Risk of atrial fibrillation in people with type 1 diabetes compared with matched controls from the general population: a prospective case-control study

Causal relationship between type I diabetes mellitus and atrial fibrillation: A Mendelian randomization study

Background

Patients with type 1 diabetes mellitus have been at heightened risk for developing atrial fibrillation. We aimed to investigate whether this association is causal using Mendelian randomization.

Methods

Using publicly available genome-wide association studies data, we selected single nucleotide polymorphisms significantly associated with type 1 diabetes mellitus as instrumental variables. We employed inverse variance-weighted, weighted median, MR-Egger regression, simple mode, and weighted mode methods within a two-sample Mendelian randomization framework to assess the causal relationship between type 1 diabetes mellitus and atrial fibrillation. We evaluated the pleiotropy and heterogeneity levels of the included genetic instruments using MR-PRESSO, MR-Egger intercept test, Cochran's Q test, funnel plots, and leave-one-out plots.

Results

Causal impact of type 1 diabetes mellitus on atrial fibrillation: Inverse variance weighted (odds ratio [OR] = 0.996, 95 % confidence interval [CI]: 0.985-1.007, P = 0.498). MR-Egger (OR = 1.000, 95 % CI: 0.985-1.016, P = 0.963). Weighted median (OR = 0.985, 95 % CI: 0.973-0.998, P = 0.022). Simple mode (OR = 1.007, 95 % CI: 0.974-1.040, P = 0.698). Weighted mode (OR = 0.995, 95 % CI: 0.984-1.005, P = 0.298). MR-Egger intercept test (P = 0.437). There was no evidence of pleiotropy among the genetic instrumental variables included in the analysis.

Conclusions

In Mendelian randomization analysis, we did not find evidence of a causal relationship between genetically determined type 1 diabetes mellitus in European ancestry populations and atrial fibrillation.

Cardiometabolic risk factors and disease trends for atrial fibrillation in individuals with type 1 diabetes: a nationwide registry study

OBJECTIVE

To investigate standardized incidence of atrial fibrillation (AF) in individuals with type 1 diabetes (T1DMM) compared with matched controls from the general population. Additionally, to examine optimal levels- and relative importance of risk factors associated with AF and numbers of risk factors necessary to reduce excess risk in individuals with T1DM.

RESEARCH DESIGN AND METHODS

The study included individuals with T1DM between 2001 and 2019 and matched controls without T1DM. The outcome of interest was the first occurrence of AF. Standardized incidence rates and Cox regression were used for analyzing incidence and risk associations.

RESULTS

The study comprises analyses of data from 36,069 persons with T1DM and 165,705 matched controls; average age 34.1; 43.2% women. Incidence rates per 100,000 person years for AF in persons with T1DM declined between 2001 and 2019 from 671 to 494; also in controls from 568 to 317. However, results shows that those without cardiovascular disease at baseline, did not display a similar rate reduction over time. During this period, people with T1DM had a 1.34-fold (95% CI 1.24-1.46) higher adjusted hazard for incident AF than controls when adjusting for sociodemographic factors. This hazard was attenuated to 0.95 (95% CI 0.87-1.03) after also accounting for coronary, cerebrovascular, kidney disease and heart failure; among those with T1DM. In those, with several risk factors at baseline, we observed a hazard ratio from 1.61 (95%, 1.07-2.43), and there was also an indication of clear risk reduction in those with zero risk factors, albeit non-significant (HR 0.60, 95% CI 0.35-1.04). In the T1DM cohort, the first available value of hemoglobin A1c, systolic blood pressure, body mass index and estimated glomerular filtration rate were each independently associated with incident AF and we noticed a clear linear risk increase for several cardiometabolic risk factors.

CONCLUSIONS

The crude incidence of AF was higher for persons with versus without T1DM, and declined significantly in both groups. Adjusting for data-derived predictors of AF attenuated higher risks, suggesting that the higher AF risk for persons with T1DM is driven by its common comorbidities.

Ubiquitin-specific protease 38 promotes atrial fibrillation in diabetic mice by stabilizing iron regulatory protein 2

BACKGROUND

Atrial fibrillation (AF) is a common cardiovascular disease often observed in diabetes mellitus, and there is currently no satisfactory therapeutic option. Ubiquitin-specific protease 38 (USP38) has been implicated in the degradation of numerous substrate proteins in the myocardium. Herein, we aim to investigate the role of USP38 in AF induced by diabetes.

METHODS

Cardiac-specific transgenic USP38 mice and cardiac-specific knockout USP38 mice were constructed, and streptozotocin was used to establish diabetic mouse model. Functional, electrophysiological, histologic, biochemical studies were performed.

RESULTS

The expression of USP38 was upregulated in atrial tissues of diabetic mice and HL-1 cells exposed to high glucose. USP38 overexpression increased susceptibility to AF, accompanied by aberrant expression of calcium-handling protein, heightened iron load and oxidation stress in diabetic mice. Conversely, USP38 deficiency reduced vulnerability to AF by hampering ferroptosis. Mechanistically, USP38 bound to iron regulatory protein 2 (IRP2), stabilizing it and remove K48-linked polyubiquitination chains, thereby increasing intracellular iron overload, lipid peroxidation, and ultimately contributing to ferroptosis. In addition, reduced iron overload by deferoxamine treatment alleviated oxidation stress and decreased vulnerability to AF in diabetic mice.

CONCLUSION

Overall, our findings reveal the detrimental role of USP38 in diabetes-related AF, manifested by increased level of iron overload and oxidation stress.

Effect modification of diabetic status on the association between exposure to particulate matter and cardiac arrhythmias in a general population: A systematic review and meta-analysis

Particulate matter (PM) has various health effects, including cardiovascular diseases. Exposure to PM and a diagnosis of diabetes mellitus (DM) have been associated with an increased risk of cardiac arrhythmias. However, no comprehensive synthesis has been conducted to examine the modifying effect of DM on the association between PM and arrhythmia events. Thus, the objectives of this review were to investigate whether the association of PM is linked to cardiac arrhythmias and whether DM status modifies its effect in the general population. The search was conducted on PubMed/MEDLINE and Embase until January 18, 2023. We included cohort and case-crossover studies reporting the effect of PM exposure on cardiac arrhythmias and examining the role of diabetes as an effect modifier. We used the DerSimonian and Laird random-effects model to calculate the pooled estimates. A total of 217 studies were found and subsequently screened. Nine studies met the inclusion criteria, and five of them were included in the meta-analysis. The participants numbered 4,431,452, with 2,556 having DM. Exposure to PM of any size showed a significant effect on arrhythmias in the overall population (OR 1.10, 95% CI 1.04-1.16). However, the effect modification of DM was not significant (OR 1.18 (95% CI 1.01-1.38) for DM; OR 1.08 (95% CI 1.02-1.14) for non-DM; p-value of subgroup difference = 0.304). Exposure to higher PM concentrations significantly increases cardiac arrhythmias requiring hospital or emergency visits. Although the impact on diabetic individuals is not significant, diabetic patients should still be considered at risk. Further studies with larger sample sizes and low bias are needed.

Assessing the association between triglyceride-glucose index and atrial fibrillation: a systematic review and meta-analysis

BACKGROUND

An essential relationship between insulin resistance (IR) and atrial fibrillation (AF) has been demonstrated. Among the methods used to assess IR, the triglyceride-glucose (TyG) index is the more straightforward, dimensionless, and low-cost tool. However, the possible usage of this index in clinical practice to predict and diagnose AF has yet to be determined and consolidated.

OBJECTIVE AND RATIONALE

Herein, we performed a systematic review and meta-analysis to assess the association between the TyG index and AF.

METHODS

Databases (PubMed, Embase, Scopus, and Web of Science) were systematically searched for studies evaluating the TyG index in AF. The inclusion criteria were observational studies investigating AF and TyG index correlation in individuals older than 18 years, while preclinical studies and those without the relevant data were excluded. Random effect meta-analyses comparing TyG levels between AF and non-AF cases, AF recurrence after radiofrequency ablation, and post-procedural AF were performed using standardized mean differences (SMD) with their matching 95% confidence intervals (CIs).

RESULTS

Our screening identified nine studies to be analyzed, including 6,171 participants including 886 with AF. The meta-analysis demonstrated that the TyG index resulted higher in patients with AF than non-AF counterparts (SMD 1.23, 95% CI 0.71 to 1.75, I2 98%, P < 0.001). Subgroup analysis showed the same results for post-procedure AF (SMD 0.99, 95% CI 0.78 to 1.20, I2 10%, P < 0.001) and post-ablation AF (SMD 1.25, 95% CI 1.07 to 1.43, I2 46%, P < 0.001), while no difference was found in population-based cohorts (SMD 1.45, 95% CI - 0.41 to 3.31, I2 100%, P = 0.13). Publication year (P = 0.036) and sample size (P = 0.003) showed significant associations with the effect size, using multivariable meta-regression.

CONCLUSION

The TyG index is an easy-to-measure surrogate marker of IR in patients with AF. Further clinical studies are warranted to demonstrate its ability for routine clinical use and as a screening tool.

Cardiac arrhythmias in STEMI patients in ICU: study on occurrence in first 48 h and correlation with age, sex, infarction site, and risk factors

Introduction

Acute myocardial infarction (AMI) is one of the leading causes of death in the developed world. The spread of the disease approaches three million people worldwide, with more than one million deaths in the United States annually. Myocardial ischemia and infarction can lead to electrophysiological and metabolic alterations that result in potentially fatal arrhythmias, some of which may be asymptomatic. About 90% of patients with AMI develop some form of arrhythmia during or immediately after the event, and in 25% of patients, these arrhythmias appear within the first 48 h. The most common cause of death in patients with AMI in pre-hospitalization is ventricular tachycardia/ventricular fibrillation (VT/VF).

Methods

A cross-sectional study targeting 150 patients with myocardial infarction attending tertiary hospital. According to certain acceptance and exclusion criteria.

Results

The sample consisted of 150 patients who suffered from heart infarction, the mean age of patients in the sample was 59.41 years with a standard deviation of 11.02 years and range of 28-90. Males constituted the largest portion of patients, with 112 males, that is 75%. The study identified that the anterior wall was the most frequent location for myocardial infarction among patients, with 64% of patients experiencing an infarction in this area. Additionally, ventricular fibrillation was the most commonly occurring arrhythmia, affecting 27% of myocardial infarction patients in the study.

Recommendations

One of the most important recommendations of our study is the necessity of keeping the patient under observation for at least 48 h after myocardial infarction within the hospital to monitor the ECG (Holter) in order to detect arrhythmias. Detection of arrhythmias in every patient with extensive anterior, lateral, or posterior myocardial infarction. And the need to know and take into account ventricular fibrillation and how to manage it in every patient with a heart infarction. And conducting future studies, including a larger number of patients, to study cardiac arrhythmias more precisely.

Diabetes mellitus and atrial fibrillation-from pathophysiology to treatment

Type 2 diabetes mellitus (T2DM) is a leading risk factor for cardiovascular complications around the globe and one of the most common medical conditions. Atrial fibrillation (AF) is the most common supraventricular arrhythmia, with a rapidly increasing prevalence. T2DM has been closely associated with the risk of AF development, identified as an independent risk factor. Regarding cardio-vascular complications, both AF and T2DM have been linked with high mortality. The underlying pathophysiology has not been fully determined yet; however, it is multifactorial, including structural, electrical, and autonomic pathways. Novel therapies include pharmaceutical agents in sodium-glucose cotransporter-2 inhibitors, as well as antiarrhythmic strategies, such as cardioversion and ablation. Of interest, glucose-lowering therapies may affect the prevalence of AF. This review presents the current evidence regarding the connection between the two entities, the pathophysiological pathways that link them, and the therapeutic options that exist.

Association of type 1 diabetes mellitus and risk of atrial fibrillation: Systematic review and meta-analysis

AIM

Whether type 1 diabetes mellitus (T1DM) could be regarded as an independent risk factor for atrial fibrillation (AF) risk remains unclear, and thus we aimed to elaborate on this association in our meta-analysis.

METHODS

We systematically searched the Pubmed, Embase, Cochrane Library and Web of Science databases up to August 2022 for studies that were related to T1DM and AF incidence. Hazard ratios (HRs) and 95% confidence intervals (CIs) from each study were pooled via a random-effects model.

RESULTS

A total of four cohort studies were involved in our meta-analysis. Our pooled results suggested that T1DM patients had a higher AF risk (HR = 1.30, 95%CI 1.15-1.47) than the control group. In the subgroup analysis, a higher AF incidence was also found in female T1DM patients (HR = 1.50, 95%CI 1.26-1.79) than that in male patients. Compared with T1DM patients over 65 years, those with < 65 years showed an increased risk of AF (HR = 1.45, 95%CI 1.21-1.74).

CONCLUSIONS

Our meta-analysis demonstrated that T1DM was an independent risk factor for AF development, but further studies should be performed to provide more convincing evidence.

Use of Diltiazem in Chronic Rate Control for Atrial Fibrillation: A Prospective Case-Control Study

Atrial fibrillation (AF) is a multifaceted disease requiring personalised treatment. The aim of our study was to explore the prognostic impact of a patient-specific therapy (PT) for rate control, including the use of non-dihydropyridine calcium channel blockers (NDDC) in patients with heart failure (HF) or in combination with beta-blockers (BB), compared to standard rate control therapy (ST), as defined by previous ESC guidelines. This is a single-centre prospective observational registry on AF patients who were followed by our University Hospital. We included 1112 patients on an exclusive rate control treatment. The PT group consisted of 125 (11.2%) patients, 93/125 (74.4%) of whom were prescribed BB + NDCC (±digoxin), while 85/125 (68.0%) were HF patients who were prescribed NDCC, which was diltiazem in all cases. The patients treated with a PT showed no difference in one-year overall survival compared to those with an ST. Notably, the patients with HF in ST had a worse prognosis (p < 0.001). To better define this finding, we performed three sensitivity analyses by matching each patient in the PT subgroups with three subjects from the ST cohort, showing an improved one-year survival of the HF patients treated with PT (p = 0.039). Our results suggest a potential outcome benefit of NDCC for rate control in AF patients, either alone or in combination with BB and in selected patients with HF.

The novel inflammatory biomarker GlycA and triglyceride-rich lipoproteins are associated with the presence of subclinical myocardial dysfunction in subjects with type 1 diabetes mellitus

BACKGROUND

Subjects with Type 1 diabetes mellitus (T1DM) have an increased incidence of heart failure (HF). Several pathophysiological mechanisms have been involved in its development. The aim of this study was to analyze the potential contribution of the advanced lipoprotein profile and plasma glycosylation (GlycA) to the presence of subclinical myocardial dysfunction in subjects with T1DM.

METHODS

We included subjects from a Danish cohort of T1DM subjects (Thousand & 1 study) with either diastolic and/or systolic subclinical myocardial dysfunction, and a control group without myocardial dysfunction, matched by age, sex and HbA1c. All underwent a transthoracic echocardiogram and an advanced lipoprotein profile obtained by using the NMR-based Liposcale® test. GlycA NMR signal was also analyzed. Systolic dysfunction was defined as left ventricular ejection fraction ≤ 45% and diastolic dysfunction was considered as E/e'≥12 or E/e' 8-12 + volume of the left atrium > 34 ml/m2. To identify a metabolic profile associated with the presence of subclinical myocardial dysfunction, a multivariate supervised model of classification based on least squares regression (PLS-DA regression) was performed.

RESULTS

One-hundred forty-six subjects had diastolic dysfunction and 18 systolic dysfunction. Compared to the control group, patients with myocardial dysfunction had longer duration of diabetes (p = 0.005), and higher BMI (p = 0.013), serum NTproBNP concentration (p = 0.001), systolic blood pressure (p < 0.001), albuminuria (p < 0.001), and incidence of advanced retinopathy (p < 0.001). The supervised classification model identified a specific pattern associated with myocardial dysfunction, with a capacity to discriminate patients with myocardial dysfunction from controls. PLS-DA showed that triglyceride-rich lipoproteins (TGRLs), such as VLDL (total VLDL particles, large VLDL subclass and VLDL-TG content) and IDL (IDL cholesterol content), as well as the plasma concentration of GlycA, were associated with the presence of subclinical myocardial dysfunction.

CONCLUSION

Proatherogenic TGRLs and the proinflammatory biomarker Glyc A are strongly associated to myocardial dysfunction in T1DM. These findings suggest a pivotal role of TGRLs and systemic inflammation in the development of subclinical myocardial dysfunction in T1DM.

Advanced glycation end products modulate electrophysiological remodeling of right ventricular outflow tract cardiomyocytes: A novel target for diabetes-related ventricular arrhythmogenesis

Diabetes mellitus is associated with cardiovascular disease and cardiac arrhythmia. Accumulation of advanced glycation end products closely correlates with cardiovascular complications through mitochondrial dysfunction or oxidative stress and evoke proliferative, inflammatory, and fibrotic reactions, which might impair cardiac electrophysiological characteristics and increase the incidence of cardiac arrhythmia. This study examined the mechanisms how advanced glycation end products may contribute to arrhythmogenesis of right ventricular outflow tract-a unique arrhythmogenic substrate. A whole-cell patch clamp, conventional electrophysiological study, fluorescence imaging, Western blot, and confocal microscope were used to study the electrical activity, and Ca2+ homeostasis or signaling in isolated right ventricular outflow tract myocytes with and without advanced glycation end products (100 μg/ml). The advanced glycation end products treated right ventricular outflow tract myocytes had a similar action potential duration as the controls, but exhibited a lower L-type Ca2+ current, higher late sodium current and transient outward current. Moreover, the advanced glycation end products treated right ventricular outflow tract myocytes had more intracellular Na+ , reverse mode Na+ -Ca2+ exchanger currents, intracellular and mitochondrial reactive oxygen species, and less intracellular Ca2+ transient and sarcoplasmic reticulum Ca2+ content with upregulated calcium homeostasis proteins and advanced glycation end products related signaling pathway proteins. In conclusions, advanced glycation end products modulate right ventricular outflow tract electrophysiological characteristics with larger late sodium current, intracellular Na+ , reverse mode Na+ -Ca2+ exchanger currents, and disturbed Ca2+ homeostasis through increased oxidative stress mediated by the activation of the advanced glycation end products signaling pathway.

The complex interplay between diabetes mellitus and atrial fibrillation

INTRODUCTION

: A growing body of evidence suggests that diabetes mellitus (DM) is associated with an increased risk of new-onset atrial fibrillation (AF) and contributes to suboptimal arrhythmia control and poor prognosis in patients with AF. The high prevalence of AF among patients with DM is primarily attributed to common risk factors, shared pathophysiological mechanisms, and associated atrial remodeling and autonomic dysfunction.

AREAS COVERED

: This comprehensive review covers the current data on the role of DM in the development and prognosis of AF. In addition, we review the impact of anti-DM medications on AF prevention and the role of anticoagulation in patients with coexisting DM and AF.

EXPERT OPINION

: DM is independently associated with new-onset AF, and the coexistence of these two conditions contributes to poor outcomes, from reduced quality of life to increased risks of thromboembolic events, heart failure, and mortality. Despite this strong link, the current evidence is insufficient to recommend routine screening for AF in patients with DM. Although some observations exist on preventing AF with anti-DM medications, randomized controlled trials are warranted to explore the proposed benefits of novel anti-DM medicines in reducing the risk of incident AF.

Risk of incident obstructive sleep apnoea in patients with type 1 diabetes: a population-based retrospective cohort study

AIMS/HYPOTHESIS

People with type 2 diabetes are at increased risk of developing obstructive sleep apnoea. However, it is not known whether people with type 1 diabetes are also at an increased risk of obstructive sleep apnoea. This study aimed to examine whether people with type 1 diabetes are at increased risk of incident obstructive sleep apnoea compared with a matched cohort without type 1 diabetes.

METHODS

We used a UK primary care database, The Health Improvement Network (THIN), to perform a retrospective cohort study between January 1995 and January 2018 comparing sleep apnoea incidence between patients with type 1 diabetes (exposed) and without type 1 diabetes (unexposed) (matched for age, sex, BMI and general practice). The outcome was incidence of obstructive sleep apnoea. Baseline covariates and characteristics were assessed at the start of the study based on the most recent value recorded prior to the index date. The Cox proportional hazards regression model was used to estimate unadjusted and adjusted hazard ratios, based on a complete-case analysis.

RESULTS

In total, 34,147 exposed and 129,500 matched unexposed patients were included. The median follow-up time was 5.43 years ((IQR 2.19-10.11), and the mean BMI was 25.82 kg/m2 (SD 4.33). The adjusted HR for incident obstructive sleep apnoea in patients with type 1 diabetes vs those without type 1 diabetes was 1.53 (95% CI 1.25, 1.86; p<0.001). Predictors of incident obstructive sleep apnoea in patients with type 1 diabetes were older age, male sex, obesity, being prescribed antihypertensive or lipid-lowering drugs, atrial fibrillation and depression.

CONCLUSIONS/INTERPRETATION

Individuals with type 1 diabetes are at increased risk of obstructive sleep apnoea compared with people without diabetes. Clinicians should suspect obstructive sleep apnoea in patients with type 1 diabetes if they are old, have obesity, are male, have atrial fibrillation or depression, or if they are taking lipid-lowering or antihypertensive drugs.

Metabolic Inflexibility as a Pathogenic Basis for Atrial Fibrillation

Atrial fibrillation (AF), the most common sustained arrhythmia, is closely intertwined with metabolic abnormalities. Recently, a metabolic paradox in AF pathogenesis has been suggested: under different forms of pathogenesis, the metabolic balance shifts either towards (e.g., obesity and diabetes) or away from (e.g., aging, heart failure, and hypertension) fatty acid oxidation, yet they all increase the risk of AF. This has raised the urgent need for a general consensus regarding the metabolic changes that predispose patients to AF. “Metabolic flexibility” aptly describes switches between substrates (fatty acids, glucose, amino acids, and ketones) in response to various energy stresses depending on availability and requirements. AF, characterized by irregular high-frequency excitation and the contraction of the atria, is an energy challenge and triggers a metabolic switch from preferential fatty acid utilization to glucose metabolism to increase the efficiency of ATP produced in relation to oxygen consumed. Therefore, the heart needs metabolic flexibility. In this review, we will briefly discuss (1) the current understanding of cardiac metabolic flexibility with an emphasis on the specificity of atrial metabolic characteristics; (2) metabolic heterogeneity among AF pathogenesis and metabolic inflexibility as a common pathological basis for AF; and (3) the substrate-metabolism mechanism underlying metabolic inflexibility in AF pathogenesis.

Atrial Fibrillation and Adverse Outcomes in Patients Undergoing Simultaneous Pancreas-Kidney Transplantation

BACKGROUND

There are no published data on atrial fibrillation (AF) in patients receiving simultaneous pancreas-kidney transplantation (SPKT). We explored the epidemiology and adverse outcomes of AF in SPKT recipients in this retrospective observational cohort study.

MATERIALS AND METHODS

All 200 SPKT recipients in Finland to date between March 2010 and April 2021 were included in the present study. Demographics, comorbidities, medications, and transplantation data were collected from the electronic patient records. Outcome measures included new-onset AF (NOAF), ischemic stroke, and death.

RESULTS

Median age was 42 years (interquartile range [IQR] 35-49), 69 (35%) were female, and median dialysis vintage was 13 months (IQR 9-19). Altogether 7 patients (4%) had a previous diagnosis of AF at baseline, and heart failure was independently associated with prior AF in the age-adjusted multivariable logistic regression analysis. After a median follow-up of 3 years (IQR 1-5), 2 patients (1%) were observed with incident NOAF, 4 (2%) with ischemic stroke, and 7 patients (4%) died. Prior AF or NOAF were not associated with cardiovascular adverse outcomes, mortality or graft outcomes.

CONCLUSIONS

We demonstrate a low prevalence and incidence of AF for the first time in this large observational study comprising all SPKT recipients in Finland to date.

Antiplatelet and Antithrombotic Therapy in Type I Diabetes Mellitus: Update on Current Data

Diabetes mellitus type 1 (T1DM) is an autoimmune disease characterized by a markedly elevated cardiovascular (CV) risk due to premature atherosclerosis. Previous studies have shown that intense glycemic control reduces the incidence of CV disease. Antiplatelet therapy is considered to be a very important therapy for secondary prevention of recurrent atherothrombotic events in patients with DM, while it may be considered for primary prevention in individuals with T1DM with additional CV risk factors. The aim of the present review is to summarize existing literature data regarding the thrombotic risk in T1DM patients and discuss current treatment strategies.

Medical therapies for prevention of cardiovascular and renal events in patients with atrial fibrillation and diabetes mellitus

Atrial fibrillation (AF), type 2 diabetes mellitus (DM), and chronic kidney disease (CKD) are three global epidemics with significant effects on morbidity and mortality. Diabetes is a risk factor for AF, and a risk factor for thromboembolism, comorbidity, and mortality when AF is present. The pathophysiology of diabetes-related AF and interrelationships with cardiovascular events and renal events is not fully understood but is in part related to structural, electrical, electromechanical, and autonomic remodelling. The current practice guidelines offer limited recommendations on the management of patients with AF (or risk of AF) and diabetes with its own heterogeneity for the prevention of cardiovascular and renal events. This document discusses possible clinical approaches for these patients. In the last decade, there have been major improvements for the prevention of stroke in AF patients with direct oral anticoagulants, which are preferable to vitamin K antagonists for stroke prevention in DM. Because of the increased risk rate for several cardiovascular adverse events in diabetic patients, a similar relative risk reduction generally translates into greater absolute risk reduction in the diabetic population. Recent trials with non-insulin diabetes drugs using glucagon-like peptide-1 agonists and sodium-glucose cotransporter-2 inhibitors showed a significant reduction for the risk of major adverse cardiovascular events in patients with type 2 DM. Sodium-glucose cotransporter-2 inhibitors also showed a large reduction in hospitalization for heart failure and renal events, which need to be more completely evaluated in patients with AF. Mechanisms, risks, and optimal management of AF patients with DM who have or are under risk of developing heart failure or CKD are also discussed in this document. The benefits of medical therapies for these patients still need to be put into perspective, and gaps in evidence on some of these issues are likely to be addressed in future years.

Glycation and Glycosylation in Cardiovascular Remodeling: Focus on Advanced Glycation End Products and O-Linked Glycosylations as Glucose-Related Pathogenetic Factors and Disease Markers

Glycation and glycosylation are non-enzymatic and enzymatic reactions, respectively, of glucose, glucose metabolites, and other reducing sugars with different substrates, such as proteins, lipids, and nucleic acids. Increased availability of glucose is a recognized risk factor for the onset and progression of diabetes-mellitus-associated disorders, among which cardiovascular diseases have a great impact on patient mortality. Both advanced glycation end products, the result of non-enzymatic glycation of substrates, and O-linked-N-Acetylglucosaminylation, a glycosylation reaction that is controlled by O-N-AcetylGlucosamine (GlcNAc) transferase (OGT) and O-GlcNAcase (OGA), have been shown to play a role in cardiovascular remodeling. In this review, we aim (1) to summarize the most recent data regarding the role of glycation and O-linked-N-Acetylglucosaminylation as glucose-related pathogenetic factors and disease markers in cardiovascular remodeling, and (2) to discuss potential common mechanisms linking these pathways to the dysregulation and/or loss of function of different biomolecules involved in this field.

Meta-analysis of type 1 diabetes mellitus and risk of cardiovascular disease

BACKGROUND

Individuals with diabetes have a high risk of cardiovascular disease (CVD). However, the association between type 1 diabetes mellitus (T1DM) and the risk of CVD has not been well addressed. This meta-analysis aimed to investigate the association between T1DM and CVD.

METHODS

We searched the PubMed and EMBASE for studies that examined the association between T1DM and CVD until October 2020. We calculated the pooled risk ratios (RRs) with confidence intervals (CIs) from individual studies based on a random-effects model.

RESULTS

We included 10 observational studies involving 166,027 patients with T1DM, and individuals were matched controls from the general population. Among T1DM patients, the RR of CVD was 5.09 (95% CI, 3.72-6.96), of coronary heart disease (CHD) was 9.38 (95% CI, 5.56-15.82), and of myocardial infarction was 6.37 (95% CI, 3.81-10.66). The RR of heart failure was 4.29 (95% CI, 3.54-5.19), of atrial fibrillation was 1.36 (95% CI, 1.17-1.59), and of stroke was 4.08 (95% CI, 3.42-4.86). Moreover, there was an increased RR among females for CHD, CVD, myocardial infarction, and stroke associated with T1DM.

CONCLUSIONS

This study suggests that T1DM is associated with an increased risk of several types of CVD. However, the possible mechanisms for the increased risk of CVD remain unclear.

Atrial fibrillation risk in patients suffering from type I diabetes mellitus. A review of clinical and experimental evidence

Atrial fibrillation (AF) and diabetes mellitus (DM) are commonly encountered in clinical practice. Although, the long term macrovascular and microvascular sequela of DM are well validated, the association between the less prevalent type 1 DM (T1DM) and atrial arrhythmogenesis is poorly understood. In the present review we highlight the current experimental and clinical data addressing this complex interaction. Animal studies support that T1DM, characterized by insulin deficiency and glycemic variability, impairs phosphatidylinositol 3‑kinase (PI3K)/protein kinase B signaling pathway. This pathway holds a central role in atrial electrical and structural remodeling responsible for arrhythmia initiation and maintenance. The molecular ''footprint'' of T1DM in atrial myocytes seems to involve a state of increased oxidative stress, impaired glucose transportation, ionic channel dysregulation and eventually fibrosis. On the contrary only a few clinical studies have examined the role of T1DM as an independent risk factor for AF development, and are discussed here. Further research is needed to solidify the real magnitude of this association and to investigate the clinical implications of PI3K molecular signaling pathway in atrial fibrillation management.

Sex, age, type of diabetes and incidence of atrial fibrillation in patients with diabetes mellitus: a nationwide analysis

BACKGROUND

There remain uncertainties regarding diabetes mellitus and the incidence of atrial fibrillation (AF), in relation to type of diabetes, and the interactions with sex and age. We investigated whether diabetes confers higher relative rates of AF in women compared to men, and whether these sex-differences depend on type of diabetes and age.

METHODS

All patients aged ≥ 18 seen in French hospitals in 2013 with at least 5 years of follow-up without a history of AF were identified and categorized by their diabetes status. We calculated overall and age-dependent incidence rates, hazard ratios, and women-to-men ratios for incidence of AF in patients with type 1 and type 2 diabetes (compared to no diabetes).

RESULTS

In 2,921,407 patients with no history of AF (55% women), 45,389 had prevalent type 1 diabetes and 345,499 had prevalent type 2 diabetes. The incidence rates (IRs) of AF were higher in type 1 or type 2 diabetic patients than in non-diabetics, and increased with advancing age. Among individuals with diabetes, the absolute rate of AF was higher in men than in women. When comparing individuals with and without diabetes, women had a higher adjusted hazard ratio (HR) of AF than men: adjusted HR 1.32 (95% confidence interval 1.27-1.37) in women vs. 1.12(1.08-1.16) in men for type 1 diabetes, adjusted HR 1.17(1.16-1.19) in women vs. 1.10(1.09-1.12) in men for type 2 diabetes.

CONCLUSION

Although men have higher absolute rates for incidence of AF, the relative rates of incident AF associated with diabetes are higher in women than in men for both type 1 and type 2 diabetes.

Oxidized CaMKII and O-GlcNAcylation cause increased atrial fibrillation in diabetic mice by distinct mechanisms

Diabetes mellitus (DM) and atrial fibrillation (AF) are major unsolved public health problems, and diabetes is an independent risk factor for AF. However, the mechanism(s) underlying this clinical association is unknown. ROS and protein O-GlcNAcylation (OGN) are increased in diabetic hearts, and calmodulin kinase II (CaMKII) is a proarrhythmic signal that may be activated by ROS (oxidized CaMKII, ox-CaMKII) and OGN (OGN-CaMKII). We induced type 1 (T1D) and type 2 DM (T2D) in a portfolio of genetic mouse models capable of dissecting the role of ROS and OGN at CaMKII and global OGN in diabetic AF. Here, we showed that T1D and T2D significantly increased AF, and this increase required CaMKII and OGN. T1D and T2D both required ox-CaMKII to increase AF; however, we did not detect OGN-CaMKII or a role for OGN-CaMKII in diabetic AF. Collectively, our data affirm CaMKII as a critical proarrhythmic signal in diabetic AF and suggest ROS primarily promotes AF by ox-CaMKII, while OGN promotes AF by a CaMKII-independent mechanism(s). These results provide insights into the mechanisms for increased AF in DM and suggest potential benefits for future CaMKII and OGN targeted therapies.

Burden of Cardiovascular Disease in Adult Patients with Type 1 Diabetes in the US

BACKGROUND AND OBJECTIVES

The burden imposed by cardiovascular disease (CVD) on patients with type 1 diabetes (T1D) in the US has not been thoroughly addressed. In a retrospective observational analysis of the Optum^® Clinformatics™ Data Mart database, the prevalence of CVD and cardiovascular risk factors (CVRF) as well as health economic outcomes were evaluated in adults with T1D.

METHODS

Patients with at least one T1D medical claim between January 1, 2016, and December 31, 2016, were divided into cohorts based on the presence of CVD and/or CVRF. Descriptive and multivariate analyses enabled comparisons of healthcare resource utilization and costs between the cohorts.

RESULTS

The analysis included 12,687 patients: CVD, 2871; CVRF, 5371; and no CVD/CVRF, 4445. The period prevalence of CVD and CVRF in the combined baseline and follow-up periods was 27% and 44%, respectively. Fewer patients in the no-CVD/CVRF cohort had a claim of a diabetes-related inpatient admission compared with the CVD cohort (8% vs. 26%, respectively; P < 0.001, standardized mean difference [SMD] > 0.1). Likewise, fewer patients with no CVD/CVRF visited the emergency department vs. those with CVRF or CVD (diabetes-related: 4% vs. 7% and 18%, respectively; P < 0.001, SMD > 0.1). Higher overall costs were observed for the CVD and CVRF vs. the no-CVD/CVRF cohort ($30,241 and $16,220, respectively, vs. $11,761; P < 0.05 and SMD ≥ 0.1 for both).

CONCLUSIONS

Cardiovascular comorbidities are common among US adults with T1D. Considering their significant economic burden, optimal management is of the utmost importance to improve patient outcomes and reduce healthcare costs.

Insulin Treatment Reduces Susceptibility to Atrial Fibrillation in Type 1 Diabetic Mice

Diabetes has been identified as an independent risk factor for atrial fibrillation (AF), the most common chronic cardiac arrhythmia. Whether or not glucose and insulin disturbances observed during diabetes enhance arrhythmogenicity of the atria, potentially leading to AF, is not well-known. We hypothesized that insulin deficiency and impaired glucose transport provide a metabolic substrate for the development and maintenance of AF during diabetes. Transesophageal atrial pacing was used to induce AF in healthy, streptozotocin-induced insulin-deficient type 1 diabetic, and insulin-treated diabetic mice. Translocation of insulin-sensitive glucose transporters (GLUTs) to the atrial cell surface was measured using a biotinylated photolabeling assay in the perfused heart. Fibrosis and glycogen accumulation in the atrium were measured using histological analysis. Diabetic mice displayed mild hyperglycemia, increased duration and frequency of AF episodes vs. age-matched controls (e.g., AF duration: 19.7 ± 6.8 s vs. 1.8 ± 1.1 s, respectively, p = 0.032), whereas insulin-treated diabetic animals did not. The translocation of insulin-sensitive GLUT-4 and -8 to the atrial cell surface was significantly downregulated in the diabetic mice (by 67 and 79%, respectively; p ≤ 0.001), and rescued by insulin treatment. We did not observe fibrosis or glycogen accumulation in the atria of diabetic mice. Therefore, these data suggest that insulin and glucose disturbances were sufficient to induce AF susceptibility during mild diabetes.

Atrial remodeling and atrial fibrillation in acquired forms of cardiovascular disease

Atrial fibrillation (AF) is prevalent in common conditions and acquired forms of heart disease, including diabetes mellitus (DM), hypertension, cardiac hypertrophy, and heart failure. AF is also prevalent in aging. Although acquired heart disease is common in aging individuals, age is also an independent risk factor for AF. Importantly, not all individuals age at the same rate. Rather, individuals of the same chronological age can vary in health status from fit to frail. Frailty can be quantified using a frailty index, which can be used to assess heterogeneity in individuals of the same chronological age. AF is thought to occur in association with electrical remodeling due to changes in ion channel expression or function as well as structural remodeling due to fibrosis, myocyte hypertrophy, or adiposity. These forms of remodeling can lead to triggered activity and electrical re-entry, which are fundamental mechanisms of AF initiation and maintenance. Nevertheless, the underlying determinants of electrical and structural remodeling are distinct in different conditions and disease states. In this focused review, we consider the factors leading to atrial electrical and structural remodeling in human patients and animal models of acquired cardiovascular disease or associated risk factors. Our goal is to identify similarities and differences in the cellular and molecular bases for atrial electrical and structural remodeling in conditions including DM, hypertension, hypertrophy, heart failure, aging, and frailty.

The present and future scope of real-world evidence research in diabetes: What questions can and cannot be answered and what might be possible in the future?

The last decade has witnessed an exponential growth in the opportunities to collect and link health-related data from multiple resources, including primary care, administrative, and device data. The availability of these "real-world," "big data" has fuelled also an intense methodological research into methods to handle them and extract actionable information. In medicine, the evidence generated from "real-world data" (RWD), which are not purposely collected to answer biomedical questions, is commonly termed "real-world evidence" (RWE). In this review, we focus on RWD and RWE in the area of diabetes research, highlighting their contributions in the last decade; and give some suggestions for future RWE diabetes research, by applying well-established and less-known tools to direct RWE diabetes research towards better personalized approaches to diabetes care. We underline the essential aspects to consider when using RWD and the key features limiting the translational potential of RWD in generating high-quality and applicable RWE. Only if viewed in the context of other study designs and statistical methods, with its pros and cons carefully considered, RWE will exploit its full potential as a complementary or even, in some cases, substitutive source of evidence compared to the expensive evidence obtained from randomized controlled trials.

Loss of insulin signaling may contribute to atrial fibrillation and atrial electrical remodeling in type 1 diabetes

Atrial fibrillation (AF) is prevalent in diabetes mellitus (DM); however, the basis for this is unknown. This study investigated AF susceptibility and atrial electrophysiology in type 1 diabetic Akita mice using in vivo intracardiac electrophysiology, high-resolution optical mapping in atrial preparations, and patch clamping in isolated atrial myocytes. qPCR and western blotting were used to assess ion channel expression. Akita mice were highly susceptible to AF in association with increased P-wave duration and slowed atrial conduction velocity. In a second model of type 1 DM, mice treated with streptozotocin (STZ) showed a similar increase in susceptibility to AF. Chronic insulin treatment reduced susceptibility and duration of AF and shortened P-wave duration in Akita mice. Atrial action potential (AP) morphology was altered in Akita mice due to a reduction in upstroke velocity and increases in AP duration. In Akita mice, atrial Na⁺ current (I_Na) and repolarizing K⁺ current (I_K) carried by voltage gated K⁺ (K_v1.5) channels were reduced. The reduction in I_Na occurred in association with reduced expression of SCN5a and voltage gated Na⁺ (Na_V1.5) channels as well as a shift in I_Na activation kinetics. Insulin potently and selectively increased I_Na in Akita mice without affecting I_K Chronic insulin treatment increased I_Na in association with increased expression of Na_V1.5. Acute insulin also increased I_Na, although to a smaller extent, due to enhanced insulin signaling via phosphatidylinositol 3,4,5-triphosphate (PIP₃). Our study reveals a critical, selective role for insulin in regulating atrial I_Na, which impacts susceptibility to AF in type 1 DM.

Cardiac Arrhythmias in Autoimmune Diseases

Autoimmune diseases (ADs) affect approximately 10% of the world's population. Because ADs are frequently systemic disorders, cardiac involvement is common. In this review we focus on typical arrhythmias and their pathogenesis, arrhythmia-associated mortality, and possible treatment options among selected ADs (sarcoidosis, systemic lupus erythematosus, scleroderma, type 1 diabetes, Graves' disease, rheumatoid arthritis, ankylosing spondylitis [AS], psoriasis, celiac disease [CD], and inflammatory bowel disease [IBD]). Rhythm disorders have different underlying pathophysiologies; myocardial inflammation and fibrosis seem to be the most important factors. Inflammatory processes and oxidative stress lead to cardiomyocyte necrosis, with subsequent electrical and structural remodeling. Furthermore, chronic inflammation is the pathophysiological basis linking AD to autonomic dysfunction, including sympathetic overactivation and a decline in parasympathetic function. Autoantibody-mediated inhibitory effects of cellular events (i.e., potassium or L-type calcium currents, M₂muscarinic cholinergic or β₁-adrenergic receptor signaling) can also lead to cardiac arrhythmia. Drug-induced arrhythmias, caused, for example, by corticosteroids, methotrexate, chloroquine, are also observed among AD patients. The most common arrhythmia in most AD presentations is atrial arrhythmia (primarily atrial fibrillation), expect for sarcoidosis and scleroderma, which are characterized by a higher burden of ventricular arrhythmia. Arrhythmia-associated mortality is highest among patients with sarcoidosis and lowest among those with AS; there are scant data related to mortality in patients with psoriasis, CD, and IBD.

Dose-response analysis between hemoglobin A1c and risk of atrial fibrillation in patients with and without known diabetes

Background

The relationship between serum hemoglobin A1c (HbA1c) and atrial fibrillation (AF) or postoperative AF (POAF) in coronary artery bypass (CABG) patients is still under debate. It is also unclear whether there is a dose-response relationship between circulating HbA1c and the risk of AF or POAF.

Methods and results

The Cochrane Library, PubMed, and EMBASE databases were searched. A robust-error meta-regression method was used to summarize the shape of the dose-response relationship. The RR and 95%CI were using a random-effects model. In total, 14 studies were included, totaling 17,914 AF cases among 352,325 participants. The summary RR per 1% increase in HbA1c was 1.16 (95% CI: 1.07–1.27). In the subgroup analysis, the summary RR was 1.13 (95% CI: 1.08–1.19) or 1.12 (95% CI: 1.05–1.20) for patients with diabetes or without known diabetes, respectively. The nonlinear analysis showed a nonlinear (P_nonlinear = 0.04) relationship between HbA1c and AF, with a significantly increased risk of AF if HbA1c was over 6.3%. However, HbA1c (per 1% increase) was not associated with POAF in patients with diabetes (RR: 1.13, P = 0.34) or without known diabetes (RR: 0.91, P = 0.37) among patients undergoing CABG.

Conclusion

Our results suggest that higher HbA1c was associated with an increased risk of AF, both in diabetes and in without diabetes or with unknown diabetes. However, no association was found between HbA1c and POAF in patients undergoing CABG. Further prospective studies with larger population sizes are needed to explore the association between serum HbA1c level and the risk of POAF.

Risk of atrial fibrillation in persons with type 2 diabetes and the excess risk in relation to glycaemic control and renal function: a Swedish cohort study

Background

To examine the incidence of atrial fibrillation in individuals with type 2 diabetes compared with age- and sex-matched controls from the general population and its variation in relation to glycaemic control and renal function.

Methods

A total of 421,855 patients with type 2 diabetes from the Swedish National Diabetes Registry and 2,131,223 controls from the Swedish Population Registry, matched for age, sex and county, were included and followed from January 1, 2001 to December 31, 2013.

Results

Overall, 8.9% of individuals with type 2 diabetes and 7.0% of controls were diagnosed with atrial fibrillation during follow-up, unadjusted incidence risk ratio (IRR) 1.35 (95% 1.33–1.36). Women < 55 years old with type 2 diabetes had an IRR of 2.36 (95% CI 2.10–2.66), in relation to controls, whereas the corresponding value for men < 55 years old with type 2 diabetes was IRR 1.78 (95% CI 1.67–1.90). In the fully adjusted Cox regression, the risk of type 2 diabetes on incident atrial fibrillation was 28% greater vs controls, hazard ratio (HR) 1.28 (95% CI 1.26–1.30), p < 0.0001. The excess risk of atrial fibrillation in individuals with type 2 diabetes increased with worsening glycaemic control and renal complications. For individuals with HbA1c ≤ 6.9% (≤ 52 mmol/mol) and normoalbuminuria the excess risk vs controls was still increased, adjusted HR 1.16 (95% CI 1.14–1.19); p < 0.0001.

Conclusions

Individuals with type 2 diabetes had an overall 35% higher risk of atrial fibrillation compared to age- and sex-matched controls from the general population. The excess risk for atrial fibrillation increased with renal complications or with poor glycaemic control. Individuals with type 2 diabetes with good glycaemic control and normoalbuminuria had slightly increased risk.

The Challenges of Identifying Environmental Determinants of Type 1 Diabetes: In Search of the Holy Grail

Type 1 diabetes is the result of autoimmune-mediated destruction and inflammation of the insulin-producing β-cells of the pancreas. The excess morbidity and mortality from its complications coupled with its increasing incidence emphasize the importance to better understand the etiology of this condition. It has a strong genetic component, but a genetic predisposition is not the sole contributor to disease development as only 30% to 50% of identical twins both develop the disease. In addition, there are multiple lines of evidence to support that environmental factors contribute to the pathogenesis of type 1 diabetes. Environmental risk factors that have been proposed include infections, dietary factors, air pollution, vaccines, location of residence, childhood obesity, family environment and stress. Researchers have conducted many observational studies to identify and characterize these potential environmental factors, but findings have been inconsistent or inconclusive. Many studies have had inherent methodological issues in recruitment, participation, defining cases and exposures, and/or data analysis which may limit the interpretability of findings. Identifying and addressing these limitations may allow for greatly needed advances in our understanding of type 1 diabetes. As such, the purpose of this article is to review and discuss the limitations of observational studies that aim to determine environmental risk factors for type 1 diabetes and propose recommendations to overcome them.

Pulmonary Vein Ganglia Are Remodeled in the Diabetic Heart

Background Cardiac autonomic neuropathy is thought to cause adverse cardiovascular effects in diabetes mellitus. Pulmonary vein ganglia ( PVG ), which have been implicated in normal and abnormal heart rhythm regulation, have not been fully investigated in type 1 diabetes mellitus (T1D). We examined the functional and anatomical effects of T1D on PVG and studied the details of T1D-induced remodeling on the PVG structure and function. Methods and Results We used a mouse model of T1D (Akita mouse), immunofluorescence, isolated Langendorff-perfused hearts, and mathematical simulations to explore the effects of T1D on PVG . Whole-mount atrial immunofluorescence of choline acetyltransferase and tyrosine hydroxylase labeling showed that sympathetic and parasympathetic somas of the PVG neurons were significantly hypotrophied in T1D hearts versus wild type. Stimulation of PVG in isolated Langendorff-perfused hearts caused more pronounced P-P interval prolongation in wild type compared with Akita hearts. Propranolol resulted in a comparable P-P prolongation in both phenotypes, and atropine led to more pronounced P-P interval shortening in wild type compared with Akita hearts. Numerical modeling using network simulations revealed that a decrease in the sympathetic and parasympathetic activities of PVG in T1D could explain the experimental results. Conclusions T1D leads to PVG remodeling with hypotrophy of sympathetic and parasympathetic cell bodies and a concomitant decrease in the PVG sympathetic and parasympathetic activities.

Gender Differences in Arrhythmias: Focused on Atrial Fibrillation

There are significant differences in clinical presentation and treatment of atrial fibrillation (AF) between women and men. The primary goal of AF management is to restore sinus rhythm and to prevent various complications, including stroke and heart failure. In many areas of AF, such as prevalence, clinical manifestations, morbidity, risk factors, pathophysiology, treatment strategies, and complications, gender-specific variability is observed and needs to be further addressed by large-scale population researches or randomized clinical trials, which help to promote the customization of AF treatment programs, hence to maximize the success rate of AF therapy in both sexes. This review highlights our current understanding of these gender differences in AF and how these differences affect treatment decisions on AF.

Pathological Role of Advanced Glycation End Products (AGEs) and their Receptor Axis in Atrial Fibrillation

Accumulating evidence has shown that the incidence of atrial fibrillation (AF) is higher in patients with diabetes, especially those with poor glycemic control or long disease duration. Nonenzymatic glycation of amino acids of proteins, lipids, and nucleic acids has progressed under normal aging process and/or diabetic condition, which could lead to the formation and accumulation of advanced glycation end products (AGEs). AGEs not only alter the tertiary structure and physiological function of macromolecules, but also evoke inflammatory and fibrotic reactions through the interaction of cell surface receptor for AGEs (RAGE), thereby being involved in aging-related disorders. In this paper, we briefly review the association of chronic hyperglycemia and type 1 diabetes with the risk of AF and then discuss the pathological role of AGE-RAGE axis in AF and its thromboembolic complications.

Risk Factors for Atrial Fibrillation in People With Type 1 Diabetes: An Observational Cohort Study of 36,258 Patients From the Swedish National Diabetes Registry

OBJECTIVE

This study identified variables associated with increased risk of atrial fibrillation in people with type 1 diabetes.

RESEARCH DESIGN AND METHODS

We performed a cohort study of people with type 1 diabetes from the Swedish National Diabetes Registry followed up between 1 January 2001 and 31 December 2013. Median follow-up was 9.7 years (interquartile range 5.2-13.0). The association between potential risk factors and incident atrial fibrillation was investigated using adjusted Cox regression. To compare the impact of each risk factor, the gradient of risk per 1 SD was estimated.

RESULTS

In this cohort of 36,258 patients with type 1 diabetes, 749 developed atrial fibrillation during follow-up. Older age, male sex, renal complications, increased BMI and HbA_1c, coronary artery disease, heart failure, and heart valve disease increased the risk of atrial fibrillation. Age, signs of renal dysfunction with macroalbuminuria, and decreasing estimated glomerular filtration rate were associated with the highest gradient of risk for atrial fibrillation. High blood pressure, severe obesity (BMI >35 kg/m²), and elevated levels of HbA_1c (>9.6%) were associated with increased risk, but no associations were found with hyperlipidemia or smoking.

CONCLUSIONS

The most prominent risk factors for atrial fibrillation in people with type 1 diabetes were older age, cardiovascular comorbidities, and renal complications, while obesity, hypertension, and hyperglycemia had more modest affects.

The Association Between Diabetes Mellitus and Atrial Fibrillation: Clinical and Mechanistic Insights

A number of clinical studies have reported that diabetes mellitus (DM) is an independent risk factor for Atrial fibrillation (AF). After adjustment for other known risk factors including age, sex, and cardiovascular risk factors, DM remains a significant if modest risk factor for development of AF. The mechanisms underlying the increased susceptibility to AF in DM are incompletely understood, but are thought to involve electrical, structural, and autonomic remodeling in the atria. Electrical remodeling in DM may involve alterations in gap junction function that affect atrial conduction velocity due to changes in expression or localization of connexins. Electrical remodeling can also occur due to changes in atrial action potential morphology in association with changes in ionic currents, such as sodium or potassium currents, that can affect conduction velocity or susceptibility to triggered activity. Structural remodeling in DM results in atrial fibrosis, which can alter conduction patterns and susceptibility to re-entry in the atria. In addition, increases in atrial adipose tissue, especially in Type II DM, can lead to disruptions in atrial conduction velocity or conduction patterns that may affect arrhythmogenesis. Whether the insulin resistance in type II DM activates unique intracellular signaling pathways independent of obesity requires further investigation. In addition, the relationship between incident AF and glycemic control requires further study.

Atrial fibrillation and type 2 diabetes: Prevalence, etiology, pathophysiology and effect of anti-diabetic therapies

New-onset atrial fibrillation (NAF) is increased in the type 2 diabetic patient because of the presence of the metaboli syndrome and increased sympathetic activity. This results in inflammation, endothelial dysfunction and myocardial steatosis which, in turn, lead to atrial fibrosis and dilatation. The end result is the development of structural and electrical atrial remodeling. Drugs that lower insulin resistance, particularly pioglitazone, decrease the incidence of NAF while drugs that, through hypoglycaemia, stimulate the sympathetic nervous system, insulin and secretagogues, increase the incidence of NAF. Currently there is no evidence that GLP-1 agonists, SGLT2 inhibitors and DPP-4 inhibitors either accelerate or decelerate the development of NAF.

Concerns about clinical efficacy and safety of warfarin in diabetic patients with atrial fibrillation

Atrial fibrillation (AF) is one of the most common arrhythmias in elderly people. The risk of thromboembolic stroke is increased in AF patients, especially those with diabetes. Anticoagulant therapy, such as warfarin and non-vitamin K oral anticoagulants (NOACs), is recommended for diabetic patients with AF. However, recent guidelines do not preferentially recommend NOACs over warfarin for diabetic patients. Variability of glycemic control in diabetic patients could affect the pharmacokinetics and anticoagulant activity of warfarin, therefore, the risk-benefit balance of warfarin is prone to be compromised in diabetic patients with AF. Furthermore, since warfarin inhibits the vitamin K-dependent gamma-glutamyl carboxylation of proteins, including osteocalcin and matrix Gla protein, use of warfarin may increase the risk of osteoporotic bone fracture and vascular calcification, both of which are the leading causes of morbidity that diminish the quality of life in diabetic patients. Even though the cost of NOACs is high, NOACs may be preferable to warfarin for the treatment of diabetic patients with AF.

Diabetes and Arrhythmias: Pathophysiology, Mechanisms and Therapeutic Outcomes

The prevalence of diabetes is rapidly increasing and closely associated with cardiovascular morbidity and mortality. While the major cardiovascular complication associated with diabetes is coronary artery disease, it is becoming increasingly apparent that diabetes impacts the electrical conduction system in the heart, resulting in atrial fibrillation, and ventricular arrhythmias. The relationship between diabetes and arrhythmias is complex and multifactorial including autonomic dysfunction, atrial and ventricular remodeling and molecular alterations. This review will provide a comprehensive overview of the link between diabetes and arrhythmias with insight into the common molecular mechanisms, structural alterations and therapeutic outcomes.

Gender differences in diabetes self-care in adults with type 1 diabetes: Findings from the T1D Exchange clinic registry

AIMS

To evaluate gender differences in diabetes self-care components including glycemic, blood pressure and lipid control, utilization of diabetes technologies and acute diabetes complications in adults with type 1 diabetes.

METHODS

A total of 9,481 participants >18 years were included in the analysis, 53% were female. Variables of interest included glycemic control measured by HbA1c, systolic/diastolic blood pressures, presence of dyslipidemia, insulin delivery modality, and rates of acute complications.

RESULTS

Glycemic control was similar in women and men (mean HbA1c in both groups: 8.1% ± 1.6% (64 ± 16 mmol/mol), (p = 0.54). More women used insulin pump therapy (66% vs. 59%, p < 0.001) but use of sensor technology was similar (p < = 0.42). Women had higher rates of diabetic ketoacidosis (DKA) (5% vs. 3%, p < 0.001) and eating disorders (1.7% vs. 0.1%, p < 0.001). Severe hypoglycemia rates were not different between men and women (p = 0.42). Smoking (6% vs 4%, p < 0.001), systolic (125 ± 14.2 vs. 121 ± 14.4, p < 0.001) and diastolic blood pressure (73.3 ± 9.5 vs. 72.2 ± 9.3, p < 0.001) and rate of dyslipidemia (28% vs. 23%, p < 0.001) were higher in men.

CONCLUSION

While glycemic control in type 1 diabetes was similar regardless of gender, rates of DKA and eating disorders were higher in women while rates of smoking, hypertension and dyslipidemia were higher in men.

Data Linking Diabetes Mellitus and Atrial Fibrillation-How Strong Is the Evidence? From Epidemiology and Pathophysiology to Therapeutic Implications

According to estimates, around 5% of the world population has hazel eyes. And there are about as many people with diabetes mellitus (DM). Red hair occurs naturally in up to 2% of the human population. And about as many people are estimated to have atrial fibrillation (AF). If a hazel eyed person with red hair does not surprise us, should a diabetic patient with AF? Accumulating epidemiologic data suggest, however, that the DM-AF association may be more than a simple coincidence. But, how strong is this evidence? Experimental studies bring evidence for a DM-induced atrial proarrhythmic remodelling. But how relevant are these data for the clinical setting? In this review, we aim to provide a critical analysis of the existing clinical and experimental, epidemiologic, and mechanistic data that bridge DM and AF, we emphasize a number of questions that remain to be answered, and we identify hotspots for future research. The therapeutic implications of the DM-AF coexistence are also discussed, with a focus on rhythm control and on conventional and DM-specific upstream therapies for AF management.

A Machine Learning Aided Systematic Review and Meta-Analysis of the Relative Risk of Atrial Fibrillation in Patients With Diabetes Mellitus

Background: Meta-analysis is a widely used tool in which weighted information from multiple similar studies is aggregated to increase statistical power. However, the exponential growth of publications in key areas of medical science has rendered manual identification of relevant studies increasingly time-consuming. The aim of this work was to develop a machine learning technique capable of robust automatic study selection for meta-analysis. We have validated this approach with an up-to-date meta-analysis to investigate the association between diabetes mellitus (DM) and new-onset atrial fibrillation (AF). Methods: The PubMed online database was searched from 1960 to September 2017 where 4,177 publications that mentioned both DM and AF were identified. Relevant studies were selected as follows. First, publications were clustered based on common text features using an unsupervised K-means algorithm. Clusters that best matched the selected set of potentially relevant studies (a "training" set of 139 articles) were then identified by using maximum entropy classification. The 139 articles selected automatically on this basis were screened manually to identify potentially relevant studies. To determine the validity of the automated process, a parallel set of studies was also assembled by manually screening all initially searched publications. Finally, detailed manual selection was performed on the full texts of the studies in both sets using standard criteria. Quality assessment, meta-regression random-effects models, sensitivity analysis and publication bias assessment were then conducted. Results: Machine learning-assisted screening identified the same 29 studies for meta-analysis as those identified by using manual screening alone. Machine learning enabled more robust and efficient study selection, reducing the number of studies needed for manual screening from 4,177 to 556 articles. A pooled analysis using the most conservative estimates indicated that patients with DM had ~49% greater risk of developing AF compared with individuals without DM. After adjusting for three additional risk factors i.e., hypertension, obesity and heart disease, the relative risk was 23%. Using multivariate adjusted models, the risk for developing AF in patients with DM was similar for all DM subtypes. Women with DM were 24% more likely to develop AF than men with DM. The risk for new-onset AF in patients with DM has also increased over the years. Conclusions: We have developed a novel machine learning method to identify publications suitable for inclusion in meta-analysis.This approach has the capacity to provide for a more efficient and more objective study selection process for future such studies. We have used it to demonstrate that DM is a strong, independent risk factor for AF, particularly for women.

Cardiovascular outcome in type 2 diabetes and atrial fibrillation

Diabetes is an independent risk factor for atrial fibrillation (AF). Frequently, it is part of the metabolic syndrome cluster, which includes obesity and hypertension that are independently associated with AF. The risk appears to be higher with longer duration of diabetes and inadequate glycemic control. Patients with diabetes and AF have a substantially increased risk of death and serious cardiovascular complications compared with those in sinus rhythm. Conversely, good metabolic control appears to be associated with maintenance of rhythm after successful therapeutic conversion to sinus rhythm by catheter ablation or electrical cardioconversion of AF. AF puts patients with type 2 diabetes at a high risk of cardiovascular complications and death, which could be successfully addressed by new classes of antidiabetic agents such as incretin analogues or sglt-2 inhibitors. Thus, a diagnostic strategy that addresses the increased risk for AF is urgently recommended, in addition to diabetes monitoring in routine outpatient practice. In order to prevent thromboembolic complications, which frequently determine the prognosis for this patient population, appropriate anticoagulation remains the mainstay of therapy, whereas the prognostic value of reinstalling sinus rhythm awaits further evidence.

Supraventricular tachycardia as a complication of severe diabetic ketoacidosis in an adolescent with new-onset type 1 diabetes

Diabetic ketoacidosis (DKA) is one of the most common causes of morbidity and mortality in new-onset type 1 diabetes (T1D). Supraventricular tachycardia (SVT), however, is a very rare complication of DKA. We present the case of a patient with new-onset T1D who presented with DKA. He received intravenous fluid resuscitation, insulin and potassium supplementation and subsequently developed SVT, confirmed on a 12-lead electrocardiograph despite a structurally normal heart. Vagal manoeuvres and adenosine failed to restore sinus rhythm, but flecainide was successful. We conclude that SVT can occur as a complication of DKA, including in new-onset T1D. Our case is the first of this phenomenon occurring in new-onset childhood diabetes, as the few prior documented cases had established diabetes. Furthermore, a combination of potassium derangement, hypophosphataemia and falling magnesium levels may have precipitated the event.