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Cui Y, Zhang Y, Dai S, Wan S, Guan H, Wang D, Jin B, Xiao W, Liu F. The mechanism of 14-3-3η in thyroxine induced mitophagy in cardiomyocytes. Mol Cell Endocrinol 2024; 590:112271. [PMID: 38759835 DOI: 10.1016/j.mce.2024.112271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 04/24/2024] [Accepted: 05/14/2024] [Indexed: 05/19/2024]
Abstract
Hyperthyroidism is becoming increasingly important as an independent risk factor for cardiovascular disease, eventually resulting in cardiac hypertrophy and heart failure. The 14-3-3 protein family subtypes regulate many cellular processes in eukaryotes by interacting with a diverse array of client proteins. Considering that the 14-3-3η protein protects cardiomyocytes by affecting mitochondrial function, exploring the biological influence and molecular mechanisms by which 14-3-3η alleviates the cardiac hypertrophy of hyperthyroidism is imperative. In vivo and in vitro, RT-PCR, Western blot, and Mitochondrial tracking assay were performed to understand the molecular mechanism of thyroxine-induced cardiomyocyte hypertrophy. HE staining, transmission electron microscopy, and immunofluorescence were used to observe intuitively changes of hearts and cardiomyocytes. The in vivo and in vitro results indicated that overexpression of the 14-3-3η ameliorated thyroxine-induced cardiomyocyte hypertrophy, whereas knockdown of the 14-3-3η protein aggravated thyroxine-induced cardiomyocyte hypertrophy. Additionally, overexpression of the 14-3-3η protein reduces thyroxine-induced mitochondrial damage and mitophagy in cardiomyocytes. Overexpression of 14-3-3η protein improves excessive mitophagy in the myocardium caused by thyroxine and thus prevents cardiac hypertrophy.
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Affiliation(s)
- Yalan Cui
- Department of Anatomy, College of Basic Medicine, Guilin Medical University, Guilin, Guangxi, 541004, China; Clinical Pathology Department, The Second People's Hospital of China Three Gorges University, Yichang, Hubei, 443600, China
| | - Yan Zhang
- Department of Anatomy, College of Basic Medicine, Guilin Medical University, Guilin, Guangxi, 541004, China
| | - Songsong Dai
- Department of Anatomy, College of Basic Medicine, Guilin Medical University, Guilin, Guangxi, 541004, China
| | - Sha Wan
- Department of Anatomy, College of Basic Medicine, Guilin Medical University, Guilin, Guangxi, 541004, China
| | - Heng Guan
- Department of Anatomy, College of Basic Medicine, Guilin Medical University, Guilin, Guangxi, 541004, China
| | - Decai Wang
- Department of Respiratory and Critical Care Medicine, Key Laboratory of Pulmonary Diseases of Health Ministry, Key Site of National Clinical Research Center for Respiratory Disease, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China
| | - Beifang Jin
- Department of Anatomy, College of Basic Medicine, Guilin Medical University, Guilin, Guangxi, 541004, China
| | - Wenping Xiao
- Department of Anatomy, College of Basic Medicine, Guilin Medical University, Guilin, Guangxi, 541004, China
| | - Fang Liu
- Department of Anatomy, College of Basic Medicine, Guilin Medical University, Guilin, Guangxi, 541004, China; Center of Diabetic Systems Medicine, Guangxi Key Laboratory of Excellence, Guilin Medical University, Guilin, Guangxi, 541004, China.
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Çelik S, Uç ZA, Candan Ö. Do Different TSH Suppression Levels Effect Heart Rate Variability and QT Dispersions in Patients with Differentiated Thyroid Cancer? Endocr Res 2024:1-8. [PMID: 39051971 DOI: 10.1080/07435800.2024.2383669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2024] [Revised: 07/11/2024] [Accepted: 07/18/2024] [Indexed: 07/27/2024]
Abstract
OBJECTIVE The aim of this study was to investigate changes in heart rate variability (HRV) and QT dispersion (QTd) in patients with differentiated thyroid cancer at different TSH suppression levels. METHODS The study included 125 DTC patients, who had been on TSH suppression treatment (TSHST) for at least 1 year. The patients were categorized into three groups: patients with TSH < 0.1 mIU/L (n:30), those with TSH 0.1 to 0.5 mIU/L (n:56), and those with TSH 0.5 to 2 mIU/L (n:39). The first two groups were classified as suppression groups, and the last as replacement (control) group. All patients underwent 12-lead electrocardiogram (ECG) recording and 24-hour rhythm holter echocardiography analysis. RESULTS The HRV results derived from a 24-hour rhythm holter did not exhibit any significant difference (p < 0.05). In dispersion evaluations, the QTd was significantly longer in the suppression groups (groups 1 and 2), than in the replacement group (group 3) (p < 0.001 and p:0.002, respectively). The same was found for corrected QT dispersion (QTcd) (p < 0.001 and p: 0.008, respectively). In multivariate linear regression analysis, TSH was found to affect QTd (β = -0.299; p = 0.002) and QTcd (β = -0.300; p = 0.002) values independently. CONCLUSION In this study, it was shown that in patients with DTC receiving TSHST, QT dispersion prolonged as the TSH suppression level increased. Especially in high-risk DTC patients, evaluation of QTd may be useful in terms of evaluating cardiovascular risk and regulating TSHST level.
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Affiliation(s)
- Semih Çelik
- Department of Internal Medicine, Faculty of Medicine, Usak University, Usak Training and Research Hospital, Usak, Turkey
| | - Ziynet Alphan Uç
- Department of Endocrinology and Metabolism, Faculty of Medicine, Usak University, Usak Training and Research Hospital, Usak, Turkey
| | - Özkan Candan
- Department of Cardiology, Faculty of Medicine, Usak University, Usak Training and Research Hospital, Usak, Turkey
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Pashaei M, Hesari M, Shackebaei D, Godini A. Cardioprotective effects of losartan and diminazene against the ischemia/reperfusion injury in hyperthyroidism rats. Can J Physiol Pharmacol 2024; 102:383-390. [PMID: 38377482 DOI: 10.1139/cjpp-2023-0122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Hyperthyroidism is a condition where the thyroid gland produces high levels of thyroid hormone. Heart diseases are one of the main complications of hyperthyroidism. Several studies have shown that losartan (LOS) and diminazene aceturate (DIZE) possess cardioprotection effects against cardiac hypertrophy, ischemic heart disease, and heart failure. The research aimed to investigate the cardioprotection of LOS, DIZE, and their combination in the case of levothyroxine (LT4)-induced cardiomyopathy in rats. Hyperthyroidism was induced by LT4 in drinking water (12 mg/L) for 28 days. LOS (10 mg/kg, orally) and/or DIZE (15 mg/kg, subcutaneously) were administrated in rats with hyperthyroidism for 28 days. Decreased serum creatine kinase myoglobin and lactate dehydrogenase levels and cardiac hypertrophy by DIZE and combination therapy in hyperthyroidism rats have been reported. Cardiac hemodynamic findings showed that DIZE and its combination with LOS decreased the LT4-mediated left ventricular developed pressure (LVDP), rate pressure product (RPP), and RPP recovery percentage. Elevated cardiac oxidative stress and inflammation were confirmed by decreasing cardiac superoxide dismutase (SOD) activity and increasing the total oxidative stress and tumor necrosis factor-alpha (TNF-α) levels. SOD activity and TNF-α level were reversed by LOS and DIZE administration, respectively. Generally, DIZE and combination therapy with LOS improved cardiac dysfunction caused by hyperthyroidism in rats, whereas LOS alone has not been able to effectively respond to this dysfunction.
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Affiliation(s)
- Mosayeb Pashaei
- Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
- Medical School, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Mahvash Hesari
- Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Dareuosh Shackebaei
- Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
- Cardiovascular Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Aliashraf Godini
- Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
- Department of Physiology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
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Lazar DR, Cainap S, Maniu D, Blag C, Bota M, Lazar FL, Achim A, Colceriu MC, Zdrenghea M. Anthracycline's Effects on Heart Rate Variability in Children with Acute Lymphoblastic Leukemia: Early Toxicity Signs-Pilot Study. J Clin Med 2023; 12:7052. [PMID: 38002666 PMCID: PMC10672281 DOI: 10.3390/jcm12227052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/08/2023] [Accepted: 11/10/2023] [Indexed: 11/26/2023] Open
Abstract
Anthracycline treatments are known to cause cardiotoxic long-term side effects in cancer survivors. Recently, a decrease in heart rate variability (HRV) has been identified in these patients, signaling autonomic dysfunction and altered cardiac fitness. This study aimed at evaluating changes in HRV in children treated with anthracyclines. A total of 35 pediatric patients with acute lymphoblastic leukemia were evaluated by means of a 24 h Holter ECG, at baseline and after reaching half the total cumulative dose of doxorubicin equivalent (120 mg/m2). Parameters of HRV were assessed, as well as any arrhythmic episodes, bradycardia and tachycardia percentages. The results showed a significant decrease in both time-domain and frequency-domain HRV parameters, following anthracycline treatment. The low-frequency (LF) to high-frequency (HF) parameters' ratio also displayed a significant difference (p = 0.035), suggestive of early cardiac autonomic dysfunction. Of note, none of the patients presented symptoms of heart disease or elevated troponins, and only two patients presented echocardiographic signs of diastolic dysfunction. The present study showed that cardiac autonomic nervous system regulation is compromised in children treated with anthracyclines even before reaching the total cumulative dose. Therefore, HRV parameters could be the first indicators of subclinical cardiac toxicity, making Holter ECG monitoring of the oncological patient a necessity.
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Affiliation(s)
- Diana R. Lazar
- Department No. 11, Oncology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
- Department of Pediatric Cardiology, Emergency Hospital for Children, 400394 Cluj-Napoca, Romania
| | - Simona Cainap
- Department of Pediatric Cardiology, Emergency Hospital for Children, 400394 Cluj-Napoca, Romania
- Department of Mother and Child, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Dana Maniu
- Biomolecular Physics Department, Faculty of Physics, “Babes-Bolyai” University, 400347 Cluj-Napoca, Romania
| | - Cristina Blag
- Department of Mother and Child, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
- Department of Pediatric Oncology and Hematology, Emergency Hospital for Children, 400394 Cluj-Napoca, Romania
| | - Madalina Bota
- Department of Mother and Child, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
- Department of Pediatric Oncology and Hematology, Emergency Hospital for Children, 400394 Cluj-Napoca, Romania
| | - Florin-Leontin Lazar
- Department No. 5, Internal Medicine, Medical Clinic Number 1, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Alexandru Achim
- Department of Cardiology, “Niculae Stancioiu” Heart Institute, Motilor 19-21, 400001 Cluj-Napoca, Romania
| | - Marius C. Colceriu
- Department of Functional Biosciences, Discipline of Physiology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Mihnea Zdrenghea
- Department No. 11, Oncology, “Iuliu Hatieganu” University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
- Department of Hematology, “Ion Chiricuta” Oncology Institute, 400015 Cluj-Napoca, Romania
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Dore R, Watson L, Hollidge S, Krause C, Sentis SC, Oelkrug R, Geißler C, Johann K, Pedaran M, Lyons G, Lopez-Alcantara N, Resch J, Sayk F, Iwen KA, Franke A, Boysen TJ, Dalley JW, Lorenz K, Moran C, Rennie KL, Arner A, Kirchner H, Chatterjee K, Mittag J. Resistance to thyroid hormone induced tachycardia in RTHα syndrome. Nat Commun 2023; 14:3312. [PMID: 37286550 DOI: 10.1038/s41467-023-38960-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 05/24/2023] [Indexed: 06/09/2023] Open
Abstract
Mutations in thyroid hormone receptor α1 (TRα1) cause Resistance to Thyroid Hormone α (RTHα), a disorder characterized by hypothyroidism in TRα1-expressing tissues including the heart. Surprisingly, we report that treatment of RTHα patients with thyroxine to overcome tissue hormone resistance does not elevate their heart rate. Cardiac telemetry in male, TRα1 mutant, mice indicates that such persistent bradycardia is caused by an intrinsic cardiac defect and not due to altered autonomic control. Transcriptomic analyses show preserved, thyroid hormone (T3)-dependent upregulation of pacemaker channels (Hcn2, Hcn4), but irreversibly reduced expression of several ion channel genes controlling heart rate. Exposure of TRα1 mutant male mice to higher maternal T3 concentrations in utero, restores altered expression and DNA methylation of ion channels, including Ryr2. Our findings indicate that target genes other than Hcn2 and Hcn4 mediate T3-induced tachycardia and suggest that treatment of RTHα patients with thyroxine in high dosage without concomitant tachycardia, is possible.
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Affiliation(s)
- Riccardo Dore
- Institute for Endocrinology and Diabetes, Center of Brain Behavior & Metabolism, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Laura Watson
- National Institute Health and Care Research Cambridge Clinical Research Facility, Addenbrooke's Hospital, Cambridge, UK
| | - Stefanie Hollidge
- MRC Epidemiology Unit and Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Christin Krause
- Institute for Human Genetics, Department of Epigenetics & Metabolism, Center of Brain Behavior & Metabolism, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Sarah Christine Sentis
- Institute for Endocrinology and Diabetes, Center of Brain Behavior & Metabolism, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Rebecca Oelkrug
- Institute for Endocrinology and Diabetes, Center of Brain Behavior & Metabolism, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Cathleen Geißler
- Institute for Endocrinology and Diabetes, Center of Brain Behavior & Metabolism, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Kornelia Johann
- Institute for Endocrinology and Diabetes, Center of Brain Behavior & Metabolism, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Mehdi Pedaran
- Institute for Endocrinology and Diabetes, Center of Brain Behavior & Metabolism, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Greta Lyons
- Wellcome-MRC Institute of Metabolic Science, Metabolic Research Laboratories, University of Cambridge, Cambridge, UK
| | - Nuria Lopez-Alcantara
- Institute for Endocrinology and Diabetes, Center of Brain Behavior & Metabolism, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Julia Resch
- Institute for Endocrinology and Diabetes, Center of Brain Behavior & Metabolism, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Friedhelm Sayk
- Internal Medicine I, Universitätsklinikum Schleswig-Holstein, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Karl Alexander Iwen
- Institute for Endocrinology and Diabetes, Center of Brain Behavior & Metabolism, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
- Internal Medicine I, Universitätsklinikum Schleswig-Holstein, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Andre Franke
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Rosalind-Franklin-Straße 12, 24105, Kiel, Germany
| | - Teide Jens Boysen
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Rosalind-Franklin-Straße 12, 24105, Kiel, Germany
| | - Jeffrey W Dalley
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK
- Department of Psychiatry, University of Cambridge, Cambridge, CB2 2QQ, UK
| | - Kristina Lorenz
- Institute of Pharmacology and Toxicology, University of Würzburg, Versbacher Straße 9, 97078, Wuerzburg, Germany
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Bunsen-Kirchhoff-Str. 11, 44139, Dortmund, Germany
| | - Carla Moran
- Wellcome-MRC Institute of Metabolic Science, Metabolic Research Laboratories, University of Cambridge, Cambridge, UK
- Beacon Hospital and School of Medicine, University College Dublin, Dublin, Ireland
| | - Kirsten L Rennie
- MRC Epidemiology Unit and Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - Anders Arner
- Department of Clinical Sciences, Lund University, c/o Igelösa Life Science AB, Igelösa 373, 225 94, Lund, Sweden
| | - Henriette Kirchner
- Institute for Human Genetics, Department of Epigenetics & Metabolism, Center of Brain Behavior & Metabolism, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Krishna Chatterjee
- Wellcome-MRC Institute of Metabolic Science, Metabolic Research Laboratories, University of Cambridge, Cambridge, UK
| | - Jens Mittag
- Institute for Endocrinology and Diabetes, Center of Brain Behavior & Metabolism, University of Lübeck, Ratzeburger Allee 160, 23562, Lübeck, Germany.
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Byeon H, Moon Y, Lee S, Son GI, Lee E. Effect of the Marine Exercise Retreat Program on Thyroid-Related Hormones in Middle-Aged Euthyroid Women. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:1542. [PMID: 36674297 PMCID: PMC9863542 DOI: 10.3390/ijerph20021542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 01/11/2023] [Accepted: 01/12/2023] [Indexed: 06/17/2023]
Abstract
This study aimed to investigate the effects of a marine exercise retreat program on thyroid-related hormone levels. A total of 62 middle-aged euthyroid women participated in a 6-day marine exercise retreat program. Using thyroid-stimulating hormone (TSH) and free thyroxine (fT4) hormone levels, the participants were divided into high and low-hormone-level groups. Despite decreased TSH and fT4 levels after the program, the factors influencing changes in each group were different. TSH levels were influenced by changes in the normalized low frequency (nLF) of heart rate variability and carbon monoxide (CO) from all the participants, and changes in body fat percentage, nLF, and nitrogen dioxide (NO2) exposure level in the high TSH group. fT4 levels were influenced by changes in body mass index (BMI), NO2 exposure, and particulate matter diameter of 10 µm or less (PM10) exposure in all participants. Changes in BMI and CO exposure influenced the low fT4 group. Lastly, changes in the exercise stress test affected the high fT4 group. Thus, the marine exercise retreat program affected euthyroid thyroid-related hormone levels, and influencing factors differ depending on the initial value of the hormone.
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Affiliation(s)
- Hangjin Byeon
- Department of Public Health, College of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Yesol Moon
- Department of Biomedical Science, Graduate School, Korea University, Seoul 02841, Republic of Korea
- Department of Preventive Medicine, College of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Seoeun Lee
- Department of Biomedical Science, Graduate School, Korea University, Seoul 02841, Republic of Korea
- Department of Preventive Medicine, College of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Gwang-Ic Son
- Department of Biomedical Science, Graduate School, Korea University, Seoul 02841, Republic of Korea
- Department of Preventive Medicine, College of Medicine, Korea University, Seoul 02841, Republic of Korea
| | - Eunil Lee
- Department of Public Health, College of Medicine, Korea University, Seoul 02841, Republic of Korea
- Department of Biomedical Science, Graduate School, Korea University, Seoul 02841, Republic of Korea
- Department of Preventive Medicine, College of Medicine, Korea University, Seoul 02841, Republic of Korea
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Effect of Hyperthyroidism Treatments on Heart Rate Variability: A Systematic Review and Meta-Analysis. Biomedicines 2022; 10:biomedicines10081982. [PMID: 36009529 PMCID: PMC9405700 DOI: 10.3390/biomedicines10081982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 07/28/2022] [Accepted: 08/11/2022] [Indexed: 11/17/2022] Open
Abstract
The reversibility of HRV abnormalities in hyperthyroidism remains contradictory. The design of this study involves conducting a systematic review and meta-analysis on the effect of antithyroid treatments on HRV in hyperthyroidism. PubMed, Cochrane, Embase, and Google Scholar were searched until 4 April 2022. Multiple reviewers selected articles reporting HRV parameters in treated and untreated hyperthyroidism. Independent data extraction by multiple observers was stratified by degree of hyperthyroidism for each HRV parameter: RR intervals, SDNN (standard deviation of RR intervals), RMSSD (square root of the mean difference of successive RR intervals), pNN50 (percentage of RR intervals with >50 ms of variation), total power (TP), LFnu (low-frequency normalized unit) and HFnu (high-frequency), VLF (very low-frequency), and LF/HF ratio. We included 11 studies for a total of 471 treated hyperthyroid patients, 495 untreated hyperthyroid patients, and 781 healthy controls. After treatment, there was an increase in RR, SDNN, RMSSD, pNN50, TP, HFnu, and VLF and a decrease in LFnu and LF/HF ratio (p < 0.01). Overt hyperthyroidism showed similar results, in contrast to subclinical hyperthyroidism. Compared with controls, some HRV parameter abnormalities persist in treated hyperthyroid patients (p < 0.05) with lower SDNN, LFnu, and higher HFnu, without significant difference in other parameters. We showed a partial reversibility of HRV abnormalities following treatment of overt hyperthyroidism. The improvement in HRV may translate the clinical cardiovascular benefits of treatments in hyperthyroidism and may help to follow the evolution of the cardiovascular morbidity.
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