels in the subclinical (<0.5 mIU/L) and overt (<0.1 mIU/L) hyperthyroid ranges were also associated with the composite end point: aHRs (95% CIs) were 1.44 (1.41 to 1.47) and 1.48 (1.39 to 1.59), respectively.

CONCLUSION

In a national cohort, TSH levels in the upper reference range or higher (≥3.0 mIU/L) and below the reference range (<0.5 mIU/L) were associated with incident kidney dysfunction/CKD progression.

Hypothyroidism in acute coronary syndrome - A prospective Indian study

BACKGROUND

Evidence suggests that hypothyroidism may be associated with an increased risk of acute coronary syndrome (ACS). The data regarding the influence of hypothyroidism on cardiovascular disease in the Asian population is conflicting. Therefore, we undertook this study to assess the overall prevalence of hypothyroidism in Acute Coronary Syndrome (ACS) patients and determine if there is a relationship between hypothyroidism, both sub-clinical and overt and other significant risk factors of ACS in an Indian population.

METHODS

We studied 487 hospitalized patients between March 2018 and February 2021 with a diagnosis of ACS to determine the prevalence of hypothyroidism, both clinical and sub-clinical and their relationship with other known coronary risk factors. Thyroid function Tests - free T3, free T4 and TSH were collected from all the patients within 24 h of their admission to the coronary care unit (CCU) of 2 major hospitals in New Delhi and Imphal (Manipur).

RESULTS

Subclinical hypothyroidism was prevalent in 44 (9 %), followed by overt hypothyroidism in 25 (5.2 %). Subclinical hypothyroidism was more common in females, whereas overt hypothyroidism was more common in males. ST Elevation Myocardial Infarction (STEMI) (52 %), followed by Non-ST-Elevation Myocardial Infarction (NSTEMI) (25 %), was the commonest diagnosis at presentation. Patients with overt hypothyroidism showed a higher proportion of increased triglyceride levels. Patients with hypothyroidism had no differences in the prevalence of concomitant diabetes hypertension and other coronary risk factors.

CONCLUSIONS

Patients with ACS without known thyroid disorders should be screened for hypothyroidism since it is found frequently. There might be a case to treat their thyroid dysfunction appropriately.

Higher Risk of Incident Hyperthyroidism in Patients With Atrial Fibrillation

BACKGROUND

Atrial fibrillation (AF) has been linked to increased hyperthyroidism risk, but contributing factors are unclear.

OBJECTIVE

We aimed to investigate whether AF could predict hyperthyroidism and related risk factors.

METHODS

This retrospective cohort study was conducted in a tertiary medical institution and included patients aged 18 years or older with AF but without hyperthyroidism at diagnosis. The endpoint was defined as newly diagnosed hyperthyroidism during the follow-up period.

RESULTS

The study cohort included 8552 participants. Patients who developed new hyperthyroidism were younger and the proportion of females was higher. They had fewer comorbidities, including diabetes (26% vs 29%, P = .121), hypertension (51% vs 58%, P < .001), coronary artery disease (17% vs 25%, P < .001), stroke (16% vs 22%, P < .001), and end-stage renal disease (ESRD) (6% vs 10%, P = .001). The CHADS2 score was lower in patients with hyperthyroidism (1.74 vs 2.05, P = .031), but there was no statistically significant difference in the CHA2DS2-VASc and HAS-BLED score. Cox regression analysis identified younger age, female gender, history of congestive heart failure, hypertension, diabetes, non-ESRD status, and lower CHADS2 score but not CHA2DS2-VASc as independent predictors of incident hyperthyroidism during follow-up. We also propose a novel, simple risk stratification score (SAD HEC2 score) with excellent predictive power for incident hyperthyroidism during follow-up.

CONCLUSION

Our results provide insight into clinical risk factors for the development of hyperthyroidism in AF patients, as identified by the novel SAD HEC2 score. AF appears to be a common precursor of hyperthyroidism.

Pulseless Electrical Activity and Perioperative Cardiac Arrest Due to Undiagnosed and Asymptomatic Hypothyroidism During Outpatient Surgery in an Adolescent

Commonly identified risk factors for perioperative cardiac arrest in pediatric-aged patients include cardiac surgery, younger age, comorbid conditions including pulmonary hypertension and cyanotic congenital heart disease, and emergency surgery. Although medication-related etiologies formerly predominated, the elimination of halothane from anesthetic care has resulted in a shift in etiology to hemodynamic events related to blood loss or hyperkalemia associated with the rapid administration of blood products. Rarely, cardiac arrest can be sudden and unexpected without an identified pre-existing etiology in an otherwise apparently healthy patient. We present an 18-year-old adolescent who experienced pulseless electrical activity (PEA) and cardiac arrest following anesthetic care for an outpatient orthopedic procedure, who was eventually diagnosed with hypothyroidism. The potential etiologies of PEA and cardiac arrest during anesthesia are reviewed, components of successful resuscitation discussed, and an outline for the investigative workup presented.

Low T3 syndrome predicts more adverse events in patients with hypertrophic cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is a common cardiac genetic disorder that clinically manifests with sudden death and progressive heart failure. Moreover, thyroid dysfunction is associated with increased cardiovascular morbidity and mortality risks. Therefore, this study aimed to clarify whether thyroid hormones could serve as an independent predictor of adverse events in patients with HCM.

METHODS

The cohort consisted of 782 patients with HCM who had thyroid hormones baseline data and were admitted to the Affiliated Hospital of Jiaxing University. Patients were divided into two groups according to serum levels of free triiodothyronine (fT3): the normal fT3 and low triiodothyronine (T3) syndrome groups. Low T3 syndrome was defined as fT3 < 2.43 pmol/L with a normal thyroid-stimulating hormone (TSH) level. Patients whose TSH levels were abnormally high or abnormally low were excluded from this study. The primary endpoint was the occurrence of sudden cardiac death (SCD) events, and the secondary endpoint was a composite of worsening heart failure (WHF) events, including heart failure death, cardiac decompensation, hospitalization for heart failure, and HCM-related stroke. The Kaplan-Meier and Cox regression were performed for the survival analysis.

RESULTS

After a median follow-up of 52 months, 75 SCD events and 134 WHF events were recorded. The Kaplan-Meier survival curves showed that the cumulative incidence of SCD events and WHF events were significantly higher in patients with low T3 syndrome (log-rank p = .02 and log-rank p = .001, respectively). Furthermore, multivariate Cox regression analysis demonstrated that low T3 syndrome is a strong predictor of SCD events and WHF events (adjusted hazard ratio [HR: 1.53, 95% confidence interval [CI]: 1.13-2.24, p < .01; HR: 3.87, 95% CI: 2.91-4.98, p < .001, respectively).

CONCLUSIONS

Low T3 syndrome is highly prevalent among patients with HCM and was independently associated with an increased risk of SCD events and WHF events. The routine assessment of serum fT3 levels may provide risk stratification in this population.

A machine learning-assisted system to predict thyrotoxicosis using patients' heart rate monitoring data: a retrospective cohort study

Previous studies have shown a correlation between resting heart rate (HR) measured by wearable devices and serum free thyroxine concentration in patients with thyroid dysfunction. We have developed a machine learning (ML)-assisted system that uses HR data collected from wearable devices to predict the occurrence of thyrotoxicosis in patients. HR monitoring data were collected using a wearable device for a period of 4 months in 175 patients with thyroid dysfunction. During this period, 3 or 4 thyroid function tests (TFTs) were performed on each patient at intervals of at least one month. The HR data collected during the 10 days prior to each TFT were paired with the corresponding TFT results, resulting in a total of 662 pairs of data. Our ML-assisted system predicted thyrotoxicosis of a patient at a given time point based on HR data and their HR-TFT data pair at another time point. Our ML-assisted system divided the 662 cases into either thyrotoxicosis and non-thyrotoxicosis and the performance was calculated based on the TFT results. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of our system for predicting thyrotoxicosis were 86.14%, 85.92%, 52.41%, and 97.18%, respectively. When subclinical thyrotoxicosis was excluded from the analysis, the sensitivity, specificity, PPV, and NPV of our system for predicting thyrotoxicosis were 86.14%, 98.28%, 94.57%, and 95.32%, respectively. Our ML-assisted system used the change in mean, relative standard deviation, skewness, and kurtosis of HR while sleeping, and the Jensen-Shannon divergence of sleep HR and TFT distribution as major parameters for predicting thyrotoxicosis. Our ML-assisted system has demonstrated reasonably accurate predictions of thyrotoxicosis in patients with thyroid dysfunction, and the accuracy could be further improved by gathering more data. This predictive system has the potential to monitor the thyroid function status of patients with thyroid dysfunction by collecting heart rate data, and to determine the optimal timing for blood tests and treatment intervention.

Carbimazole-Resistant Grave's Thyrotoxicosis is a Diagnostic and Therapeutic Dilemma, Case Report with Literature Review

Background

Carbimazole (CBZ) (or methimazole) is the most used drug inducing and maintaining remission in thyrotoxicosis, especially Grave's disease (GD). Rarely, situations arise when patients do not respond to recommended or even supratherapeutic doses of CBZ. It poses a challenge to diagnose drug resistance and ultimately manage hyperthyroidism, which can otherwise be fatal if left untreated. Propylthiouracil (PTU) has been used as an alternative in such patients amid increased side effect risks. Additionally, definitive therapy has been recommended with ablation or surgery. However, the best modality of inducing euthyroidism in drug-resistant patients is yet to be established. On literature search, twenty similar cases were found in the literature search. This study summarizes the past literature with addition of a new case of anti-thyroid drug resistant (ATDR) GD.

Case Presentation

A 34-year-old female presented with a 5-day history of progressively worsening fatigue, heat intolerance, sweating, and palpitations. She was diagnosed with GD based on her thyroid function tests (TFTs) and started on CBZ and propranolol. Despite being compliant with CBZ 20 mg once daily and then twice daily, her TFTs remained unchanged for 4 months. However, patient revisited the emergency with continued thyrotoxicosis and unchanged TFTs. Her dose was eventually increased to 20 mg thrice daily, and administration under supervision did not improve her TFTs. The patient was shifted to PTU 150 mg thrice daily with steroids, with minimal improvement. The patient eventually underwent thyroidectomy to avoid long-term PTU use.

Conclusion

ATDR GD is rare and remains a diagnostic and therapeutic challenge. Optimal management should focus on carefully excluding other possibilities and shared decision-making in its management. Most patients may require definitive therapy; hence, arrangements should be made timely with simultaneous attempts to reduce the thyrotoxic state, which otherwise poses a continued threat to patients' life with potentially serious complications.

Therapeutic Plasma Exchange in Refractory Atrial Fibrillation Secondary to a Thyroid Storm

Thyrotoxic crisis (thyroid storm) is a severe form of hyperthyroidism. It has a wide range of symptoms, including cardiovascular manifestations that can be life-threatening and require prompt management. Cardiac manifestations of thyroid storm include hypertension, tachycardia, congestive heart failure, cardiac ischemia, and atrial fibrillation. Standard therapeutic approaches of thyroid storm are based on the use of thionamides, corticosteroids, and nonselective beta-blockers to inhibit thyroid hormone synthesis and release while also blocking thyroxin's peripheral effects. This approach is an effective measure in the management of these manifestations. However, when a patient fails to respond to conventional therapy, or there is end organ damage and surgery is not feasible, therapeutic plasma exchange (TPE) is a life-saving measure. Here, we report a case of a 27-year-old female who is known to have hyperthyroidism, but she was not compliant with her medication. She presented with symptoms of hyperthyroidism and was found to have a thyroid storm with refractory atrial fibrillation. Despite the effort to control her symptoms, she developed cardiac arrest, and after 15 minutes of cardiopulmonary resuscitation, she was revived. Amiodarone, beta-blockers, and cardioversion failed to improve the patient's status, and her condition deteriorated. So, we decided to use TPE, and she received three sessions in total. After the first session of TPE, her rhythm converted to sinus rhythm, and her heart rate was controlled to less than 100 beats per minute. She showed dramatic improvement clinically and biochemically. In conclusion, cardiac complications are potentially lethal complications of thyroid storm. Prompt restoration of a normal thyroid state can reverse these complications. When conventional therapy fails to ameliorate symptoms or organ deterioration is rapid and severe, TPE can be a safe and effective measure.

The molecular evaluation of thioredoxin (TXN1 & TXN2), thioredoxin reductase 1 (TXNRd1), and oxidative stress markers in a binary rat model of hypo- and hyperthyroidism after treatment with gallic acid

Oxidative stress plays an important role in the pathology of thyroid disorders. This study examined the effect of gallic acid (GA) on the oxidative status and expression of liver antioxidant genes including thioredoxin (TXN1 & TXN2) and thioredoxin reductase1 (TXNRd1) in hypo- and hyperthyroid rat models. Forty-nine male Wistar rats were randomly assigned into seven groups as follows: control group, hypothyroid and hyperthyroid groups respectively induced by propylthiouracil and levothyroxine, hypo- and hyper thyroid-treated groups (where the groups were separately treated with 50 and 100 mg/kg of GA daily, orally). The levels of thyroid hormones and serum oxidative stress markers were evaluated after 5 weeks. The relative expression of TXN1,2 and TXNRd1 genes was measured via real-time qRT-PCR. The mean level of total antioxidant capacity (TAC), malondialdehyde, and uric acid index diminished in the hypothyroid group. Increased TAC reached almost the level of control in hypothyroid groups treated with GA. Elevation of thiol index in the hypothyroid group was observed (p < 0.01), which diminished to the control level after GA treatment. The relative expression of TXN1, TXNRd1, and TXN2 genes in the hypothyroid and hyperthyroid groups significantly increased compared to the control group (p ≥ 0.05), but in the groups treated with GA, the expression of these genes declined significantly (p ≥ 0.05). Our results indicated GA can affect the expression of TXN system genes in the rat liver. Also, the results suggest GA has a more positive effect on modulating serum oxidative parameters in hypothyroid rat models than in hyperthyroid.

The Role of Recipient Thyroid Hormone Supplementation in Primary Graft Dysfunction After Heart Transplantation: A Propensity-Adjusted Analysis

OBJECTIVES

To investigate whether recipient administration of thyroid hormone (liothyronine [T3]) is associated with reduced rates of primary graft dysfunction (PGD) after orthotopic heart transplantation.

DESIGN

Retrospective cohort study.

SETTING

Single-center, university hospital.

PARTICIPANTS

Adult patients undergoing orthotopic heart transplantation.

INTERVENTIONS

A total of 609 adult heart transplant recipients were divided into 2 cohorts: patients who did not receive T3 (no T3 group, from 2009 to 2014), and patients who received T3 (T3 group, from 2015 to 2019). Propensity-adjusted logistic regression was performed to assess the association between T3 supplementation and PGD.

MEASUREMENTS AND MAIN RESULTS

After applying exclusion criteria and propensity-score analysis, the final cohort included 461 patients. The incidence of PGD was not significantly different between the groups (33.9% no T3 group v 40.8% T3 group; p = 0.32). Mortality at 30 days (3% no T3 group v 2% T3 group; p = 0.53) and 1 year (10% no T3 group v 12% T3 group; p = 0.26) were also not significantly different. When assessing the severity of PGD, there were no differences in the groups' rates of moderate PGD (not requiring mechanical circulatory support other than an intra-aortic balloon pump) or severe PGD (requiring mechanical circulatory support other than an intra-aortic balloon pump). However, segmented time regression analysis revealed that patients in the T3 group were less likely to develop severe PGD.

CONCLUSIONS

These findings indicated that recipient single-dose thyroid hormone administration may not protect against the development of PGD, but may attenuate the severity of PGD.

Clinical features and long-term survival in idiopathic pulmonary arterial hypertension with thyroid dysfunction: insights from a national multicentre prospective study

Background

Our objective was to clarify the characteristics and long-term survival of idiopathic pulmonary arterial hypertension (IPAH) patients with thyroid dysfunction and compare them with IPAH without thyroid dysfunction.

Methods

A retrospective analysis was conducted using prospectively collected data. IPAH patients with thyroid dysfunction at baseline were included. Patients with other subgroups of PAH and Group 2-5 pulmonary hypertension were excluded. IPAH patients with euthyroid function were matched 1:1 to IPAH patients with thyroid dysfunction by age and sex.

Results

In total, 148 IPAH patients with thyroid dysfunction were included. Patients with hyperthyroidism, hypothyroidism, subclinical hyperthyroidism and subclinical hypothyroidism accounted for 16.2%, 18.9%, 8.1% and 56.8%, respectively. IPAH patients with hyperthyroidism showed the highest mixed venous oxygen saturation (SvO2) and the lowest pulmonary vascular resistance (PVR) at baseline among subgroups, while patients with subclinical hypothyroidism had the lowest SvO2 and highest PVR (p<0.05). Compared with IPAH without thyroid dysfunction, patients with hyperthyroidism (9.14 versus 13.86 WU; p<0.05) and hypothyroidism (10.70 versus 13.86 WU; p<0.05) showed significantly lower PVR. The haemodynamic profiles of patients with subclinical hypothyroidism were similar to IPAH with euthyroid function except for lower right atrial pressure (6 versus 8 mmHg; p=0.009). The long-term survival of patients with clinical thyroid dysfunction was better than IPAH without thyroid dysfunction, while that of those with subclinical diseases was comparable to the latter, even after adjusting for baseline haemodynamics and treatment.

Conclusion

IPAH patients with clinical hyper- and hypothyroidism had better haemodynamics and survival than those without thyroid dysfunction, while patients with subclinical hypothyroidism had similar haemodynamics and survival profiles to the latter.

Hoffman syndrome with the classic sign of myoedema and an unusual finding of systolic heart failure

A man in his 20s presented with a 6-year history of calf muscle hypertrophy, proximal muscle weakness and muscle cramps. Along with this, he also had patchy hair loss, facial puffiness and slurring of speech. On examination, he had mild symmetrical proximal muscle weakness, a delayed relaxation phase of his deep tendon reflexes and a rare neurological sign of myoedema. His laboratory investigations revealed elevated thyroid-stimulating hormone levels with high creatine kinase levels, and an echocardiogram showed left ventricular systolic dysfunction. He was diagnosed with Hoffman syndrome, a rare pseudohypertrophic myopathy associated with severe and prolonged hypothyroidism. He had an excellent response to thyroid hormone replacement.

High Time to Consider the Role of Thyroid Function in Single Ventricle Heart Disease

Herein we respond to the controversial United States Food and Drug Administration (FDA) recommendation to perform thyroid function testing in children up to 3 years of age within 3 weeks of exposure to iodinated contrast media (ICM). Considering the many effects of thyroid hormone on the cardiovascular system, the increased risk of thyroid disease in patients with congenital heart disease, the hemodynamic consequences of the Fontan circulation on the thyroid gland, and the potential clinical significance of subclinical hypothyroidism, we share our perspective that the cardiovascular effects of thyroid hormone may carry more influence for patients with single ventricle heart disease. In our opinion, the FDA statement prompts us to consider routine thyroid hormone surveillance testing in the long-term management of patients with single ventricle heart disease.

Subclinical Hypothyroidism, Kidney, and Heart from Normal to Uremic Milieu

Thyroid hormone (TH) imbalances, particularly subclinical hypothyroidism (SCHT), are associated with chronic kidney disease (CKD) and end-stage kidney disease (ESKD). SCHT is more prevalent in CKD and ESKD patients than in the general population, and this condition increases the risk of cardiovascular disease (CVD) morbidity and mortality. The risk of CVD is higher in CKD and ESKD patients compared with the general population. Traditional and nontraditional risk factors, including TH abnormalities, contribute to the high CVD burden in CKD and ESKD patients. The review discusses the link between CKD and hypothyroidism, with a focus on SCHT, and the mechanisms that lead to CVD burden.

Risk factors for cardiogenic shock in thyroid storm: a retrospective and case-series study

Aim: Thyroid storm (TS) occurs in 10% of thyrotoxicosis patients and 1% of TS patients experience cardiogenic shock (CS), which is associated with poor prognosis. Methods: This is a single institution, retrospective study in which 56 patients with TS were evaluated. Results: BMI (p = 0.002), history of heart failure (OR 8.33 [1.91, 36.28]; p = 0.004), pro-BNP elevation (p = 0.04), chest x-ray showing interstitial edema (OR 3.33 [1.48, 7.52]; p = 0.01) and Burch-Wartofsky score (62.5 vs 40; p = 0.004) showed association with CS. CS patients had increased length of stay (16.5 vs 4 days; p = 0.01) and higher in-hospital mortality (OR 24.5 [2.90, 207.29]; p < 0.001). Conclusion: These risk factors are useful to risk stratify TS patients on admission, institute therapy in a timely manner and decrease mortality.

The EANM guideline on radioiodine therapy of benign thyroid disease

This document provides the new EANM guideline on radioiodine therapy of benign thyroid disease. Its aim is to guide nuclear medicine physicians, endocrinologists, and practitioners in the selection of patients for radioiodine therapy. Its recommendations on patients' preparation, empiric and dosimetric therapeutic approaches, applied radioiodine activity, radiation protection requirements, and patients follow-up after administration of radioiodine therapy are extensively discussed.

Effect of different iodide intake during pregnancy and lactation on thyroid and cardiovascular function in maternal and offspring rats

OBJECTIVE

We aimed to investigate the impact of different iodide intake during pregnancy and lactation on iodine concentration in urine and serum, fatty acid metabolism, thyroid and cardiovascular function in maternal and offspring rats.

METHODS

Pregnant rats were randomly assigned to four groups: normal adult iodide intake (NAI, 7.5 μg/d), normal pregnant iodide intake (NPI, 12.5 μg/d), 5 times (5 HI, 62.5 μg/d) and 10 times higher-than-normal pregnant iodide intake (10 HI, 125 μg/d). The maternal rats were continuously administered potassium iodide until postnatal day 16 (PN16). Thyroid function was measured by enzyme-linked immunosorbent assay (ELISA). The iodine concentration in urine and serum were detected by inductively coupled plasma mass spectrometry (ICP-MS). The messenger ribonucleic acid (mRNA) expressions of Krüppel-like factor 9 (KLF9) and thioredoxin reductase 2 (Txnrd2) were measured using quantitative real-time polymerase chain reaction (RT-qPCR). Characteristic distribution of KLF9 expression and its interaction with TRβ was assessed by immunohistochemical and immunofluorescence staining. Serum fatty acids were analyzed by Liquid Chromatography-Mass Spectrometry (LC-MS). Cardiac function and blood pressure were measured by echocardiography and a non-invasive tail-cuff system.

RESULTS

High iodide intake (5 HI and 10 HI) during pregnancy and lactation results in increased urinary iodine concentration (UIC), serum total iodine concentration (STIC) and serum non-protein-bound iodine concentration (SNBIC) in both maternal and offspring rats, along with significantly increased FT3 and its target gene expression of KLF9. In maternal rats of both 5 HI and 10 HI groups, systolic blood pressure (SBP) was significantly higher, the increased SBP was significantly correlated with the increased UIC (r = 0.968, p = 0.002; r = 0.844, p = 0.035), KLF9 (r = 0.935, p = 0.006; r = 0.954, p = 0.003) and the decreased Txnrd2 (r = -0.909, p = 0.012; r = -0.912, p = 0.011). In maternal rats of 10 HI group, cardiac hyperfunction with increased LVEF, LVFS and decreased LVESD were observed. The increased LVEF and decreased LVESD were significantly correlated with UIC, STIC and SNBIC (r = 0.976, p = 0.001; r = 0.945, p = 0.005; r = 0.953, p = 0.003; r = -0.917, p = 0.01; r = -0.859, p = 0.028; r = -0.847, p = 0.033), LVEF, LVFS and LVESD were significant correlated with KLF9 (r = 0.950, p = 0.004; r = 0.963, p = 0.002; r = -0.990, p = 0.0002) and Txnrd2 expression (r = -0.979, p = 0.001; r = -0.915, p = 0.01; r = 0.933, p = 0.007), and the decreased LVESD was correlated with decreased epoxyeicosatrienoic acid (EET) metabolites: 5,6-EET, 8,9-DHET and 11,12-DHET (r = 0.999, p = 0.034; r = 1.000, p = 0.017; r = 1.000, p = 0.017). While in offspring rats, no significant change in SBP and cardiac function was found. STIC and SNBIC were much lower than those in maternal rats, and eicosapentaenoic acid (EPA) metabolites (9-HEPE, 15-HEPE and 14,15 DiHETE) were significantly increased.

CONCLUSION

In addition to thyroid hormones, STIC, SNBIC, KLF9, Txnrd2, EET and EPA metabolites might be promising biomarkers in high iodide intake-induced thyroid and cardiovascular function.

Increased 10-year cardiovascular disease risk in depressed patients with coexisting subclinical hypothyroidism

Purpose

The prevalence of depressive disorder (DD) and subclinical hypothyroidism (SH) was almost twofold higher in women compared with men, both of which are confirmed to be related to cardiovascular disease (CVD) risk. The current study aimed to identify the prevalence of CVD risk factors and evaluate the 10-year CVD risk in female depressed patients with and without comorbid SH.

Methods

We recruited 1744 female inpatients with a diagnosis of DD. Venous blood samples were taken from all patients for lipid and thyroid hormones. Framingham Risk Score (FRS) was used to estimate the 10-year CVD risk.

Results

Female depressed patients with SH had increased BMI, higher Hamilton Anxiety Scale (HAMA) scores, higher LDL-C, TC, UA, and a higher 10-year CVD risk than euthyroid DD groups. Serum TSH levels and HAMA scores were critical predictive variables for 10-year CVD risk in female depressed patients with comorbid SH.

Conclusion

Our study suggests that female depressed patients with SH have a high 10-year CVD risk. Serum TSH levels and HAMA scores may be helpful to predict cardiovascular risk in female patients with SH. The increased CVD risk in female depressed patients with comorbid SH requires more attention from researchers and clinicians.