The Impact of Metabolic Syndrome on the Incidence of Atrial Fibrillation: A Nationwide Longitudinal Cohort Study in South Korea

Association between metabolic syndrome and kidney cancer risk: a prospective cohort study

BACKGROUND

Kidney cancer has become known as a metabolic disease. However, there is limited evidence linking metabolic syndrome (MetS) with kidney cancer risk. This study aimed to investigate the association between MetS and its components and the risk of kidney cancer.

METHODS

UK Biobank data was used in this study. MetS was defined as having three or more metabolic abnormalities, while pre-MetS was defined as the presence of one or two metabolic abnormalities. Hazard ratios (HRs) and 95% confidence intervals (CIs) for kidney cancer risk by MetS category were calculated using multivariable Cox proportional hazards models. Subgroup analyses were conducted for age, sex, BMI, smoking status and drinking status. The joint effects of MetS and genetic factors on kidney cancer risk were also analyzed.

RESULTS

This study included 355,678 participants without cancer at recruitment. During a median follow-up of 11 years, 1203 participants developed kidney cancer. Compared to the metabolically healthy group, participants with pre-MetS (HR= 1.36, 95% CI: 1.06-1.74) or MetS (HR= 1. 70, 95% CI: 1.30-2.23) had a significantly greater risk of kidney cancer. This risk increased with the increasing number of MetS components (P for trend < 0.001). The combination of hypertension, dyslipidemia and central obesity contributed to the highest risk of kidney cancer (HR= 3.03, 95% CI: 1.91-4.80). Compared with participants with non-MetS and low genetic risk, those with MetS and high genetic risk had the highest risk of kidney cancer (HR= 1. 74, 95% CI: 1.41-2.14).

CONCLUSIONS

Both pre-MetS and MetS status were positively associated with kidney cancer risk. The risk associated with kidney cancer varied by combinations of MetS components. These findings may offer novel perspectives on the aetiology of kidney cancer and assist in designing primary prevention strategies.

Left Atrial Strain Insights in Atrial Fibrillation and the Interplay with Metabolic Syndrome

INTRODUCTION

Understanding the interplay between metabolic syndrome and left atrial (LA) function is crucial, especially in patients newly diagnosed with atrial fibrillation (AF). We evaluated the association between subclinical atrial function and metabolic syndrome in patients diagnosed with new-onset AF.

METHODS

A retrospective analysis was conducted on 220 patients, aged between 20 and 100 years, who were newly diagnosed with AF. These patients were divided into two groups based on the presence or absence of metabolic syndrome. LA reservoir strain, a measure of LA function, was assessed using transthoracic echocardiography. Statistical methods, including receiver operating characteristic (ROC) curve and logistic regression analyses, were employed to evaluate the association between LA strain and metabolic syndrome.

RESULTS

Among the 220 patients, 108 had metabolic syndrome and displayed more adverse clinical characteristics. The LA reservoir strain was significantly lower in this group (9.7% ± 5.2% vs. 12.0% ± 5.8%, p = 0.003). ROC curve analysis identified 9.3% as the optimal cutoff value for predicting metabolic syndrome, with a sensitivity of 50.9% and specificity of 70.5%. Further, multivariate analysis confirmed that an LA reservoir strain below 9.3% was independently linked to metabolic syndrome (odds ratio 4.261, 95% confidence interval 1.134-16.009, p = 0.032).

CONCLUSIONS

The findings reveal a significant association between lower LA reservoir strain values and the presence of metabolic syndrome in patients newly diagnosed with AF. An LA strain value below 9.3% serves as a critical diagnostic and prognostic indicator, highlighting its clinical importance in managing patients with AF.

Prevalence of metabolic syndrome and its association with atrial arrhythmias in patients with implanted permanent pacemaker for cardiac conduction abnormality

The objective of the study was to find the prevalence of metabolic syndrome along with identifying the atrial arrhythmias, QTC interval, and coronary artery disease among these patients during follow-ups. Among 171 subjects who were implanted with permanent pacemakers, metabolic syndrome was present in 90 (52.6 %). Prevalence of Arrhythmias was 49 (28.7 %), atrial tachycardia (AT)/atrial fibrillation (AF) was seen in 29 (17 %) patients. Our study showed that there is a strong association between metabolic syndrome and atrial arrhythmias. Metabolic syndrome, age, coronary artery disease and Systolic blood pressure were good independent predictors of atrial arrhythmias among patients with pacemaker implantation.

Metabolic Syndrome and Atrial Fibrillation: Different Entities or Combined Disorders

Obesity, hypertension, insulin resistance, and dyslipidemia are all clusters of an entity called "Metabolic Syndrome". The global trends of this syndrome's incidence/prevalence continue to increase reciprocally, converting it into a massive epidemic problem in the medical community. Observing the risk factors of atrial fibrillation, a medical condition that is also converted to a scourge, almost all parts of the metabolic syndrome are encountered. In addition, several studies demonstrated a robust correlation between metabolic syndrome and the occurrence of atrial fibrillation. For atrial fibrillation to develop, a combination of the appropriate substrate and a trigger point is necessary. The metabolic syndrome affects the left atrium in a multifactorial way, leading to atrial remodeling, thus providing both the substrate and provoking the trigger needed, which possibly plays a substantial role in the progression of atrial fibrillation. Due to the remodeling, treatment of atrial fibrillation may culminate in pernicious sequelae, such as repeated catheter ablation procedures. A holistic approach of the patient, with simultaneous treatment of both entities, is suggested in order to ensure better outcomes for the patients.

Association of lipid composition and unsaturated fatty acids of VLDL with atrial remodeling in metabolic syndrome

Subjects with metabolic syndrome (MetS) commonly have atrial remodeling, which indicates a risk for atrial fibrillation. This study determined MetS-related changes in lipid components in very-low-density lipoprotein (VLDL), which has been shown to cause atrial remodeling, the effect of statins on these changes, and the correlation between atrial remodeling and VLDL lipid compositions. Blood samples were collected from 12 non-MetS and 27 sex- and age-matched MetS subjects. Fourteen patients with MetS (MetS-off statin) discontinued statin therapy 14 days before the study, while the remaining 13 remained on it (MetS-on statin). The VLDLs were isolated and processed for mass-based lipid profiling. Lipidomic analyses were performed and associated with atrial remodeling markers measured using standard echocardiography and electrocardiography. Compared with the VLDL components of the non-MetS group, glucosyl/galactosyl ceramide, lyso-phosphatidylcholine, lyso-phosphatidylethanolamine, and triglycerides were enriched in the MetS-off statin group. Statin therapy attenuated all abnormally abundant lipid classes in MetS, except for triglycerides. In addition, lyso-phosphatidylcholine, lyso-phosphatidylethanolamine, and triglycerides were significantly correlated with atrial dilatation, and the latter two were also correlated with the PR interval. Enrichment of double bonds, which indicate unsaturated fatty acids, was also significantly correlated with atrial remodeling and P-wave duration. This study suggests that the pathological lipid payload of MetS-VLDL may contribute to atrial remodeling in patients.

Different Impact of Metabolic Syndrome on the Risk of Incidence of the Peripheral Artery Disease and the Venous Thromboembolism: A Nationwide Longitudinal Cohort Study in South Korea

Background

Limited data is available between metabolic syndrome (MetS) and the development of peripheral arterial disease (PAD) or venous thromboembolism (VTE) in the Asian population. We investigated the incidence of PAD and VTE according to the prevalence of MetS and evaluated the impact of individual components in MetS on the development of PAD and VTE using Korean national data.

Methods

Data obtained from national health screening examinations of the Korean National Health Insurance Service from January 1, to December 31, 2009. In total, 9,927,538 participants, 7,830,602 participants were included in this study and the incidence rate of PAD and VTE was investigated retrospectively during a 7-year follow-up. Using the National Cholesterol Education Program Adult Treatment Panel III criteria, patients were placed into one of three groups depending on MetS component numbers: 0 (normal), 1-2 (Pre-MetS), or 3-5 (MetS).

Results

The incidence rates of PAD and VTE in MetS were 2.25% and 0.71%, respectively. After multivariable adjustment, the risk of PAD was significantly associated with MetS (hazard ratio (HR) 1.45, 95% confidence interval (CI) 1.42-1.49), the risk of VTE was not associated with MetS (HR 1.01, 95% CI 0.96-1.05). When subgroup analyses were conducted according to MetS components, elevated fasting glucose (HR 1.26, 95% CI 1.23-1.27), abdominal obesity (HR 1.15, 95% CI 1.12-1.17), and elevated blood pressure (HR 1.13, 95% CI 1.12-1.15) were the most related to PAD. Abdominal obesity (HR 1.104, 95% CI 1.064-1.146) was associated with an increased risk of VTE.

Conclusions

MetS was significantly associated with an increased incidence rate of PAD among the general Korean population. On the other hand, MetS was not associated with the VTE incidence rate. Of the MetS components, only abdominal obesity was a significant predictor of VTE.

Early atrial remodeling predicts the risk of cardiovascular events in patients with metabolic syndrome: a retrospective cohort study

Background

This study aims to assess the prevalence of atrial cardiomyopathy (ACM) in patients with new-onset metabolic syndrome (MetS) and investigate whether ACM could be a predictor of hospital admission for cardiovascular (CV) events.

Methods

Patients with MetS who were free of clinically proven atrial fibrillation and other CV diseases (CVDs) at baseline were included in the present study. The prevalence of ACM was compared between MetS patients with and without left ventricular hypertrophy (LVH). The time to first hospital admission for a CV event between subgroups was assessed using the Cox proportional hazard model.

Results

A total of 15,528 MetS patients were included in the final analysis. Overall, LVH patients accounted for 25.6% of all newly diagnosed MetS patients. ACM occurred in 52.9% of the cohort and involved 74.8% of LVH patients. Interestingly, a significant percentage of ACM patients (45.4%) experienced MetS without LVH. After 33.2 ± 20.6 months of follow-up, 7,468 (48.1%) patients had a history of readmission due to CV events. Multivariable Cox regression analysis revealed that ACM was associated with an increased risk of admission for CVDs in the MetS patients with LVH [hazard ratio (HR), 1.29; 95% confidence interval (CI), 1.142-1.458; P < 0.001]. Likewise, ACM was found to be independently associated with hospital readmission due to CVD-related events in MetS patients without LVH (HR, 1.175; 95% CI, 1.105-1.250; P < 0.001).

Conclusion

ACM is a marker of early myocardial remodeling and predicts hospitalization for CV events in patients with MetS.

Shensong Yangxin attenuates metabolic syndrome-induced atrial fibrillation via inhibition of ferroportin-mediated intracellular iron overload

BACKGROUND

Shensong Yangxin (SSYX) is a traditional Chinese medicine been widely used clinically to treat various arrhythmias including atrial fibrillation (AF). However, the role and precise mechanism of SSYX in MS-induced AF have not yet been elucidated.

PURPOSE

To elucidate the protective effects of SSYX on MS-induced AF and its possible mechanisms of action.

METHODS

Male Wistar rats (180-220 g) were fed a 16-week high-carbohydrate, high-fat (HCHF) diet together with 25% fructose in drinking water to produce a MS model. Low-concentration (SSYX-L, 0.4 g/kg) and high-concentration (SSYX-H, 0.8 g/kg) of SSYX were given by daily gavage 8-weeks following HCHF diet for 8-weeks. In vivo electrophysiological study, histological analysis, RNA-sequence (RNA-Seq) and gene ontology (GO) analysis, qRT-PCR and western blot were performed.

RESULTS

Both low-concentration and high-concentration of SSYX could inhibit MS-induced AF susceptibility, electrical remodeling and structural remodeling. Results from RNA-sequence analysis revealed intracellular iron homeostasis mediated the protective effect of SSYX against MS. In vivo and in vitro experiments both demonstrated that SSYX up-regulated ferroportin (Fpn) expression and ameliorated intracellular iron overload induced by MS. To verified whether Fpn is the target of SSYX and intracellular iron overload mediated the protective effect of SSYX against MS, adeno-associated virus type 9 (AAV9) delivery system was used. Knocking down Fpn (AAV9-shFpn) markedly aggravated the reactive oxygen species (ROS) production, electrical remodeling and atrial fibrosis induced by MS, leading to a further increase of AF susceptibility induced by MS.

CONCLUSION

Our study demonstrated for the first time that SSYX reduced AF susceptibility, inhibited electrical remodeling and structural remodeling via up-regulating Fpn, decreasing intracellular iron overload and reducing ROS production. These results suggest that SSYX might be a potential therapeutic agent for the treatment of MS-induced AF.

The influence of metabolic syndrome on atrial fibrillation recurrence: five-year outcomes after a single cryoballoon ablation procedure

BACKGROUND

Metabolic syndrome (MetS) has been reported as a risk factor of atrial fibrillation (AF) recurrence after radiofrequency catheter ablation. This study aimed to investigate the long-term influence of MetS on paroxysmal AF recurrence after a single cryoballoon ablation procedure, which was scarcely investigated yet in Chinese population.

METHODS

In total, 137 paroxysmal AF patients who had successfully completed a single cryoballoon ablation procedure at Fuwai Hospital, Beijing, China from December 2013 to October 2015 were enrolled. Excepting for patients with AF recurrence, all patients were followed up for no less than five years. Independent predictors of AF recurrence were determined by Cox proportional hazards regression analysis.

RESULTS

Among 137 paroxysmal AF patients, 91 patients (66.4%) had successfully achieved overall five-year follow-up after a single cryoballoon ablation procedure, and 44 patients (32.1%) had MetS. Patients with MetS had a significant lower incidence of freedom from AF recurrence than those without MetS (50.0% vs. 74.2%, log-rank P < 0.01) during the five-year follow-up. MetS (HR = 1.95, 95% CI: 1.069−3.551, P = 0.030) was an independent predictor of AF recurrence after adjusting for multiple factors. After the second year post cryoballoon ablation procedure, the recurrence rate of AF gradually increased in patients with MetS, in contrast, decreased recurrence rate of AF in patients without MetS.

CONCLUSIONS

MetS is an independent predictor for five-year AF recurrence after a single cryoballoon ablation procedure in paroxysmal AF patients. Combination therapy of AF and MetS may improve the long-term outcomes of AF patients.

Obesity phenotypes and their relationships with atrial fibrillation

Background

This study assessed the associations of metabolic obesity phenotypes with the risk of atrial fibrillation (Afib).

Methods

This prospective cohort study categorized Taiwanese adults according to their body mass index (BMI) and metabolic health status at baseline. We assigned the participants to the underweight (BMI < 18.5 kg/m²), normal weight (BMI = 18.5-23.9 kg/m²), and overweight/obesity groups (BMI ≥ 24 kg/m²). Metabolically healthy was defined as absence of hypertension, diabetes, and hyperlipidemia and the presence of healthy metabolic profiles.

Results

In total, 5,742 adults were included. During a median follow-up of 13.7 years, 148 patients developed Afib. Compared to the metabolically healthy normal weight group, the risk of Afib was significantly higher than those in the metabolically unhealthy overweight/obesity (hazard ratio = 2.20, 95% confidence interval [1.12-4.33]) and metabolically unhealthy normal weight groups (HR = 2.64, 95% CI [1.34-5.17]). Additionally, the point estimate suggested a 1.97-fold greater risk among the metabolically healthy overweight/obesity group, although this difference was not significant given the wide confidence interval (HR = 1.97, 95% CI [0.80-4.86]).

Conclusion

Our results demonstrated the relationships of metabolic health and weight regarding the risk of Afib in Taiwanese adults. The Afib risk among metabolic and obesity phenotypes is associated with a metabolically unhealthy status. A trend toward a higher Afib risk with obesity among metabolically healthy subjects was observed. However, the result was not robust and it still suggested further study.

Meta-analysis of metabolic syndrome and its individual components with risk of atrial fibrillation in different populations

Background

Recent studies have reported the effects of metabolic syndrome (MetS) and its components on atrial fibrillation (AF), but the results remain controversial. Therefore, we performed a meta-analysis to evaluate the relationship between MetS and AF risk.

Methods

Studies were searched from the Cochrane library, PubMed, and Embase databases through May 2020. Adjusted hazard ratios (HRs) and its corresponding 95% confidence intervals (CIs) were extracted and then pooled by using a random effects model.

Results

A total of 6 observational cohort studies were finally included. In the pooled analysis, MetS was associated with an increased risk of AF (HR 1.57; 95% CI 1.40–1.77; P < 0.01). And the components of MetS including abdominal obesity (HR 1.37; 95% CI 1.36–1.38; P < 0.01), elevated blood pressure (HR 1.56; 95% CI 1.46–1.66; P < 0.01), elevated fasting glucose (HR 1.18; 95% CI 1.15–1.21; P < 0.01) and low high density cholesterol (HDL) (HR 1.18; 95% CI 1.06–1.32; P < 0.01) was also associated with an increased risk of AF, while high triglyceride (HR 0.99; 95% CI 0.87–1.11, P = 0.82) was not.

Conclusions

Our present meta-analysis suggested that MetS, as well as its components including abdominal obesity, elevated blood pressure, elevated fasting glucose and low HDL cholesterol were associated with an increase in the risk of AF.

The role of postprandial very-low-density lipoprotein in the development of atrial remodeling in metabolic syndrome

Background

Negatively charged very-low-density lipoprotein (VLDL-χ) in metabolic syndrome (MetS) patients exerts cytotoxic effects on endothelial cells and atrial myocytes. Atrial cardiomyopathy, manifested by atrial remodeling with a dilated diameter, contributes to atrial fibrillation pathogenesis and predicts atrial fibrillation development. The correlation of VLDL-χ with atrial remodeling is unknown. This study investigated the association between VLDL-χ and remodeling of left atrium.

Methods

Consecutively, 87 MetS and 80 non-MetS individuals between 23 and 74 years old (50.6% men) without overt cardiovascular diseases were included in the prospective cohort study. Blood samples were collected while fasting and postprandially (at 0.5, 1, 2, and 4 h after a unified meal). VLDL was isolated by ultracentrifugation; the percentile concentration of VLDL-χ (%) was determined by ultra-performance liquid chromatography. The correlations of left atrium diameter (LAD) with variables including VLDL-χ, LDL-C, HDL-C, triglycerides, glucose, and blood pressure, were analyzed by multiple linear regression models. A hierarchical linear model was conducted to test the independencies of each variable’s correlation with LAD.

Results

The mean LAD was 3.4 ± 0.5 cm in non-MetS subjects and 3.9 ± 0.5 cm in MetS patients (P < 0.01). None of the fasting lipid profiles were associated with LAD. VLDL-χ, BMI, waist circumference, hip circumference, and blood pressure were positively correlated with LAD (all P < 0.05) after adjustment for age and sex. Significant interactions between VLDL-χ and blood pressure, waist circumference, and hip circumference were observed. When adjusted for obesity- and blood pressure-related variables, 2-h postprandial VLDL-χ (mean 1.30 ± 0.61%) showed a positive correlation with LAD in MetS patients. Each 1% VLDL-χ increase was estimated to increase LAD by 0.23 cm.

Conclusions

Postprandial VLDL-χ is associated with atrial remodeling particularly in the MetS group. VLDL-χ is a novel biomarker and may be a therapeutic target for atrial cardiomyopathy in MetS patients.

Trial registration

ISRCTN 69295295. Retrospectively registered 9 June 2020.

Characterization, Pathogenesis, and Clinical Implications of Inflammation-Related Atrial Myopathy as an Important Cause of Atrial Fibrillation

Historically, atrial fibrillation has been observed in clinical settings of prolonged hemodynamic stress, eg, hypertension and valvular heart disease. However, recently, the most prominent precedents to atrial fibrillation are metabolic diseases that are associated with adipose tissue inflammation (ie, obesity and diabetes mellitus) and systemic inflammatory disorders (ie, rheumatoid arthritis and psoriasis). These patients typically have little evidence of left ventricular hypertrophy or dilatation; instead, imaging reveals abnormalities of the structure or function of the atria, particularly the left atrium, indicative of an atrial myopathy. The left atrium is enlarged, fibrotic and noncompliant, potentially because the predisposing disorder leads to an expansion of epicardial adipose tissue, which transmits proinflammatory mediators to the underlying left atrium. The development of an atrial myopathy not only leads to atrial fibrillation, but also contributes to pulmonary venous hypertension and systemic thromboembolism. These mechanisms explain why disorders of systemic or adipose tissue inflammation are accompanied an increased risk of atrial fibrillation, abnormalities of left atrium geometry and an enhanced risk of stroke. The risk of stroke exceeds that predicted by conventional cardiovascular risk factors or thromboembolism risk scores used to guide the use of anticoagulation, but it is strongly linked to clinical evidence and biomarkers of systemic inflammation.

The Pathogenic Role of Very Low Density Lipoprotein on Atrial Remodeling in the Metabolic Syndrome

Atrial fibrillation (AF) is the most common persistent arrhythmia, and can lead to systemic thromboembolism and heart failure. Aging and metabolic syndrome (MetS) are major risks for AF. One of the most important manifestations of MetS is dyslipidemia, but its correlation with AF is ambiguous in clinical observational studies. Although there is a paradoxical relationship between fasting cholesterol and AF incidence, the benefit from lipid lowering therapy in reduction of AF is significant. Here, we reviewed the health burden from AF and MetS, the association between two disease entities, and the metabolism of triglyceride, which is elevated in MetS. We also reviewed scientific evidence for the mechanistic links between very low density lipoproteins (VLDL), which primarily carry circulatory triglyceride, to atrial cardiomyopathy and development of AF. The effects of VLDL to atria suggesting pathogenic to atrial cardiomyopathy and AF include excess lipid accumulation, direct cytotoxicity, abbreviated action potentials, disturbed calcium regulation, delayed conduction velocities, modulated gap junctions, and sarcomere protein derangements. The electrical remodeling and structural changes in concert promote development of atrial cardiomyopathy in MetS and ultimately lead to vulnerability to AF. As VLDL plays a major role in lipid metabolism after meals (rather than fasting state), further human studies that focus on the effects/correlation of postprandial lipids to atrial remodeling are required to determine whether VLDL-targeted therapy can reduce MetS-related AF. On the basis of our scientific evidence, we propose a pivotal role of VLDL in MetS-related atrial cardiomyopathy and vulnerability to AF.