Association between metabolically healthy obesity and risk of atrial fibrillation: taking physical activity into consideration

Association between metabolically healthy obesity and atrial fibrillation: A systematic review and meta-analysis of longitudinal studies

INTRODUCTION

Obesity is not a single diagnosis, and the association of 'metabolically unhealthy' obesity with cardiovascular disease is well-described. However, the relationship between metabolically healthy obesity (MHO) and atrial fibrillation (AF) is still debated.

OBJECTIVE

Our objective is to investigate the association between MHO and the risk of AF.

METHODS

A comprehensive search of databases, including PubMed, EMBASE, Web of Science, and the Cochrane Library regarding longitudinal studies of MHO and risk of AF was performed. Random effects were used to pool the effect estimates.

RESULTS

Nine cohort studies comprising 4,250,557 participants were included. The pooled results revealed that individuals with MHO were associated with a greater incidence of AF than those with a metabolically healthy normal weight (HR: 1.34, 95 % CI: 1.26 to 1.42) with moderate certainty according to the Grading of Recommendations Assessment, Development, and Evaluation assessment. Individuals with MHO were associated with a lower risk of AF compared with participants with metabolically unhealthy obesity (RR: 0.48, 95 % CI: 0.36 to 0.64). Individuals with MHO were not significantly associated with the risk of AF as compared to metabolically unhealthy normal weight (HR: 1.04, 95 % CI: 0.89 to 1.22).

CONCLUSION

MHO is associated with a greater incidence of AF, highlighting the importance of weight reduction in individuals without metabolic disorders in reducing the risk of AF.

REGISTRATION

PROSPERO - registration number CRD42023432195.

Controversies and challenges of anticoagulation therapy in obesity

INTRODUCTION

The relationship between anticoagulation efficacy and safety in obesity is complex and can vary between degrees of obesity and anticoagulant choice. Indeed, patients at extremes of body weight were under-represented in randomized trials. Additionally, the possibility of an 'obesity paradox' has been raised in atrial fibrillation, describing decreased thromboembolic risk in obese patients.

AREAS COVERED

We explore the current literature on anticoagulation in obesity, specifically with regard to efficacy in atrial fibrillation, efficacy in venous thromboembolism, and bleeding risk. Pharmacodynamic and pharmacokinetic considerations are also discussed.

EXPERT OPINION

As a class, direct oral anticoagulants are comparable to vitamin-K antagonists in preventing and treating thromboembolism in overweight and obese patients, whilst not increasing bleeding risk.

Effect of physical exercise on metabolism in patients with atrial fibrillation

Atrial fibrillation (AF), the most prevalent cardiac arrhythmia, is closely linked to metabolic dysfunctions, including obesity, diabetes, and dyslipidemia. These lead to pathological changes in myocardial metabolism and mitochondrial energy metabolism, thereby aggravating AF's incidence and severity. This review introduces the role of metabolic dysfunctions in exacerbating AF, assesses the therapeutic potential of physical exercise and investigates it as a non-pharmacological intervention to alleviate these metabolic disturbances. Evidence suggests that regular physical activity not only enhances metabolic profiles but also reduces the frequency of AF episodes and improves overall cardiovascular health. At the same time, the review emphasizes the need for individualized exercise regimens, individualized to the metabolic and cardiac conditions of each patient to optimize benefits and minimize risks. Additionally, it calls for more basic studies and large-scale clinical trials to establish and refine evidence-based exercise guidelines specific to AF management.

Risk of Adverse Events in Anticoagulated Patients With Atrial Fibrillation and Nonalcoholic Fatty Liver Disease

BACKGROUND

The clinical impact of nonalcoholic fatty liver disease (NAFLD) in patients with atrial fibrillation (AF) is still controversial.

AIM

To evaluate the 1-year risk of all-cause death, thromboembolic events, and bleeding in patients with AF-NAFLD.

METHODS

Retrospective study with a health research network (TriNetX). Patients with AF on oral anticoagulation (OAC) were categorized according to the presence of NAFLD into 2 groups. The primary outcomes were the 1-year risks of (1) a composite cardiovascular outcome (all-cause death, myocardial infarction, stroke, cardiac arrest, and pulmonary embolism) and (2) a composite hemorrhagic outcome (intracranial hemorrhage and gastrointestinal bleeding). Cox regression analysis before and after propensity score matching was used to estimate hazard ratio (HR) and 95% 95% CI,. Sensitivity analyses investigated the risk associated with cirrhosis, thrombocytopenia, and type of OAC (warfarin vs non-vitamin K antagonist oral anticoagulants (NOACs).

RESULTS

We identified 22 636 patients with AF-NAFLD (69 ± 12 years, 46.7% females) and 391 014 patients with AF and without liver disease (72 ± 12 years, 42.7% females). NAFLD was associated with a higher risk of composite cardiovascular (HR, 1.54; 95% CI, 1.47-1.61) and hemorrhagic (HR, 1.56; 95% CI, 1.42-1.72) outcomes. This was consistent also for all the single outcomes. Cirrhotic and thrombocytopenic patients with AF-NAFLD showed the highest risks. Compared to patients with AF-NAFLD on NOACs, those on warfarin were associated with a higher risk of cardiovascular and hemorrhagic outcomes.

CONCLUSION

In patients with AF, NAFLD is associated with a higher 1-year risk of adverse events, with the risk of adverse events progressively increasing from noncirrhotic to cirrhotic and from nonthrombocytopenic to thrombocytopenic patients. NOACs were associated with a better effectiveness and safety profile compared to warfarin.

Exploring the Causal Effects of Physical Activity, Sedentary Behaviour, and Diet on Atrial Fibrillation and Heart Failure: A Multivariable Mendelian Randomisation Analysis

AIMS

This study aimed to investigate the causal effects of physical activity, sedentary behaviour, and diet on atrial fibrillation (AF) and heart failure (HF) using multivariate Mendelian randomization (MR) analysis and genetic variants as instrumental variables.

METHODS

The study employed multivariate MR analysis with physical activity, sedentary behaviour, and diet as exposures and AF and HF as outcomes. Data were obtained from the UK Biobank (over 500,000 participants) and the FinnGen project (218,792 participants of European ancestry). Genetic variants associated with physical activity, diet, and sedentary behaviour were used as instrumental variables. The main analysis methods included the inverse variance weighted (IVW) method, MR-Egger, and weighted median methods. Heterogeneity was assessed using Cochran's Q test.

RESULTS

The analyses generally did not demonstrate significant causal relationships between physical activity or sedentary behaviour and AF. Diet showed a potential protective effect on AF in some analyses but was not consistently significant across methods. For HF, physical activity and sedentary behaviour did not show significant causal relationships. Diet showed a significant protective effect against HF in the IVW method but was not consistent across all methods.

CONCLUSIONS

This study suggests that while there may be some protective effects of these lifestyle factors on cardiovascular disease, most analyses did not show significant causality, and results were inconsistent. Further research is needed to validate these findings.

Elevated remnant cholesterol was associated with the increased metabolically unhealthy obesity risk in Chinese youth

BACKGROUND AND OBJECTIVES

Metabolically unhealthy obesity is characterized by the presence of cardiovascular metabolic risks such as hypertension, dyslipidemia, and hyperglycemia. Research has shown a correlation between remnant cholesterol (RC) concentrations and abdominal obesity in children. However, the effect of RC concentration on metabolically unhealthy obesity remains unclear.

METHODS AND STUDY DESIGN

This study included 3114 Chinese adolescents who received health check-ups. We used logistic regression models and receiver operating characteristic analysis to evaluate the correlation between RC concentration and metabolically unhealthy obesity in a cross-sectional design.

RESULTS

After controlling for possible confounding variables, we found that individuals in the top and fourth quintiles of RC concentrations had a significantly higher likelihood of developing metabolically unhealthy obesity compared to those in the bottom quintile (ORs, 4.810 and 1.836; 95% CIs, 3.209-7.212 and 1.167-2.890, respectively). The risk of metabolically unhealthy obesity tended to increase with RC concentration (ptrend<0.001). In addition, boys showed positive associations between RC concentration and both BMI (r = 0.305, p<0.001) and waist circumference (r = 0.306, p<0.001). According to the analysis, the predictive accuracy of metabolically unhealthy obesity was 0.736 (95% CI, 0.690-0.781) for boys and 0.630 (95% CI, 0.573-0.687) for girls. The ideal prediction threshold was 0.66 for boys and 0.59 for girls.

CONCLUSIONS

Our findings indicate that elevated RC concen-tration is linked to a higher likelihood of developing metabolically unhealthy obesity in young individuals, regardless of other known risk factors.

Associations between life's essential 8 and metabolic health among us adults: insights of NHANES from 2005 to 2018

BACKGROUND

Metabolic unhealth (MUH) is closely associated with cardiovascular disease (CVD). Life's Essential 8 (LE8), a recently updated cardiovascular health (CVH) assessment, has some overlapping indicators with MUH but is more comprehensive and complicated than MUH. Given the close relationship between them, it is important to compare these two measurements.

METHODS

This population-based cross-sectional survey included 20- to 80-year-old individuals from 7 National Health and Nutrition Examination Survey (NHANES) cycles between 2005 and 2018. Based on the parameters provided by the American Heart Association, the LE8 score (which ranges from 0 to 100) was used to classify CVH into three categories: low (0-49), moderate (50-79), and high (80-100). The MUH status was evaluated by blood glucose, blood pressure, and blood lipids. The associations were assessed by multivariable regression analysis, subgroup analysis, restricted cubic spline models, and sensitivity analysis.

RESULTS

A total of 22,582 participants were enrolled (median of age was 45 years old), among them, 11,127 were female (weighted percentage, 49%) and 16,595 were classified as MUH (weighted percentage, 73.5%). The weighted median LE8 scores of metabolic health (MH) and MUH individuals are 73.75 and 59.38, respectively. Higher LE8 scores were linked to lower risks of MUH (odds ratio [OR] for every 10 scores increase, 0.53; 95% CI 0.51-0.55), and a nonlinear dose-response relationship was seen after the adjustment of potential confounders. This negative correlation between LE8 scores, and MUH was strengthened among elderly population.

CONCLUSIONS

Higher LE8 and its subscales scores were inversely and nonlinearly linked with the lower presence of MUH. MUH is consistent with LE8 scores, which can be considered as an alternative indicator when it is difficult to collect the information of health behaviors.

Trends and characteristics of the metabolically healthy obese phenotype in an Arab population

The metabolically healthy obesity (MHO) phenotype represents a complex and distinctive trait, the trends and characteristics of which remain unknown in the Saudi Arabian adult population. The present study aims to fill that gap. A combined total of 10,220 Saudi adults from 2 independent cohorts [2008-2019, N = 7,896 (2,903 males and 4,993 females), and 2021-2023, N = 2,324 (830 males and 1,494 females)] aged 19-70 years old was screened, of whom 9,631 (3,428 males and 6,203 females) were included. Anthropometric data were measured, and fasting blood samples were collected to assess glucose, lipids, adipocytokines and inflammatory markers using routine methods and commercially available assays. Obesity was defined as a body mass index (BMI) ≥30 kg/m2. Screening for MHO was done using the empiric definition proposed by Zembic and colleagues and the by the National Cholesterol Education Program's Adult Treatment Panel III (NCEP ATPIII). Of the 3,949 (41.0%) participants with obesity, 33.4% (95% confidence interval, CI, 32-35) were considered MHO using the empiric definition, and 32.8% (95% CI, 31-34) using NCEP-ATPIII. The overall age and gender adjusted prevalence of MHO in the Saudi adult population was 31.6% (95% CI, 30-33) and 30.1% (29-31) by the two definitions, respectively. Females had a higher age-adjusted prevalence of MHO than males (OR = 1.22, 95% CI 1.1-1.4, p = 0.009) as per the ATPIII criteria. MHO prevalence substantially increased over time from 2008 to 2023 (p < 0.001) for both definitions. Circulating leptin levels and insulin resistance were significantly higher in the MUO group than the MHO group independent of the definition used, suggesting the presence of a more severe form of leptin resistance in the MUO group which may explain the worse cardiometabolic profile as compared to the MHO group. In summary, the study highlights the first time the characteristics and trends of the MHO phenotype among Saudi Arabian adults. The pluripotent effects of leptin and its resistance may be central to MHO's progression, or lack thereof, to the MUO phenotype, and this needs further investigation.

Racial and Gender Differences in Cardiorespiratory Fitness and Atrial Fibrillation

The expanding field of cardiorespiratory fitness (CRF) in individuals with and without atrial fibrillation (AF) presents a complex landscape, demanding careful interpretation of the existing research. AF, characterized by significant mortality and morbidity, prompts the exploration of strategies to mitigate its impact. Increasing physical activity (PA) levels emerges as a promising avenue to address AF risk factors, such as obesity, hypertension, and diabetes mellitus, through mechanisms of reduced vasoconstriction, endothelin-1 modulation, and improved insulin sensitivity. However, caution is warranted, as recent investigations suggest a heightened incidence of AF, particularly in athletes engaged in high-intensity exercise, due to the formation of ectopic foci and changes in cardiac anatomy. Accordingly, patients should adhere to guideline-recommended amounts of low-to-moderate PA to balance benefits and minimize adverse effects. When looking closer at the current evidence, gender-specific differences have been observed and challenged conventional understanding, with women demonstrating decreased AF risk even at extreme exercise levels. This phenomenon may be rooted in divergent hemodynamic and structural responses to exercise between men and women. Existing research is predominantly observational and limited to racially homogenous populations, which underscores the need for comprehensive studies encompassing diverse, non-White ethnic groups in athlete and non-athlete populations. These individuals exhibit a disproportionately high burden of AF risk factors that could be addressed through improved CRF. Despite the limitations, randomized control trials offer promising evidence for the efficacy of CRF interventions in patients with preexisting AF, showcasing improvements in clinically significant AF outcomes and patient quality of life. The potential of CRF as a countermeasure to the consequences of AF remains an area of great promise, urging future research to delve deeper to explore its role within specific racial and gender contexts. This comprehensive understanding will contribute to the development of tailored strategies for optimizing cardiovascular health and AF prevention in all those who are affected.

Analysis Using Various Models on the Effect of Metabolic Surgery on Cardiovascular Disease Risk in the Chinese Population with Obesity

Background

Some research have indicated that Bariatric and metabolic surgery (BMS) can reduce the risk of cardiovascular disease (CVD) among individuals with obesity. However, there are few reports available that focuses on assessing effect of BMS on the risk of CVD in Chinese population using multiple models.

Objective

This research aims to assess the function of BMS on the risk of CVD in Chinese patients with obesity using multiple CVD risk models.

Methods

We performed a retrospective analysis of the basic data and glycolipid metabolism data preoperatively and postoperatively from patients with obesity at our hospital. Subgroup analysis was carried out according to different surgical procedures. Then, the function of BMS on the risk of CVD in the Chinese population was assessed using four models, including: China-PAR risk model, Framingham risk score (FRS), World Health Organization (WHO) risk model, and Globorisk model.

Results

We enrolled 64 patients, 24 (37.5%) of whom underwent laparoscopic sleeve gastrectomy (LSG) while 40 (62.5%) underwent Roux-en-Y gastric bypass (RYGB). The 10-year CVD risk for patients calculated using the China-PAR risk model decreased from 6.3% preoperatively to 2.0% at 1 year postoperatively and was statistically significantly different. Similarly, the 10-year CVD risk of patients calculated using the FRS, WHO, Global risk model decreased significantly at 1 year postoperatively compared to preoperatively. When the FRS risk model was used to calculate the patients' 30-year postoperative CVD risk, there was a significant decrease at 1 year after surgery compared to the preoperative period. When employing various models to evaluate the 10-year CVD risk for LSG and RYGB, no statistically significant difference was found in the 1-year postoperative RRR between the procedures.

Conclusion

The CVD risk after BMS was significantly reduced compared to preoperatively. In terms of improving cardiovascular risk, SG and RYGB appear to be equally effective.

Exploring metabolically healthy obesity: prevalence, characteristics, and cardiovascular risk in the Iranian population based on the STEPS 2021

Background

Regarding the rapidly increasing prevalence of obesity throughout the globe, it remains a serious public health concern. A subgroup of obesity that does not meet metabolic syndrome criteria is called metabolically healthy obesity (MHO). However, whether the MHO phenotype increases cardiovascular disease (CVD) risk is controversial. This study aimed to evaluate the prevalence of MHO and its 10-year CVD risk in Iranian populations.

Methods

Based on the STEPS 2021 project in Iran, we collected data on 18119 Iranians 25 years and older from all 31 provinces after applying many statistical factors. Using the Framingham score, we evaluated the 10-year cardiovascular risk associated with the various MHO definition criteria for Iranian populations.

Results

The prevalence of MHO was 6.42% (5.93-6.91) at the national level according to the AHA-NHLBI definition, and 23.29% of obese women and 24.55% of obese men were classified as MHOs. Moreover, the MHO group was younger than the metabolically unhealthy obesity (MUO) group based on all definitions (p < 0.001). The odds ratio of MUO individuals being classified as high-risk individuals by the Framingham criteria for CVD was significantly higher than that of MHO individuals by all definitions, with a crude odds ratio of 3.55:1 based on AHA-NHLBI definition.

Conclusion

This study reveals a significant prevalence of MHO in the Iranian population, with approximately 25% of obese individuals classified as MHO. While MHO is associated with a lower risk of cardiovascular disease compared to MUO, MHO carries the potential for transitioning to an unhealthy state.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01364-5.

Relationship between metabolic status, physical activity and cardiovascular disease in participants with obesity

OBJECTIVE

We aimed to investigate the independent and joint associations between metabolic status, PA (physical activity) and risk of CVD (cardiovascular disease) in participants with obesity.

METHODS

We included 109,301 adults with obesity free of baseline CVD enrolled from 2006 to 2010 in the UK Biobank cohort (aged 56 ± 7.9 years). Based on metabolic status, obesity was grouped into metabolically healthy obesity (MHO; free of hypertension, hypercholesterolemia and diabetes; n = 26,989; BMI 33 ± 3.3 kg/m2) and metabolically unhealthy obesity (MUO; n = 82,312; BMI 34 ± 4.0 kg/m2). PA was categorized into four groups according to moderate-to-vigorous PA (MVPA): none, low, medium, and high. Multivariable Cox regression models were used for the main analyses adjusting for sociodemographic factors, lifestyles and comorbidities.

RESULTS

There were 8,059 CVD events during a median follow-up of 8.1 years. MHO was associated with a 42% reduced risk of CVD compared with MUO (HR = 0.58, 95% CI: 0.53-0.63). A significant interaction effect between PA and metabolic status on CVD risk was found. Among MUO participants, individuals with PA had significantly decreased CVD risk when compared with no MVPA (HR = 0.87, 95% CI: 0.81-0.94 for low PA; HR = 0.85, 95% CI: 0.78-0.93 for medium PA; and HR = 0.86, 95% CI: 0.80-0.92 for high PA). The lowest CVD risk was observed in MHO & medium PA group when compared with MUO & no MVPA (HR = 0.45, 95% CI: 0.37-0.56).

CONCLUSIONS

Both MHO and any MVPA were associated with reduced risk of CVD in adults with obesity, while PA could modify the relationship between metabolic status and CVD risk.

Obesity phenotypes and cardiovascular risk: From pathophysiology to clinical management

Obesity epidemic reached the dimensions of a real global health crisis with more than one billion people worldwide living with obesity. Multiple obesity-related mechanisms cause structural, functional, humoral, and hemodynamic alterations with cardiovascular (CV) deleterious effects. A correct assessment of the cardiovascular risk in people with obesity is critical for reducing mortality and preserving quality of life. The correct identification of the obesity status remains difficult as recent evidence suggest that different phenotypes of obesity exist, each one associated with different degrees of CV risk. Diagnosis of obesity cannot depend only on anthropometric parameters but should include a precise assessment of the metabolic status. Recently, the World Heart Federation and World Obesity Federation provided an action plan for management of obesity-related CV risk and mortality, stressing for the instauration of comprehensive structured programs encompassing multidisciplinary teams. In this review we aim at providing an updated summary regarding the different obesity phenotypes, their specific effects on CV risk and differences in clinical management.

Relationship between obesity severity, metabolic status and cardiovascular disease in obese adults

BACKGROUND

Evidence about the associations between obesity severity, metabolic status and risk of incident cardiovascular disease (CVD) in adults with obesity remains limited.

METHODS

The study included 109,301 adults with obesity free of prior CVD based on the UK Biobank cohort. Metabolic status was categorized into metabolically healthy obesity (MHO; free of hypertension, hypercholesterolemia and diabetes) and metabolically unhealthy obesity (MUO). Obesity severity was classified into three levels: class I (body mass index of 30.0-34.9 kg/m² ), II (35.0-39.9) and III (≥40.0). Cox proportional hazards models were used for analyses.

RESULTS

There were 8059 incident CVD events during a median follow-up of 8.1 years. MUO was significantly associated with a 74% increased CVD risk compared with MHO (HR = 1.74, 95% CI: 1.62-1.83). There was a significant interaction between obesity severity and metabolic status on an additive scale regarding CVD risk. When taking class I obesity as reference, class II was nonsignificantly associated with an increased risk of CVD in the MHO group (HR = 1.07, 95% CI: 0.90-1.27), while class III was significantly related to increased risks of CVD (HR = 1.48, 95% CI: 1.12-1.96). In the MUO group, both classes II and III were significantly related to increased risks of CVD. Significant subgroup effects of age (p = .009) and sex (p = .047) were observed among participants with MUO but not in the MHO group.

CONCLUSIONS

Both elevated obesity severity and MUO were significantly associated with increased risks of CVD in adults with obesity, while metabolic status could modify the relationship between obesity severity and CVD risk. More research is needed to further clarify the relationship.