Thyroid hormone and atherosclerosis

Predictive Effect of FT3 Within the Euthyroid Range on LDL-C in Patients With Type 2 Diabetes: A Cross-Sectional Analysis of Inpatients in China

Evidence regarding the relationship between free triiodothyronine (FT3) and low-density lipoprotein cholesterol (LDL-C) remains limited. This study aimed to evaluate the association between FT3 and LDL-C levels in patients with type 2 diabetes mellitus (T2DM) who exhibit normal thyroid function. Between June 2022 and October 2023, a total of 3011 inpatients with T2DM and euthyroid status were continuously and non-selectively recruited from a Chinese hospital. The average age of the included individuals was 56.92 ± 12.56 years, with 1430 (47.49%) males. The mean FT3 concentration was 4.35 ± 0.56 pmol/L. A logistic regression model was applied to analyse the relationship between the FT3 and LDL-C levels, while smooth curve fitting was employed to investigate potential nonlinear associations between these variables. This study demonstrated a positive correlation (0.05 [95% CI: 0.02-0.07; p = 0.0018]) and nonlinear relationship (p = 0.0014) between FT3 and LDL-C levels in Chinese patients with diabetes. Specifically, when FT3 was below 4.28 pmol/L, LDL-C levels increased alongside rising FT3 concentration. However, when FT3 reached or exceeded 4.28 pmol/L, LDL-C levels plateaued and tended to stabilise. These findings suggest that maintaining FT3 within the range of 2.76 to 4.28 pmol/L may be most beneficial for mitigating the progression of cardiovascular disease in patients with T2DM. Our research is important for identifying the optimal FT3 range to delay the progression of cardiovascular disease in patients with T2DM. These findings provide valuable insights to guide clinicians in preventing and managing cardiovascular disease in this population.

Association between thyroid hormone sensitivity and carotid plaque risk: a health examination cohort-based study

Introduction

The involvement of thyroid hormone in cardiovascular disease remains debated. The aim of our research was to ascertain whether thyroid hormone sensitivity indices are related to carotid plaque (CAP) risk in the general population.

Methods

We recruited 5,360 participants for health examinations to explore the correlation between thyroid hormone sensitivity indices and CAP risk. We then compared baseline characteristics of participants with CAP to those without CAP based on multivariate logistic regression analysis. Additionally, we conducted subgroup analyses stratified by gender and age to further elucidate this relationship.

Results

Among the 5,360 participants, 1,055 (19.7%) were diagnosed with CAP. After adjusting for various confounding factors, our results showed a positive association between CAP risk and the indices (TFQI, PTFQI, TSHI, and TT4RI). Conversely, the FT3/FT4 ratio showed a negative correlation with CAP risk. Sex-based subgroup analysis revealed a stronger correlation between thyroid hormone sensitivity and CAP in females compared to males. In the age subgroup, the significant association was observed in older individuals (age >60) compared to middle-aged participants (age ≤60).

Conclusion

Our study suggests a significant correlation between thyroid hormone sensitivity and CAP, particularly in females and participants over the age of 60.

Increased thyroid stimulating hormone (TSH) as a possible risk factor for atherosclerosis in subclinical hypothyroidism

Primary hypothyroidism (PHT) is associated with an increased risk for the development of atherosclerosis (AS) and other cardiovascular disorders. PHT induces atherosclerosis (AS) through the induction of endothelial dysfunction, and insulin resistance (IR). PHT promotes vasoconstriction and the development of hypertension. However, patients with subclinical PHT with normal thyroid hormones (THs) are also at risk for cardiovascular complications. In subclinical PHT, increasing thyroid stimulating hormone (TSH) levels could be one of the causative factors intricate in the progression of cardiovascular complications including AS. Nevertheless, the mechanistic role of PHT in AS has not been fully clarified in relation to increased TSH. Therefore, in this review, we discuss the association between increased TSH and AS, and how increased TSH may be involved in the pathogenesis of AS. In addition, we also discuss how L-thyroxine treatment affects the development of AS.

Higher Levels of Plasma Fetuin-A, Nrf2, and Cytokeratin 18 in Patients with Hashimoto's Disease

Objectives

Fetuin-A is a protein that exhibits proatherogenic, pro-inflammatory, and anti-inflammatory effects with increased insulin resistance and adipocyte dysfunction. The nuclear factor erythroid 2-related factor (Nrf2) is a transcription factor that is crucial for protecting cells against oxidative damage. As a cell death product, cytokeratin 18 (CK18) levels increase during necrosis and apoptosis of both normal and tumor cells. We analyzed the plasma levels of three biomarkers based on the hypothesis that they might be related to some pathophysiological pathways in Hashimoto's disease.

Methods

We compared 34 female patients with overt hypothyroidism due to Hashimoto's disease (Group 1) with 34 age-matched healthy females (Group 2). For comparison, plasma levels of thyroid-stimulating hormone (TSH), fetuin-A, Nrf2, and CK18 were measured in all participants.

Results

In group 1, the mean TSH levels (31.4±15.3) were significantly higher than those in group 2 (2.6±1.0) (p<0.001). The levels of mean fetuin-A (606.7±34.2) and Nrf2 (1.3±0.6) were found to be significantly higher in group 1 than in group 2 (440.0±34.2 vs. 0.7±0.2) (p<0.001 for both). CK18 levels in group 1 (0.36±0.13) were also significantly higher than in group 2 (0.26±0.16) (p=0.020). A significant correlation was observed between TSH levels and fetuin-A (r=0.401, p=0.001).

Conclusion

Increased levels of fetuin-A, Nrf2, and CK18 may be a consequence or cause of the pathophysiological pathways of Hashimoto's disease. The clinical significance of increased levels of these biomarkers requires further investigation.

The Impact of Laparoscopic Sleeve Gastrectomy on Thyroid Functions in Egyptian Patients with Obesity

BACKGROUND

Sleeve gastrectomy (SG) continues to be one of the most popular bariatric procedures all over the world. Thyroid-stimulating hormone (TSH) frequently shows a slight elevation in patients with obesity. The effect of SG on thyroid hormones has been rarely investigated.

AIM OF THE STUDY

This study aimed to assess the short-term effect of SG on thyroid functions in Egyptian patients with morbid obesity and the potential predictors of the postoperative thyroid functions.

PATIENTS AND METHODS

This study included patients undergoing SG at kasr al ainy hospitals. The patients underwent preoperative 3-, 6-, and 12-month postoperative analyses of the thyroid functions and other biochemical markers.

RESULTS

The study included 106 patients who showed significant improvement in thyroid functions at the follow-up assessment. Twelve-month TSH positively correlated with the 12-month measures of LDL and HbA1c. TSH change at 12-month follow-up (TSH) was inversely correlated to 12-month BMI and positively correlated to preoperative TSH and 12-month percentage of total weight loss (TWL%). Univariable linear regression analysis demonstrated that preoperative TSH (p < 0.001), 12-month TWL% (p = 0.042), 12-month HbA1c (p = 0.001), and 12-month LDL (p = 0.049) were significant predictors for the 12-month TSH levels. Multivariable analysis showed that only preoperative TSH levels (p < 0.001) and 12-month HbA1c levels (p = 0.021) could affect the 12-month TSH levels.

CONCLUSION

The current study supports the evidence of thyroid function improvement after sleeve gastrectomy. This improvement was affected by the amount of weight loss after surgery.

Transiently impaired endothelial function during thyroid hormone withdrawal in differentiated thyroid cancer patients

Purpose

Endothelial dysfunction, which was associated with chronic hypothyroidism, was an early event in atherosclerosis. Whether short-term hypothyroidism following thyroxine withdrawal during radioiodine (RAI) therapy was associated with endothelial dysfunction in patients with differentiated thyroid cancer (DTC) was unclear. Aim of the study was to assess whether short-term hypothyroidism could impair endothelial function and the accompanied metabolic changes in the whole process of RAI therapy.

Methods

We recruited fifty-one patients who underwent total thyroidectomy surgery and would accept RAI therapy for DTC. We analyzed thyroid function, endothelial function and serum lipids levels of the patients at three time points: the day before thyroxine withdrawal(P₁), the day before ¹³¹I administration(P₂) and 4-6 weeks after RAI therapy(P₃). A high-resolution ultrasound named flow-mediated dilation (FMD) was used to measure endothelial function of the patients.

Results

We analyzed the changes of FMD, thyroid function and lipids at three time points. FMD(P₂) decreased significantly compared to FMD(P₁) (P₁vsP₂, 8.05 ± 1.55vs 7.26 ± 1.50, p<0.001). There was no significant difference between FMD(P₃) and FMD(P₁) after restoring TSH (thyroid stimulating hormone) suppression therapy (P₁ vs P3, 8.05 ± 1.55 vs 7.79 ± 1.38, p=0.146). Among all parameters, the change of low-density lipoprotein (ΔLDL) was the only factor correlated negatively with the change of FMD (ΔFMD) throughout the RAI therapy process (P_1-2, r=-0.326, p=0.020; P_2-3, r=-0.306, p=0.029).

Conclusion

Endothelial function was transiently impaired in DTC patients at short-term hypothyroidism state during the RAI therapy, and immediately returned to the initial state after restoring TSH suppression therapy.

Association of LncRNA-PAX8-AS1 and LAIR-2 polymorphisms along with their expression with clinical and subclinical hypothyroidism

The genetic and epigenetic architecture of clinical and subclinical hypothyroidism remains unclear. We investigated the impact of long noncoding RNA (LncRNA)-PAX8-AS1 and LAIR-2 genetic variants on the susceptibility to clinical and subclinical hypothyroidism, their influence on LncRNA-PAX8-AS1 and LAIR-2 expression and their potential as hypothyroid biomarkers. Hundred clinical hypothyroid patients, 110 subclinical hypothyroid patients, and 95 healthy controls were enrolled. Gene expression analysis and genotyping were performed by qPCR. LAIR-2 protein, a proinflammatory mediator, was tested by ELISA. Serum LncRNA-PAX8-AS1 was downregulated, whereas LAIR-2 mRNA and protein levels were upregulated in clinical and subclinical hypothyroid patients compared to healthy controls. LncRNA-PAX8-AS1 rs4848320 and rs1110839 were associated with increased risk of clinical hypothyroidism. Interestingly, both SNPs were associated with differential expression of serum LncRNA-PAX8-AS1 among clinical hypothyroid patients. LAIR-2 rs2287828 was associated with elevated risk of both clinical and subclinical hypothyroidism. Harboring the rs2287828 T allele augmented the LAIR-2 mRNA expression among clinical hypothyroid patients, while elevated both LAIR-2 mRNA and protein levels in subclinical hypothyroid patients. The rs4848320-rs1110839-rs2287828 TTT, CTT, and CGT haplotypes were associated with increased hypothyroid risk. Surprisingly, serum LncRNA-PAX8-AS1 and LAIR-2 mRNA expression demonstrated superior diagnostic accuracy for clinical hypothyroidism and turned out as independent predictors in the multivariate analysis. Conclusively, LncRNA-PAX8-AS1 and LAIR-2 genetic variants are novel genetic biomarkers of hypothyroidism that could alter the LncRNA-PAX8-AS1 and LAIR-2 expression. LncRNA-PAX8-AS1 and LAIR-2 expression profiles have the potential as effective diagnostic and prognostic indicators of hypothyroidism.

Mechanisms and Management of Thyroid Disease and Atrial Fibrillation: Impact of Atrial Electrical Remodeling and Cardiac Fibrosis

Atrial fibrillation (AF) is the most common cardiac arrhythmia associated with increased cardiovascular morbidity and mortality. The pathophysiology of AF is characterized by electrical and structural remodeling occurring in the atrial myocardium. As a source of production of various hormones such as angiotensin-2, calcitonin, and atrial natriuretic peptide, the atria are a target for endocrine regulation. Studies have shown that disorders associated with endocrine dysregulation are potential underlying causes of AF. The thyroid gland is an endocrine organ that secretes three hormones: triiodothyronine (T3), thyroxine (T4) and calcitonin. Thyroid dysregulation affects the cardiovascular system. Although there is a well-established relationship between thyroid disease (especially hyperthyroidism) and AF, the underlying biochemical mechanisms leading to atrial fibrosis and atrial arrhythmias are poorly understood in thyrotoxicosis. Various animal models and cellular studies demonstrated that thyroid hormones are involved in promoting AF substrate. This review explores the recent clinical and experimental evidence of the association between thyroid disease and AF. We highlight the current knowledge on the potential mechanisms underlying the pathophysiological impact of thyroid hormones T3 and T4 dysregulation, in the development of the atrial arrhythmogenic substrate. Finally, we review the available therapeutic strategies to treat AF in the context of thyroid disease.

Dog models of human atherosclerotic cardiovascular diseases

Cardiovascular diseases (CVD) are one of the leading causes of death worldwide. Eighty-five percent of CVD-associated deaths are due to heart attacks and stroke. Atherosclerosis leads to heart attack and stroke through a slow progression of lesion formation and luminal narrowing of arteries. Dogs are similar to humans in terms of their cardiovascular physiology, size, and anatomy. Dog models have been developed to recapitulate the complex phenotype of human patients and understand the underlying mechanism of CVD. Different methods, including high-fat, high-cholesterol diet and genetic modification, have been used to generate dog models of human CVD. Remarkably, the location and severity of atherosclerotic lesions in the coronary arteries and branches of the carotid arteries of dog models closely resemble those of human CVD patients. Overt clinical manifestations such as stroke caused by plaque rupture and thrombosis were observed in dog models. Thus, dog models can help define the pathophysiological mechanisms of atherosclerosis and develop potential strategy for preventing and treating CVD. In this review, we summarize the progress in generating and characterizing canine models to investigate CVD and discuss the advantages and limitations of canine CVD models.

Association of methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms (C677T and A1298C) with thyroid dysfunction: A meta-analysis and trial sequential analysis

Recent studies have shown that two common methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms (C677T and A1298C) might correlate with thyroid dysfunction, but the results remain inconsistent. We carried out a meta-analysis aiming to assess the relationship of both polymorphisms with thyroid dysfunction. The PubMed, EMBASE, CNKI (China National Knowledge Infrastructure), CBMdisc (China Biology Medicine disc), WeiPu and Wanfang databases were searched up to September 2021. Case-control and cohort studies on MTHFR polymorphism and thyroid dysfunction were identified. Eight studies from six publications were finally included in our meta-analysis, including 817 patients and 566 controls. After pooled analysis, we found that the MTHFR C677T polymorphism was associated with an increased risk of hypothyroidism (TT vs. CC+CT/recessive model: OR = 2.07, 95% CI: 1.02-4.20, P = 0.04; TT vs. CC/homozygote model: OR = 2.35, 95% CI: 1.13-4.86, P = 0.02), while trial sequential analysis (TSA) revealed that it could be a false positive result. The MTHFR A1298C polymorphism was related to a decreased risk of hypothyroidism (C vs. A/allele model: OR = 0.63, 95% CI: 0.44-0.92, P = 0.02; CC vs. AC+AA/recessive model: OR = 0.42, 95% CI: 0.22-0.79, P = 0.007; CC vs. AA/homozygote model: OR = 0.43, 95% CI: 0.25-0.85, P = 0.02), which was conclusive according to TSA. The results of this meta-analysis suggest that MTHFR A1298C seems to be a protective factor for hypothyroidism, while the MTHFR C677T polymorphism may be a risk factor. However, more well-designed studies with larger sample sizes are needed to obtain more reliable results of the association between the MTHFR C677T polymorphism and hypothyroidism.

Thyroid Function Before and After Laparoscopic Sleeve Gastrectomy in Patients with Obesity

BACKGROUND

Effect of laparoscopic sleeve gastrectomy (LSG) on thyroid function of patients with obesity remains unclear. The aim of this study was to evaluate the changes in thyroid function before and after LSG in patients with obesity.

METHODS

Data was retrieved from a retrospectively collected database of patients with morbid obesity and normal thyroid function who received LSG. At 12 months after surgery, changes of thyroid-stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), and intact parathyroid hormone (iPTH) were evaluated. In addition, the correlation between thyroid hormone levels and body mass index (BMI) and other metabolic indicators and anthropometric parameters were analyzed.

RESULTS

Eighty-five patients were included in the study. The concentrations of FT3 (5.7 ± 0.7 vs 5.1 ± 0.6, p < 0.001) and TSH (2.2 ± 1.0 vs 1.9 ± 0.9, p = 0.002) significantly decreased 12 months postsurgery, while mean FT4 levels increased from12.0 ± 1.9 vs 12.4 ± 2.0 pmol/L (p = 0.013). Furthermore, mean iPTH decreased from 53.3 ± 48.3 to 38.7 ± 13.2 pg/mL (p = 0.011). Multiple stepwise regression analysis showed that changes in LDL levels were an independent factor contributing to changes in TSH levels (β = 0.362, p = 0.001). Moreover, TSH did not correlate with BMI.

CONCLUSIONS

In this study, FT3, TSH, and iPTH were decreased in euthyroid patients with obesity after LSG, while FT4 was significantly increased. Changes in TSH were positively correlated with LDL, but no statistically significant correlation was found with BMI. Additionally, FT3, FT4, and iPTH were correlated with VB12, age, and BMI, respectively.

A systematic review on Zhilong Huoxue Tongyu capsule in treating cardiovascular and cerebrovascular diseases: Pharmacological actions, molecular mechanisms and clinical outcomes

ETHNOPHARMACOLOGICAL RELEVANCE

Cardiovascular and cerebrovascular diseases have become a severe threat for human health worldwide, however, optimal therapeutic options are still developed. Zhilong Huoxue Tongyu capsule (ZL capsule) is mainly composed of Astragalus membranaceus, Leech, Earthworm, Cinnamomum cassia and Sargentodoxa cuneata, having functions of replenishing qi and activating blood, dispelling wind and reducing phlegm. It is an expanded application on the basis of traditional uses of above TCMs, acquiring a satisfactory curative effect on cardiovascular and cerebrovascular diseases over twenty years.

AIM OF THE STUDY

To comprehensively summarize the main components of ZL capsule, understand the mechanisms of ZL capsule, and conclude clinical regimens of ZL capsule for cardiovascular and cerebrovascular diseases.

MATERIALS AND METHODS

We selected network pharmacology technology to analyze main active compounds and predict underlying mechanism of ZL capsule against atherosclerosis. Molecular docking was performed to simulate the interaction pattern between the active components of ZL capsule and putative targets. Further, PubMed, Web of Science, China National Knowledge Infrastructure and Google Scholar were used to search literatures, with the key words of "Zhilong Huoxue Tongyu capsule", "cardiovascular and cerebrovascular diseases", "atherosclerosis", "clinical study" and their combinations, mainly from 2000 to 2020.

RESULTS

Both network pharmacology analysis, molecular docking and animal experiments studies confirmed that mechanisms of ZL capsule plays the role of anti-inflammatory, anti-apoptosis and promoting angiogenesis in treating cardiovascular and cerebrovascular diseases by multi-components acting on multi-targets via multi-pathways. Over 1000 clinical cases were benefited from the treatment of ZL capsule, suggesting a holistic concept of "the same therapy for different myocardial and cerebral diseases".

CONCLUSIONS

For the first time, this systematic review may supply meaningful information for further studies to explore material basis and pharmacodynamics of ZL capsule and also provide a basis for sharing the "Chinese patent medicine" for cardiovascular and cerebrovascular diseases.

Interactions among thyroid hormones and serum lipid levels in association with PCB exposure in the Mohawk Akwesasne population

Alterations in thyroid function and serum lipid levels were assessed in relation to exposure to polychlorinated biphenyls (PCBs) and three chlorinated pesticides (DDE, hexachorobenzene and mirex) in a sample of Akwesasne Mohawk adults. This population is highly exposed to PCBs because of living in close proximity to three aluminum foundries that used PCBs as hydraulic fluids, which then contaminated local fish, wildlife, water, air and soils. The goal was to assess interactions between thyroid function (TSH, T3, T4 and fT4) and serum lipids (cholesterol, triglycerides and total serum lipids) in relation to concentrations of 101 PCB congeners and three chlorinated pesticides. Previous studies in this population have shown that elevated concentrations of PCBs resulted in suppression of thyroid function in adolescents, and increased risk of clinical hypothyroidism in adults, as well as an elevation in serum lipids. However in adjusted analyses of PCB concentrations of 703 adults we find only small and inconsistent associations between serum PCB levels and thyroid function. The most striking observations were strong significant positive associations between TSH and T3 with serum lipids and a negative association with fT4 in women. Because elevated serum lipids increase risks of other diseases the respective roles of thyroid hormones and PCBs in regulation of serum lipids requires additional study.

A network pharmacology analysis on drug-like compounds from Ganoderma lucidum for alleviation of atherosclerosis

Ganoderma lucidum (GL) is known as a potent alleviator against chronic inflammatory disease like atherosclerosis (AS), but its mechanisms against AS have not been unveiled. This research aimed to identify the key compounds(s) and mechanism(s) of GL against AS through network pharmacology. The compounds from GL were identified by gas chromatography-mass spectrum (GC-MS), and SwissADME screened their physicochemical properties. Then, the target(s) associated with the screened compound(s) or AS related targets were identified by public databases, and we selected the overlapping targets using a Venn diagram. The networks between overlapping targets and compounds were visualized, constructed, and analyzed by RStudio. Finally, we performed a molecular docking test (MDT) to explore key target(s), compound(s), on AutoDockVina. A total of 35 compounds in GL were detected via GC-MS, and 34 compounds (accepted by Lipinski's rule) were selected as drug-like compounds (DLCs). A total of 34 compounds were connected to the number of 785 targets, and DisGeNET and Online Mendelian Inheritance in Man (OMIM) identified 2,606 AS-related targets. The final 98 overlapping targets were extracted between the compounds-targets and AS-related targets. On Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, the number of 27 signaling pathways were sorted out, and a hub signaling pathway (MAPK signaling pathway), a core gene (PRKCA), and a key compound (Benzamide, 4-acetyl-N-[2,6-dimethylphenyl]) were selected among the 27 signaling pathways via MDT. Overall, we found that the identified 3 DLCs from GL have potent anti-inflammatory efficacy, improving AS by inactivating the MAPK signaling pathway. PRACTICAL APPLICATIONS: Ganoderma lucidum (GL) has been used as a medicinal or edible mushroom for chronic inflammatory patients: diabetes mellitus and dyslipidemia, especially atherosclerosis (AS). Until now, the majority of mushroom research has been implemented regarding β-glucan derivatives with very hydrophilic physicochemical properties. It implies that β-glucan or its derivatives have poor bioavailability. Hence, we have involved GC-MS in identifying lipophilic compounds from GL, which filtered them in silico to sort drug-like compounds (DLCs). Then, we retrieved targets associated with the DLCs, and identified a key signaling pathway, key targets, and key compounds against AS. In this paper, we utilized bioinformatics and network pharmacology theory to understand the uncovered pharmacological mechanism of GL on AS. To sum things up, our analysis elucidates the relationships between signaling pathways, targets, and compounds in GL. Ultimately, this work provides biochemical evidence to identify the therapeutic effect of GL on AS, and a scientific basis for deciphering the key mechanism on DLCs of GL against AS.

Free Triiodothyronine Connected With Metabolic Changes in Patients With Coronary Artery Disease by Interacting With Other Functional Indicators

This study aims to evaluate the association between free triiodothyronine (FT3) and outcomes of coronary artery disease (CAD) patients, as well as to assess the predictive power of FT3 and related functional markers from the perspective of potential mechanism. A total of 5104 CAD patients with an average follow-up of three years were enrolled into our study. Multivariate Cox regression was used to evaluate the associations between FT3, FT4 (free thyroxin), FT3/FT4 and death, MACE. We developed and validated an age, biomarker, and clinical history (ABC) model based on FT3 indicators to predict the prognosis of patients with CAD. In the multivariable Cox proportional hazards model, FT3 and FT3/FT4 were independent predictors of mortality (Adjusted HR = 0.624, 95% CI = 0.486–0.801; adjusted HR = 0.011, 95% CI = 0.002–0.07, respectively). Meanwhile, emerging markers pre-brain natriuretic peptide, fibrinogen, and albumin levels are significantly associated with low FT3 (p < 0.001). The new risk death score based on biomarkers can be used to well predict the outcomes of CAD patients (C index of 0.764, 95% CI = 0.731–0.797). Overall, our findings suggest that low levels of FT3 and FT3/FT4 are independent predictors of death and MACE risk in CAD patients. Besides, the prognostic model based on FT3 provides a useful tool for the death risk stratification of CAD patients.

Common Electrolyte and Metabolic Abnormalities Among Thyroid Patients

The prevalence of thyroid diseases is high in the general population and causes serious abnormalities and disorders that can affect the quality of life. Many complications can result from poor or inappropriate management of the disease, leading to serious cardiovascular and metabolic complications. In the present review study, we aim to discuss the effect of thyroid diseases on metabolic and electrolyte abnormalities and the potential correlation with some common disorders. Evidence from previous studies has demonstrated that thyroid dysfunctions hugely affect the metabolism of glucose in the bodies of the affected patients, which can lead to the development of both type 1 and 2 diabetes mellitus (DM). Hyperthyroidism can lead to the development of impaired glucose tolerance and secondary diabetes mellitus. These include an increased glycogenolysis and gluconeogenesis process, increased intestinal absorption of glucose, and secondary ketogenesis and lipolysis, which will subsequently affect the functions of the insulin-secreting cells of the pancreas. Evidence showed that thyroid diseases are associated with the development of obesity and metabolic syndrome, and the management for these modalities should involve prior management of underlying thyroid diseases. Efforts should be made to adequately manage these cases with concomitant approaches to achieve the best clinical outcomes.

Supplement therapy with apelin for improving the TSH level and lipid disorders in PTU-induced hypothyroid rats

Hyperlipidemia is a common metabolic disorder in the general population, which may arise in hypothyroidism. Apelin is an endogenous ligand that acts as an adiponectin, and is involved in energy storage and metabolism. This study evaluated the effects of apelin administration per se or in combination with T4 on the serum level of thyroid-stimulating hormone (TSH), body weight, and lipid profile, along with the serum level of apelin, and its mRNA expression in heart, in 6-propyl-2-thiouracil (PTU)-induced hypothyroid rats. Male Wistar rats were assigned to five different groups: control, H (hypothyroid), H+A, H+T, and H+A+T. All groups except the control one received PTU (0.05%) in the drinking water for 6 weeks. In addition to PTU, the H+A, H+T, and H+A+T groups received apelin (200 μg/kg/day, i.p.), l-thyroxin (T4) (20 μg/kg/day, via gavage tube), and apelin+T4 during the last 14 days of the trial, respectively. A combined application of T4 and apelin in the H+A+T group effectively diminished mean TSH level, low-density-lipoprotein cholesterol/high-density-lipoprotein cholesterol ratio, and atherogenic index in these animals when compared with these values for the H group. Coadministration of apelin with T4 may offer valuable therapeutic benefits, specifically lowering blood plasma TSH, lipid disorder, and atherosclerosis biomarkers in PTU-induced hypothyroid rats.

The Differential Effects of Propylthiouracil and Methimazole as Graves' Disease Treatment on Vascular Atherosclerosis Markers: A Randomized Clinical Trial

BACKGROUND

Hyperthyroidism is related to vascular atherosclerosis. Propylthiouracil (PTU) and methimazole, other than their antithyroid effects, may have different mechanisms in preventing atherogenesis in Graves' disease.

OBJECTIVE

This study aimed to investigate the effect of antithyroid drugs on markers of vascular atherosclerosis in Graves' hyperthyroidism.

METHODS

This study was a single-blind, randomized clinical trial conducted on 36 patients with Graves' disease in Cipto Mangunkusumo General Hospital, Jakarta, Indonesia, from June 2019 until July 2020. Graves' disease was diagnosed from clinical manifestation of hyperthyroidism with diffuse goiter and then confirmed by thyroid stimulation hormone (TSH), free T4 (fT4), and TSH-receptor antibody (TRAb) measurements. Participants were randomly assigned to either a PTU or a methimazole treatment group and followed up for 3 months. Markers of vascular atherosclerosis were represented by adhesion molecules [intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin], carotid artery stiffness [pulse wave velocity (PWV)], and thickness [carotid intima media thickness (cIMT)].

RESULTS

By the end of the study, 24 participants reached euthyroid condition (13 from the PTU group and 11 from the methimazole group). After 3 months of follow-up, in the PTU group, we noticed an improvement of ICAM-1 [pretreatment: 204.1 (61.3) vs. posttreatment: 141.6 (58.4) ng/ml; p = 0.001], VCAM-1 [837 (707-977) vs. 510 (402-630) ng/ml; p < 0.001] and E-selectin [32.1 (24.1-42.7) vs. 28.2 (21.6-36.8) ng/ml; p = 0.045] in the PTU group. In the methimazole group, only VCAM-1 improvement [725 (565-904) vs. 472 (367-590); p = 0.001] was observed. Meanwhile, we found no significant changes in PWV or cIMT in either group.

CONCLUSION

Antithyroid treatment in Graves' disease leads to improvement in adhesion molecules, with a lesser effect on methimazole, whereas there were no significant changes in PWV or cIMT. PTU may have a better mechanism compared with methimazole in terms of improving adhesion molecules.

Cardiovascular risk factors in children and adolescents with subclinical hypothyroidism: A protocol for meta-analysis and systematic review

INTRODUCTION

Subclinical hypothyroidism (SH) is serum thyrotropin (TSH) slightly increased, while serum free thyroxine (FT4) levels are normal, and patients may have no abnormal symptoms, or only slight hypothyroidism, there are many studies proving that SH does increase cardiovascular risk in adults. However, there are few studies in children and adolescents. In order to explore whether children with subclinical hypothyroidism have a higher cardiovascular risk, we designed this meta-analysis.

METHODS

The protocol of this systematic review and meta-analysis was registered on the NPLASY (No. 202040182). The following electronic databases will be searched from the inception through the present to find studies that live up to our standard: PubMed, EMBASE, Web of Science, Cochrane Library, CNKI, Wanfang, and VIP. And we will include case-control studies, cohort studies, and cross-sectional studies. For including study, we will use the Newcastle-Ottawa Scale to evaluate their quality. Then 2 researchers will independently extract the required information. I statistics and subgroups will be used to analyze heterogeneity. We conduct a sensitivity analysis by excluding literature successively. When the system review contains >10 articles, Egger test will be conducted to evaluate publication bias.

RESULTS

From this study, we will assess the cardiovascular risk of children and adolescents with SH from multiple perspectives.

CONCLUSION

The conclusion of this paper will provide evidence for cardiovascular risk of SH children and provide basis for prevention and treatment of SH.

ETHICS AND DISSEMINATION

This meta-analysis does not collect personal primary data, so there is no need for formal moral recognition. The results of the system review will be presented to national and international conferences for publication.

α-Lipoic Acid Ameliorates The Changes in Prooxidant-Antioxidant Balance in Liver and Brain Tissues of Propylthiouracil-Induced Hypothyroid Rats

Objective

There are controversial data about the prooxidant-antioxidant balance in hypothyroidism. We aimed to investigate the effect of α-lipoic acid (ALA) on oxidative stress parameters in the liver and brain of propylthiouracil (PTU)-induced hypothyroid rats.

Materials and Methods

In this experimental study, PTU (500 mg/L) was given to rats in drinking water for 10 weeks. ALA (0.2% in diet) alone and together with thyroxine (T4, 20 µg/kg body weight, s.c) were given to hypothyroid rats in the last 5 weeks of the experimental period. The levels of reactive oxygen species, malondialdehyde, protein carbonyl, ferric reducing antioxidant power (FRAP) and glutathione (GSH) levels, superoxide dismutase, and GSH peroxidase activities were determined in the liver and brain of rats. Histopathological examinations were also performed.

Results

Prooxidant parameters were increased in the brain but not liver in hypothyroid rats. ALA treatment alone lowered enhanced brain oxidative stress in hypothyroid rats. Also, ALA was found to ameliorate the changes as a result of oxidative stress arising from T4 replacement therapy.

Conclusion

Our results indicate that ALA alone and together with T4 may be useful in reducing oxidative stress in thyroid dysfunctions.

Regulation of nitric oxide production in hypothyroidism

Hypothyroidism is a common endocrine disorder that predominantly occurs in females. It is associated with an increased risk of cardiovascular diseases (CVD), but the molecular mechanism is not known. Disturbance in lipid metabolism, the regulation of oxidative stress, and inflammation characterize the progression of subclinical hypothyroidism. The initiation and progression of endothelial dysfunction also exhibit these changes, which is the initial step in developing CVD. Animal and human studies highlight the critical role of nitric oxide (NO) as a reliable biomarker for cardiovascular risk in subclinical and clinical hypothyroidism. In this review, we summarize the recent literature findings associated with NO production by the thyroid hormones in both physiological and pathophysiological conditions. We also discuss the levothyroxine treatment effect on serum NO levels in hypothyroid patients.

The effect of eplerenone on the renin-angiotensin-aldosterone system of rats with thyroid dysfunction

OBJECTIVES

This study was conducted to evaluate the effect of eplerenone on the RAAS and kidney function in rats with thyroid hormone disorders.

METHODS

This study involved 30 male Wistar albino rats, divided into three groups. The first group (N = 6) served as a control. The second group involved 12 rats with experimentally induced hypothyroidism through receiving propylthiouracil (0.05% w/v) in drinking water for one month, which was divided into two subgroups of six rats each. The first subgroup served as a positive hypothyroid control, and the second subgroup received oral daily dose of eplerenone (100 mg/kg) for 14 days. The third group included 12 rats with induced hyperthyroidism with L-thyroxin (0.0012% w/v) in drinking water, and rats in this group were also divided into two subgroups. The first subgroup served as a positive hyperthyroid control, and the second subgroup received oral eplerenone 100 mg/kg.

RESULTS

Eplerenone indicated a significant increase in renin and angiotensin I from 184.09 pg/ml and 178.66 pg/ml to 603.31 pg/ml and 250.88 pg/ml, respectively, meanwhile, aldosterone indicated no significant changes after inducing hypothyroidism and eplerenone administration. The induction of hyperthyroidism led to a significant increase in angiotensin I from 248.84 pg/ml to 292.22 pg/ml. Oral administration of eplerenone for 14 days caused a significant increase aldosterone from 364.23 pg/ml to 497.02 pg/ml.

CONCLUSION

Eplerenone significantly increased the serum renin and angiotensin I in hypothyroid and aldosterone and angiotensin I in hyperthyroid rats. Aldosterone in hypothyroid rats was not changed by eplerenone.

Global perspective on carotid intima-media thickness and plaque: should the current measurement guidelines be revisited?

Carotid intima-media thickness (cIMT) and carotid plaque (CP) currently act as risk predictors for CVD/Stroke risk assessment. Over 2000 articles have been published that cover either use cIMT/CP or alterations of cIMT/CP and additional image-based phenotypes to associate cIMT related markers with CVD/Stroke risk. These articles have shown variable results, which likely reflect a lack of standardization in the tools for measurement, risk stratification, and risk assessment. Guidelines for cIMT/CP measurement are influenced by major factors like the atherosclerosis disease itself, conventional risk factors, 10-year measurement tools, types of CVD/Stroke risk calculators, incomplete validation of measurement tools, and the fast pace of computer technology advancements. This review discusses the following major points: 1) the American Society of Echocardiography and Mannheim guidelines for cIMT/CP measurements; 2) forces that influence the guidelines; and 3) calculators for risk stratification and assessment under the influence of advanced intelligence methods. The review also presents the knowledge-based learning strategies such as machine and deep learning which may play a future role in CVD/stroke risk assessment. We conclude that both machine learning and non-machine learning strategies will flourish for current and 10-year CVD/Stroke risk prediction as long as they integrate image-based phenotypes with conventional risk factors.

Dysregulation of MicroRNA Regulatory Network in Lower Extremities Arterial Disease

Atherosclerosis and its comorbidities are the major contributors to the global burden of death worldwide. Lower extremities arterial disease (LEAD) is a common manifestation of atherosclerotic disease of arteries of lower extremities. MicroRNAs belong to epigenetic factors that regulate gene expression and have not yet been extensively studied in LEAD. We aimed to indicate the most promising microRNA and gene expression signatures of LEAD, to identify interactions between microRNA and genes and to describe potential effect of modulated gene expression. High-throughput sequencing was employed to examine microRNAome and transcriptome of peripheral blood mononuclear cells of patients with LEAD, in relation to controls. Statistical significance of microRNAs and genes analysis results was evaluated using DESeq2 and uninformative variable elimination by partial least squares methods. Altered expression of 26 microRNAs (hsa-let-7f-1-3p, hsa-miR-34a-5p, -122-5p, -3591-3p, -34a-3p, -1261, -21-5p, -15a-5p, -548d-5p, -34b-5p, -424-3p, -548aa, -548t-3p, -4423-3p, -196a-5p, -330-3p, -766-3p, -30e-3p, -125b-5p, -1301-3p, -3184-5p, -423-3p, -339-3p, -138-5p, -99a-3p, and -6087) and 14 genes (AK5, CD248, CDS2, FAM129A, FBLN2, GGT1, NOG, NRCAM, PDE7A, RP11-545E17.3, SLC12A2, SLC16A10, SLC4A10, and ZSCAN18) were the most significantly differentially expressed in LEAD group compared to controls. Discriminative value of revealed microRNAs and genes were confirmed by receiver operating characteristic analysis. Dysregulations of 26 microRNAs and 14 genes were used to propose novel biomarkers of LEAD. Regulatory interactions between biomarker microRNAs and genes were studied in silico using R multiMiR package. Functional analysis of genes modulated by proposed biomarker microRNAs was performed using DAVID 6.8 tools and revealed terms closely related to atherosclerosis and, interestingly, the processes involving nervous system. The study provides new insight into microRNA-dependent regulatory mechanisms involved in pathology of LEAD. Proposed microRNA and gene biomarkers of LEAD may provide new diagnostic and therapeutic opportunities.

Circulating Angptl3 and Angptl8 Are Increased in Patients with Hypothyroidism

Purpose

Angiopoietin-like proteins (Angptls) play critical roles in biological processes, primarily in lipid metabolism. The functional state of the thyroid has a profound influence on metabolism in the human body. Therefore, the aim of this study was to investigate possible changes in serum Angptl3, 4, and 8 levels in hypothyroid patients.

Methods

The study included 29 patients with clinical hypothyroidism, 30 patients with subclinical hypothyroidism, and 29 healthy subjects. Baseline clinical indices, including serum thyroid function tests, were recorded and serum Angptl3, 4, and 8 levels were measured across the three groups.

Results

Serum Angptl3 and 8 levels were significantly higher in the hypothyroid groups compared to the control group (p < 0.05). There were no differences in Angptl4 levels among the three groups (p > 0.05). Positive correlations were identified between Angptl3 and high-density lipoprotein cholesterol (r = 0.431, p < 0.001), and there was a negative correlation between Angptl3 and total tri-iodothyronine (TT3) (r = -0.220, p = 0.047) and free tri-iodothyronine (r = - 0.279, p = 0.013) levels. Angptl8 was positively correlated with triglyceride (r = 0.267, p = 0.012) and cholesterol levels (r= 0.235, p = 0.028) but was negatively correlated with tri-iodothyronine (r = -0.24, p = 0.031). Furthermore, we used receiver operating characteristic curve analysis to evaluate the diagnostic performance of Angptl3 and 8 in discriminating thyroid dysfunction. The area under curve for detecting thyroid dysfunction based on Angptl3 and Angptl8 was 0.763.

Conclusions

Our data show that serum Angptl3 and 8 levels are increased in clinical and subclinical hypothyroid patients and that Angptl3 and 8 may serve as possible biomarkers of hypothyroid disease.

Serum retinol-binding protein 4 is associated with the presence and severity of coronary artery disease in patients with subclinical hypothyroidism

Subclinical hypothyroidism (SCH) plays a crucial role in the development and progression of coronary heart disease (CAD). Retinol-binding protein 4 (RBP4) is an adipokine correlated with cardiovascular diseases. Recent studies found that RBP4 levels are increased in patients with SCH. However, the relationship of RBP4 with CAD in SCH patients remains unclear. A total of 199 SCH patients (148 with CAD and 51 without CAD) and 102 healthy controls were enrolled in this study. Serum RBP4 was increased in SCH patients than controls. Moreover, serum RBP4 was higher in SCH patients with CAD. Although there was no significant difference of metabolic parameters between SCH patients with and without CAD, serum RBP4 was positively correlated with body mass index, total cholesterol, and low-density lipoprotein cholesterol, as well as thyroid stimulating hormone. Multivariable logistic regression analyses revealed elevated RBP4 was correlated with increased risk for CAD in SCH patients. Serum RBP4 levels were also increased as the number of stenosed vessels increased. Furthermore, increased RBP4 was positively correlated with the severity of CAD quantified by the Gensini score. Our findings demonstrate that serum RBP4 is associated with the presence and severity of CAD in patients with SCH.

Haemostatic effects of levothyroxine and selenomethionine in euthyroid patients with Hashimoto’s thyroiditis

The aim of this prospective study was to investigate for the first time whether levothyroxine and selenomethionine, administered alone or in combination, affect coagulation and fibrinolysis in Hashimoto’s thyroiditis patients with normal thyroid function tests. A group of 155 ambulatory women with recently diagnosed and previously untreated Hashimoto’s thyroiditis, of whom 149 completed the study, were randomly assigned in a double-blind fashion to six months of treatment with levothyroxine, selenomethionine, levothyroxine plus selenomethionine, or placebo. The control group included 39 matched healthy women. The prothrombin time ratio, the activated partial thromboplastin time, and plasma levels/activities of fibrinogen, factor VII, von Willebrand factor, factor X and plasminogen activator inhibitor-1 (PAI-1) were assessed at baseline and after three and six months of treatment. Compared with the healthy subjects, Hashimoto’s thyroiditis patients exhibited higher plasma levels/activities of all of the parameters studied, as well as were characterised by the abnormal prothrombin time ratio and activated partial thromboplastin time. All these haemostatic disturbances were reduced or normalised by levothyroxine + selenomethionine treatment, while the effect of levothyroxine or selenomethionine was limited to fibrinogen and PAI-1, respectively. Our results demonstrate that euthyroid women with Hashimoto’s thyroiditis are characterised by abnormal coagulation and fibrinolysis. Levothyroxine and selenomethionine, especially if administered together, produce a beneficial effect on haemostasis in euthyroid patients with this disorder.

Note: This study was in part a sub-study of another trial (ACTRN 12611000238976), which assessed the effect of levothyroxine and selenomethionine, administered alone or in combination, on monocyte and lymphocyte cytokine release in Hashimoto“s thyroiditis patients. Trial no.: ACTRN12612000271808.

Hemostasis in Hypothyroidism and Autoimmune Thyroid Disorders

CONTEXT

There are contradictory results on the effect of hypothyroidism on the changes in hemostasis. Inadequate population-based studies limited their clinical implications, mainly on the risk of venous thromboembolism (VTE). This paper reviews the studies on laboratory and population-based findings regarding hemostatic changes and risk of VTE in hypothyroidism and autoimmune thyroid disorders.

EVIDENCE ACQUISITION

A comprehensive literature search was conducted employing MEDLINE database. The following words were used for the search: Hypothyroidism; thyroiditis, autoimmune; blood coagulation factors; blood coagulation tests; hemostasis, blood coagulation disorders; thyroid hormones; myxedema; venous thromboembolism; fibrinolysis, receptors thyroid hormone. The papers that were related to hypothyroidism and autoimmune thyroid disorder and hemostasis are used in this review.

RESULTS

Overt hypothyroidism is more associated with a hypocoagulable state. Decreased platelet count, aggregation and agglutination, von Willebrand factor antigen and activity, several coagulation factors such as factor VIII, IX, XI, VII, and plasminogen activator-1 are detected in overt hypothyrodism. Increased fibrinogen has been detected in subclinical hypothyroidism and autoimmune thyroid disease rendering a tendency towards a hypercoagulability state. Increased factor VII and its activity, and plasminogen activator inhibitor-1 are among several findings contributing to a prothrombotic state in subclinical hypothyroidism.

CONCLUSIONS

Overt hypothyroidism is associated with a hypocoagulable state and subclinical hypothyroidism and autoimmune thyroid disorders may induce a prothrombotic state. However, there are contradictory findings for the abovementioned thyroid disorders. Prospective studies on the risk of VTE in various levels of hypofunctioning of the thyroid and autoimmune thyroid disorders are warranted.

Levels of endothelial cell-specific molecule-1 (ESM-1) in overt hypothyroidisim

PURPOSE

Endothelial cell-specific molecule-1, endocan, is a proteoglycan that is expressed by the vascular endothelium. Endocan can be a biomarker of endothelial dysfunction caused by endothelial cell-dependent disorders. Endothelial dysfunction is an early step of atherosclerosis and is developed in hypothyroid patients, which indicates an association between hypothyroidism and atherosclerosis. Therefore, we aimed to investigate whether circulating endocan levels are associated with endothelial dysfunction in overt hypothyroid patients.

MATERIALS AND METHODS

Forty patients with hypothyroidism diagnosed in the last 5 years and 30 healthy subjects were recruited.

RESULTS

The mean endocan value in all patients was 0.63 ± 0.26 pg/ml, which was higher than that in controls (0.36 ± 0.10 pg/ml, p < 0.05). When we subgrouped the patients as hypothyroid and euthyroid, all groups demonstrated significantly different endocan levels, and hypothyroid patients had the highest endocan levels. A correlation analysis demonstrated that endocan levels were positively correlated with body mass index (BMI), thyroid-stimulating hormone (TSH), anti-thyroid peroxidase, and anti-thyroglobulin and negatively correlated with free thyroid hormone 4 (FT4) and vitamin D levels. In addition, in the patient group, endocan levels were correlated with FT4 levels independently in a covariance analysis.

CONCLUSIONS

The circulating endocan level increased in hypothyroid patients, suggesting that endocan levels may be an early biomarker of the development of endothelial dysfunction in patients with hypothyroidism. They may also prove useful in the prediction of cardiovascular diseases after further studies using cardiovascular disease biomarkers. In addition, targeting endocan levels to decrease cardiovascular risk may be a new treatment strategy in these patients.

Impact of free thyroxine levels and other clinical factors on bare metal stent restenosis

Objective

Thyroid hormones have both direct and indirect effects on thermogenesis such as modulating vascular smooth muscle cell proliferation. However, the influence of more subtle changes in thyroid hormones on coronary atherosclerosis remains a matter of speculation. Smooth muscle cells play a crucial role in the pathogenesis of in-stent restenosis (ISR). However, the relationship between free thyroxine (fT4) and ISR has not been studied. In the present study, we aimed to assess the role of preprocedural serum fT4 level on the development of ISR in patients undergoing coronary bare metal stent (BMS) implantation.

Materials and methods

We enrolled and analyzed clinical, biochemical, and angiographic data from 705 consecutive patients without a history of primary thyroid disease [mean age 60.3 ± 9.3 years, 505 (72%) male]; all patients had undergone BMS implantation and further control coronary angiography owing to stable or unstable angina pectoris. Patients were divided into 3 tertiles based on preprocedural serum fT4 levels.

Results

ISR was observed in 53 (23%) patients in the lowest tertile, 82 (35%) patients in the second tertile, and 107 (46%) patients in the highest fT4 tertile (p < 0.001). Using multiple logistic regression analysis, five characteristics emerged as independent predictors of ISR: diabetes mellitus, smoking, HDL-cholesterol, stent length, and preprocedural serum fT4 level. In receiver operating characteristics curve analysis, fT4 level > 1.23 mg/dL had 70% sensitivity and 73% specificity (AUC: 0.75, p < 0.001) in predicting ISR.

Conclusion

Higher preprocedural serum fT4 is a powerful and independent predictor of BMS restenosis in patients with stable and unstable angina pectoris.

Paleopathology of cardiovascular diseases in South American mummies

BACKGROUND

Cardiovascular disease has emerged as the world's leading cause of death in the last century. An epidemiological focus of this disease that extends not only beyond the developed world but also far back into antiquity asks new questions about associated risk factors. Ancient mummies found in the Atacama desert are well preserved and show signs of cardiovascular disease as early as 1000B.C. in Peru and Chile.

METHOD AND RESULTS

Gross and histopathological examination of specimens shows atherosclerosis, cardiomegaly, endocarditis, and myocardial fibrosis.

CONCLUSION

In comparison to other ancient populations, less atherosclerosis has been noted in South American mummies. The chewing of coca leaves, a habitual cultural practice unique to the region, supports evidence of reduced cardiovascular risk among ancient people living in South America.

Homocysteine diminishes apolipoprotein A-I function and expression in patients with hypothyroidism: a cross-sectional study

Background

Hypothyroidism (HO) can significantly impair lipid metabolism and increase cardiovascular disease risk. Hyperhomocysteinemia (HHcy) is an independent risk factor for cardiovascular disease. Our previous study demonstrated that HHcy significantly induced insulin resistance and impaired coronary artery endothelial function in patients with either hypertension or HO. In the present study, we studied whether plasma levels of high-density lipoprotein-cholesterol (HDL-C) and apolipoprotein A-I (Apo A-I) were altered in patients with HO, and if so, whether this change was mediated by HHcy.

Methods

A total of 258 subjects were enrolled and divided into the following three groups: control group (n = 94), HO group (n = 73), and subclinical hypothyroidism (SHO) group (n = 91). Additionally, all groups were subdivided based on the subjects’ Hcy levels into HHcy (plasma Hcy level over 15 μmol/l) and normal Hcy subgroups. The plasma levels of lipid indexes were measured. Statistical analyses were performed to evaluate the correlations between groups.

Results

The plasma Hcy levels were significantly higher in the HO group than in the SHO or control groups (all p < 0.05). Moreover, levels of Apo A-I and HDL-C were markedly reduced in the HHcy subgroup compared with the normal Hcy subgroup for patients with either HO (Apo A-I: p < 0.05; HDL-C: p < 0.01) or SHO (Apo A-I: p < 0.05; HDL-C: p < 0.01). In addition, the plasma Hcy levels were negatively correlated with levels of Apo A-I in all three groups (HO group: r = − 0.320, SHO group: r = − 0.337 and control group: r = − 0.317; all p < 0.01).

Conclusions

Hcy levels were significantly increased in patients with HO or SHO. These increased Hcy levels may impair cardiovascular function via the inhibition of Apo A-1 expression and impairment of its antioxidant capacity. Our findings provide new insights into the pathogenesis of hypothyroidism-induced metabolic disorders.

Subclinical hypothyroidism causing hypertension in pregnancy

This is a case of a 25-year-old primigravida who was referred to the hypertension specialist for elevated blood pressures. The patient had an elevated thyroid-stimulating hormone with normal free thyroxine (T4) levels and was positive for thyroid peroxidase antibodies resulting in a diagnosis of subclinical hypothyroidism. The patient was successfully treated with levothyroxine which normalized the blood pressure without the need for antihypertensive treatment. This case illustrates a cause of secondary hypertension that is not always considered in the differential diagnosis of a patient with hypertension in pregnancy.

Potential harmful correlation between homocysteine and low-density lipoprotein cholesterol in patients with hypothyroidism

OBJECTIVE

Hypothyroidism (HO) can induce metabolic dysfunctions related to insulin resistance and dyslipidemia. Our previous studies showed that homocysteine (Hcy) impaired the coronary endothelial function and that Hcy can promote chemokine expression and insulin resistance (IR) by inducing endoplasmic reticulum stress in human adipose tissue and hypothyroid patients. The aim of this study was to investigate the potential harmful correlation between plasma Hcy and low-density lipoprotein cholesterol (LDL-C) in patients with HO.

METHODS

A total of 286 subjects were enrolled. All subjects were divided into the following 3 groups: HO group, subclinical hypothyroidism (SHO) group, and control group. Statistical analyses were carried out to evaluate the correlation between the plasma levels of Hcy and LDL-C in HO patients. The changes in the plasma Hcy levels and other metabolic parameters were measured before and after levothyroxine (L-T4) treatment. The relationship between the changes in the plasma Hcy level and the LDL-C level was also evaluated after L-T4 treatment.

RESULTS

In the patients with HO, both the plasma Hcy and LDL-C levels were significantly higher than those of the controls. The plasma levels of Hcy were positively correlated with the LDL-C level in the HO group. L-T4 treatment resulted in a significant decrease in the BMI, total cholesterol (TC), LDL-C, triglycerides (TG), apolipoprotein B (ApoB), and Hcy levels. Moreover, the decrease in Hcy (ΔHcy) was positively correlated with decreased LDL-C (ΔLDL-C) levels after L-T4 treatment in HO patients.

CONCLUSION

Our results suggest that the increased Hcy level was positively correlated with the LDL-C in the HO group. A potential harmful interaction may exist between Hcy and LDL-C under the HO condition. In addition to reducing the plasma levels of Hcy, L-T4 treatment exerts beneficial effects on patients with HO by improving dyslipidemia, including a decrease in the LDL-C level.

Low free triiodothyronine levels are related to symptomatic intracranial hemorrhage and poor functional outcomes after intravenous thrombolysis in acute ischemic stroke patients

BACKGROUND AND OBJECTIVE

Low free triiodothyronine (fT3) levels have been associated with increased mortality and poor functional outcomes in patients with stroke. However, the research of relationship between fT3 levels and acute ischemic stroke (AIS) patients with intravenous thrombolysis (IVT) is scarce. We aimed to investigate the association of fT3 levels with symptomatic intracranial hemorrhage (sICH) and functional outcomes at discharge in AIS patients with IVT.

METHODS

Patients with AIS admitted to West China hospital, Sichuan University, who had underwent IVT treatment, were consecutively and retrospectively included. Demographic and clinical information were collected and analyzed according to the levels of fT3. We used logistic regression analysis to estimate the multivariable adjusted association of fT3 levels and post-IVT sICH, and functional outcomes at discharge.

RESULTS

Among the 46 patients (26 males; mean age, 63.6 years) in the final analysis, 17 patients (37.0%) had fT3 levels lower than the reference range. After adjustment for age, gender, and statistically important variables (NIHSS on admission, urea levels and creatinine levels), low fT3 levels were significantly associated with post-IVT sICH (p = 0.01, OR = 0.27, 95% CI 0.10-0.77) and poor functional outcomes at discharge (p = 0.04 OR = 2.58, 95% CI 1.05-6.35).

CONCLUSION

We found that lower free T3 levels are independently related to post-IVT sICH and poor functional outcomes at discharge in AIS patients with IVT, which should be verified and extended in large cohorts in the future.

Clinical outcomes of patients with hypothyroidism undergoing percutaneous coronary intervention

AIMS

The aim of this study was to investigate the association between hypothyroidism and major adverse cardiovascular and cerebral events (MACCE) in patients undergoing percutaneous coronary intervention (PCI).

METHODS AND RESULTS

Two thousand four hundred and thirty patients who underwent PCI were included. Subjects were divided into two groups: hypothyroidism (n = 686) defined either as a history of hypothyroidism or thyroid-stimulating hormone (TSH) ≥5.0 mU/mL, and euthyroidism (n = 1744) defined as no history of hypothyroidism and/or 0.3 mU/mL ≤ TSH < 5.0 mU/mL. Patients with hypothyroidism were further categorized as untreated (n = 193), or those taking thyroid replacement therapy (TRT) with adequate replacement (0.3 mU/mL ≤ TSH < 5.0 mU/mL, n = 175) or inadequate replacement (TSH ≥ 5.0 mU/mL, n = 318). Adjusted hazard ratios (HRs) were calculated using Cox proportional hazards models. Median follow-up was 3.0 years (interquartile range, 0.5-7.0). After adjustment for covariates, the risk of MACCE and its constituent parts was higher in patients with hypothyroidism compared with those with euthyroidism (MACCE: HR: 1.28, P = 0.0001; myocardial infarction (MI): HR: 1.25, P = 0.037; heart failure: HR: 1.46, P = 0.004; revascularization: HR: 1.26, P = 0.0008; stroke: HR: 1.62, P = 0.04). Compared with untreated patients or those with inadequate replacement, adequately treated hypothyroid patients had a lower risk of MACCE (HR: 0.69, P = 0.005; HR: 0.78, P = 0.045), cardiac death (HR: 0.43, P = 0.008), MI (HR: 0.50, P = 0.0004; HR: 0.60, P = 0.02), and heart failure (HR: 0.50, P = 0.02; HR: 0.52, P = 0.017).

CONCLUSION

Hypothyroidism is associated with a higher incidence of MACCE compared with euthyroidism in patients undergoing PCI. Maintaining adequate control on TRT is beneficial in preventing MACCE.

Cardiovascular comorbidity in rheumatic diseases

Patients with rheumatoid arthritis (RA) and other inflammatory joint diseases (IJDs) have an increased risk of premature death compared with the general population, mainly because of the risk of cardiovascular disease, which is similar in patients with RA and in those with diabetes mellitus. Pathogenic mechanisms and clinical expression of cardiovascular comorbidities vary greatly between different rheumatic diseases, but atherosclerosis seems to be associated with all IJDs. Traditional risk factors such as age, gender, dyslipidaemia, hypertension, smoking, obesity and diabetes mellitus, together with inflammation, are the main contributors to the increased cardiovascular risk in patients with IJDs. Although cardiovascular risk assessment should be part of routine care in such patients, no disease-specific models are currently available for this purpose. The main pillars of cardiovascular risk reduction are pharmacological and nonpharmacological management of cardiovascular risk factors, as well as tight control of disease activity.

Effect of Excessive Potassium Iodide on Rat Aorta Endothelial Cells

The aim of the current study was to investigate the effect of excess iodine on rat aorta endothelial cells and the potential underlying mechanisms. Rat aorta endothelial cells were cultured with iodide ion (3506, 4076, 4647, 5218, 5789, 6360, 6931, and 7512 mg/L) for 48 h. Morphological changes of cells were observed with microscope after Wright-Giemsa staining and acridine orange staining. Cell proliferation was determined with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and cell apoptosis was assessed with flow cytometry. The activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), endothelial nitric oxide synthase (eNOS), induced nitric oxide synthase (iNOS), and concentrations of malondialdehyde (MDA), glutathione (GSH), and protein carbonyl in culture medium were determined with colorimetric method. The expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) was detected by enzyme linked immunosorbent assay. The results showed that excess iodine induced abnormal morphologic changes of cells, inhibited cell proliferation, and increased apoptosis rate. Iodine also reduced the activity of SOD, GSH-Px, and concentrations of GSH and increased the concentrations of MDA and protein carbonyl in a dose-dependent manner. Moreover, excess iodine decreased the activity of eNOS and increased the activity of iNOS and the expression of ICAM-1 and VCAM-1 in culture medium. Our results suggested that excess iodine exposure increased oxidative stress, caused damage of vascular endothelial cells, and altered the expression of adhesion factors and the activity of NOS. These changes may explain the mechanisms underlying excess iodine-induced vascular injury.

Novel Clinical Evidence of an Association between Homocysteine and Insulin Resistance in Patients with Hypothyroidism or Subclinical Hypothyroidism

Objective

Hypothyroidism (HO) can induce significant metabolic dysfunction and increase cardiovascular disease risk. In the present study, we investigated the relationship between homocysteine (Hcy) and insulin resistance (IR) in patients with HO or subclinical hypothyroidism (SHO).

Methods

A total of 270 subjects were enrolled. All subjects were divided into the following three groups: HO, SHO and control. Plasma levels of Hcy were measured, and each patient’s homeostatic index of insulin resistance (HOMA-IR) was calculated. Statistical analyses were carried out to evaluate the correlations among groups and to determine the predictors of IR in patients with HO or SHO.

Results

The HOMA-IR value was significantly higher in the HO group than in the SHO and control groups. Plasma levels of Hcy were markedly increased in the HO group compared with those of the SHO group and controls. In addition, plasma levels of Hcy were positively correlated with the HOMA-IR values in both the HO and SHO groups. Multiple linear regression models showed that plasma levels of Hcy and free thyroxine (FT4) were the only predictors of HOMA-IR in patients with HO or SHO.

Conclusions

Plasma levels of Hcy and HOMA-IR were increased in patients with HO or SHO. Our results suggest that HO and SHO may increase the risk for atherogenesis and cardiovascular disease by increased IR. The increased IR induced by hyperhomocysteinemia in patients with HO or SHO may partially explain this adverse effect.

Association between lipids profile and thyroid parameters in euthyroid diabetic subjects: a cross-sectional study

BACKGROUND

The concept is now emerging that higher thyroid-stimulating hormone (TSH) and lower thyroid hormone levels within the euthyroid range may adversely affect atherosclerosis. The aim of this study was to investigate the potential association between thyroid parameters and lipids profile in a cohort of euthyroid diabetic subjects.

METHODS

Four hundred and sixty-two euthyroid type 2 diabetes subjects (302 males and 160 females) were consecutively recruited. Clinical and anthropometric data was collected from all participants. Whole blood samples were drawn in the morning after an overnight fasting for the measurement of serum TSH, free thyroxine (FT4), free triiothyronine (FT3), anti-thyroid peroxidase antibody (TPO-Ab) levels, as well as lipid concentrations and glucose.

RESULTS

TSH was higher in females than males. Stratified by TSH, high-density lipoprotein cholesterol (HDL-c) level increased in subjects with TSH ≥2.5uIU/mL (P = 0.004). And TSH was associated with HDL-c in a Pearson correlation test, however, the association failed to attain significance in partial correlation analyses, adjusted for age, sex, duration of diabetes, fasting glucose and BMI. In females, total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-c) level was significant lower in subjects with TSH <2.5uIU/mL. TSH was significantly associated with TC and LDL-c, even in a partial correlation analysis (P = 0.006 and 0.011, respectively). In a multiple linear regression analysis (stepwise), TSH was positive associated with TC (β = 0.202, P = 0.005) and LDL-c (β = 0.144, P = 0.010). In one hundred and six patients having TPO antibody assays, 6 (5.66%) were positive. The blood pressure and lipid levels were lower in TPO-Ab positive patients, however, the differences were not significantly.

CONCLUSIONS

In conclusion, we identified TSH was positively associated with serum TC and LDL-c in euthyroid diabetic women. Our analysis in the subgroup having TPO antibody assays demonstrating non-significantly lower TC levels among seropositive subjects was consistent with the above stated consideration for women as a whole. Further investigations are needed to understand the intimate mechanisms of lipid metabolism in type 2 diabetes with respect to thyroid function.

Echocardiographic assessment of left ventricular function in thyrotoxicosis and implications for the therapeutics of thyrotoxic cardiac disease

INTRODUCTION

Thyrotoxicosis is an endocrine disorder with prominent cardiovascular manifestations. Thyroid hormone acts through genomic and non-genomic mechanisms to regulate cardiac function. Echocardiography is a useful, non-invasive, easily accessible, and affordable tool for studying the structural and physiological function of the heart.

AIM

We studied thyrotoxicosis patients in a Nigerian Teaching Hospital and employed trans-thoracic echocardiography to find out if there were abnormalities in the hearts of these patients.

METHODS

Fifty adult thyrotoxicosis patients diagnosed with clinical and thyroid function tests in the medical out-patient unit of the hospital were recruited and we performed transthoracic echocardiography with a Sonos 2000 HP machine.

RESULTS

We documented the presence of abnormalities in the following proportion of thyrotoxicosis patients: left ventricular enhanced systolic function in 30%, enhanced diastolic function in 34%, diastolic dysfunction in 34%, heart failure with preserved ejection fraction in10%, heart failure with reduced ejection fraction in 6%, and left ventricular hypertrophy in 34%.

CONCLUSION

Echocardiography was useful in the stratification of cardiac function abnormalities and is indispensable as a guide in the choice of therapeutic options in patients with thyrocardiac disease. The finding of left ventricular enhanced systolic and diastolic functions signify early echocardiographic detectable cardiac abnormalities in thyrotoxicosis, and the clinical management includes the use of anti-thyroid drugs and β-adrenoceptor blockade. Diastolic dysfunction in thyrotoxicosis patients asymptomatic for cardiac disease should be treated with anti-thyroid drugs, and β-adrenoceptor blockade. The judicious application of clinical therapeutics will guide the use of anti-thyroid drugs, diuretics, digoxin, angiotensin inhibitors, and β-adrenoceptor blockade in the successful management of thyrotoxicosis patients with heart failure and reduced, preserved, or increased ejection fraction: parameters which are derived from echocardiography.

Effects of levothyroxine replacement therapy on parameters of metabolic syndrome and atherosclerosis in hypothyroid patients: a prospective pilot study

The aim of this study was to investigate the effect of levothyroxine (LT4) replacement therapy during three months on some parameters of metabolic syndrome and atherosclerosis in patients with increased thyroid-stimulating hormone (TSH) level. This study included a group of 30 female patients with TSH level >4 mIU/L and 15 matched healthy controls. Intima media complex thickness (IMCT) and peak systolic flow velocity (PSFV) of superficial femoral artery were determined by Color Doppler scan. In hypothyroid subjects, BMI, SBP, DBP, and TSH were significantly increased versus controls and decreased after LT4 administration. FT4 was significantly lower in hypothyroid subjects compared with controls and significantly higher by treatment. TC, Tg, HDL-C, and LDL-C were similar to controls at baseline but TC and LDL-C were significantly decreased by LH4 treatment. IMCT was significantly increased versus controls at baseline and significantly reduced by treatment. PSFV was similar to controls at baseline and significantly decreased on treatment. In this study, we have demonstrated the effects of LT4 replacement therapy during three months of treatment on correction of risk factors of metabolic syndrome and atherosclerosis.

Spectral analysis of femoral artery blood flow waveforms of conscious domestic cats

The qualitative and quantitative aspects of femoral artery blood flow waveform spectra were evaluated in 15 male and 15 female Persian and mixed breed domestic cats (Felis catus), which were healthy and not sedated, using duplex Doppler ultrasonography (DDU). Spectral Doppler demonstrated a biphasic characteristic in 16 (53.34%) of the animals evaluated, and a triphasic characteristic in the 14 (46.66%) remaining animals. The systolic blood pressure and heart rate values were within the normal range for the species. The quantitative parameters evaluated, based on the spectral Doppler, were as follows: systolic velocity peak (SVP), recent diastolic velocity peak (RDVP), end diastolic velocity peak (EDVP), mean velocity (MV), integral velocity time (ITV), artery diameter (AD), femoral flow volume (FFV), pulsatility index (PI), resistive index (RI), systolic peak acceleration time (AT) and deceleration time (DT). The respective mean values were: 36.41 ± 7.33 cm/s, 4.69 ± 0.90 cm/s, 10.74 ± 2.74 cm/s, 23.06 ± 4.86 cm/s, 3.91 ± 1.05 cm, 0.17 ± 0.04 cm, 0.11 ± 0.08 cm(3), 3.85 ± 0.19, 1.40 ± 0.20, 39.84 ± 7.38 ms, and 114.0 ± 22.15 ms. No significant differences were found between males and females. The analyses carried out on the femoral artery flow spectrum obtained by DDU showed that it is easy to use and highly tolerated in non-sedated, healthy cats. It appears that DDU may be a useful diagnostic technique, but further studies are needed to evaluate how it compares with invasive telemetric methodology or high-definition oscillometric waveform analytic techniques.