Body mass index and body fat distribution and new-onset atrial fibrillation: Substudy of the European Prospective Investigation into Cancer and Nutrition in Norfolk (EPIC-Norfolk) study

Sex-Specific Cardiometabolic Determinants of Postoperative Atrial Fibrillation After Cardiac Surgery

BACKGROUND

Cardiometabolic diseases increase the risk of postoperative atrial fibrillation (POAF), a complication leading to higher long-term risk of major cardiovascular events (MACE). It remains unknown whether the effect of these risk factors differs according to sex. We sought to evaluate the sex-specific predictors of POAF after coronary artery bypass grafting (CABG).

METHODS

In a prospective registry of patients undergoing isolated CABG, we compared predictors of POAF between sexes with logistic regression models. Because of high prevalence of abdominal obesity in women, > 80% having a waist circumference (WC) ≥ 88 cm, median WC values were used to define abdominal obesity (men ≥ 102 cm, women ≥ 100 cm).

RESULTS

This analysis included 6177 individuals (17% women). Mean age was 65.6 ± 8.9 years. POAF occurred in 32% of men and 28% of women (P < 0.05). Compared with men, women with POAF had similar WC; higher prevalence of hypertension and diabetes; lower high-density lipoprotein (HDL)-cholesterol; and higher glucose, triglyceride, low- density lipoprotein (LDL)-cholesterol, and C-reactive protein levels (all P < 0.05). After adjustment, age and abdominal obesity were associated with POAF in both sexes (P < 0.05). The interaction of WC with sex suggested a worse impact of WC on POAF risk among women (adjusted odds ratio [OR], 1.97; 95% confidence interval [CI], 1.48-2.62 vs in men 1.33; 95% CI, 1.17-1.50; P for interaction = 0.01).

CONCLUSIONS

Abdominal obesity is a major predictor of POAF in both sexes, with higher risk in women. These results emphasize the need for enhanced strategies to manage abdominal obesity and its cardiometabolic consequences in the general population and the potential to develop sex-specific preventive interventions to reduce risk of POAF.

Obesity effect on newly diagnosed and recurrent post-ablation atrial fibrillation: a systematic review and meta-analysis

BACKGROUND AND AIMS

The role of overweight and obesity in the development of atrial fibrillation (AF) is well established; however, the differential effect on the occurrence and recurrence of AF remains uncertain. The aim of this review is to compare the effect of underweight and varying degrees of obesity on onset of AF and in recurrent post-ablation AF, and, when possible, in relation to sex.

METHODS

A systematic literature search was conducted in PubMed, Embase, and Cochrane Library from inception to January 31, 2023. Studies reporting frequency of newly-diagnosed AF and of recurrent post-ablation AF in different BMI categories, were included. 3400 records were screened and 50 met the inclusion criteria. Standardized data search and abstraction were performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) Statement. Data were extracted from the manuscripts and were analyzed using a random effect model. The outcome was the occurrence of AF in population studies and in patients undergoing ablation.

RESULTS

Data from 50 studies were collected, of which 27 for newly-diagnosed AF and 23 for recurrent post-ablation AF, for a total of 15,134,939 patients, of which 15,115,181 in studies on newly-diagnosed AF and 19,758 in studies on recurrent post-ablation AF. Compared to normal weight, the increase in AF was significant (p < 0.01) for overweight, obese, and morbidly obese patients for newly-diagnosed AF, and for obese and morbidly obese patients for recurrent post-ablation AF. Newly-diagnosed AF was more frequent in obese female than obese male patients.

CONCLUSION

The effect of increased BMI was greater on the onset of AF, and obese women were more affected than men.

Association of adiponectin gene expression with atrial fibrillation in a Pakistani populace

Adiponectin, an adipocytokine produced and secreted by adipose tissue, has anti-diabetic, anti-atherogenic, and anti-inflammatory properties. This case-control study was aimed to assess the expression and serum levels of adiponectin in subject suffereing from atrial fibrillation (AF). The study's subjects (n = 690) were enrolled from the Punjab Institute of Cardiology, Lahore and were grouped into control, AF without Metabolic syndrome (MetS), and AF with MetS groups. Along with the collection of demographic data, an analysis of adiponectin and biochemical parameters were performed. A highly significant difference in serum levels of adiponectin was observed among the control, AF without MetS, and AF with MetS groups (61.61 ± 45.30 ng/ml, 37.20 ± 19.46 ng/ml, 63.78 ± 61.69 ng/ml). The expression analysis of adiponectin was decreased (n-fold = ̴ 0.30) in AF without MetS group as compared to control group (n-fold =  ~ 1.16) but increased in AF with MetS group (n-fold = ̴ 6.26). The correlation analysis revealed a highly significant positive relationship between the expression of the adiponectin gene with waist-to-hip ratio (WHR) in AF without MetS group. Whereas, serum adiponectin was negatively related to serum triglycerides (TG) in AF with MetS group. In multiple regression analysis using adiponectin expression as the dependent variable, WHR was a determinant in AF without MetS. Whereas, when serum adiponectin was used as the dependent variable, serum TG was the determinant in group AF with MetS. The present study implicates that decreased expression and serum levels of adiponectin were associated with the development of AF in which WHR and serum TG also contributed towards the onset of atrial fibrillation.

Effect of Prolonged and Substantial Weight Loss on Incident Atrial Fibrillation: A Systematic Review and Meta-Analysis

Background. Overweight and obesity are associated with atrial fibrillation (AF), and bariatric surgery (BS), able to induce sustained and prolonged weight loss, might represent the ideal treatment in the prevention of AF. Previous studies could not definitely establish a role for weight loss and BS in preventing incident AF so far. During the last few years, several studies on the effect of bariatric surgery on cardiovascular diseases have been published, and we performed a systematic review and meta-analysis to evaluate the role of weight loss through BS in the prevention of incident AF in obesity. Methods. This meta-analysis followed the PRISMA guideline. Eligible studies were controlled trials evaluating the appearance of atrial fibrillation in patients undergoing weight loss through BS as compared with patients receiving medical treatment. Quality of studies was assessed according to the Newcastle-Ottawa Quality Assessment Scale, and risk-of-bias was evaluated employing the Egger's test. All analyses were run by a random-effects model according to Hartung and Knapp and sensitivity analyses were performed. Heterogeneity was assessed through Q and I² statistics for each comparison, and potential publication bias was formally investigated. Results. Ten studies were included in the meta-analysis, and the overall result was statistically significant [OR = 0.665 (0.475-0.929), p = 0.017], with significant heterogeneity (Q = 48.98, p < 0.001; I² = 81.6%), but with no publication bias. In sensitivity analyses, the amount of weight loss, percentage of patients with diabetes and value of the Newcastle-Ottawa Quality Assessment Scale, were all associated with significance of effect. Since age was different in one study, a sensitivity analysis was performed by excluding this study; OR was similar [OR = 0.608 (0.454-0.814), p < 0.001]; heterogeneity was reduced but still significant (Q = 35.74, p < 0.001, I² = 77.6%) and again no publication bias was detected. Conclusions. Bariatric surgery as compared to medical treatment is associated with reduced appearance of incident AF.

Nutrition status, obesity and outcomes in patients with atrial fibrillation

INTRODUCTION AND OBJECTIVES

A paradoxical protective effect of obesity has been previously reported in patients with atrial fibrillation (AF). The aim of this study was to determine the impact of nutritional status and body mass index (BMI) on the prognosis of AF patients.

METHODS

We conducted a retrospective population-based cohort study of patients with AF from 2014 to 2017 from a single health area in Spain. The CONUT score was used to assess nutritional status. Cox regression models were used to estimate the association of BMI and CONUT score with mortality. The association with embolism and bleeding was assessed by a competing risk analysis.

RESULTS

Among 14 849 AF patients, overweight and obesity were observed in 42.6% and 46.0%, respectively, while malnutrition was observed in 34.3%. During a mean follow-up of 4.4 years, 3335 patients died, 984 patients had a stroke or systemic embolism, and 1317 had a major bleeding event. On univariate analysis, BMI was inversely associated with mortality, embolism, and bleeding; however, this association was lost after adjustment by age, sex, comorbidities, and CONUT score (HR for composite endpoint, 0.98; 95%CI, 0.95-1.01; P=.719). Neither obesity nor overweight were predictors of mortality, embolism, and bleeding events. In contrast, nutritional status-assessed by the CONUT score-was associated with mortality, embolism and bleeding after multivariate analysis (HR for composite endpoint, 1.15; 95%CI, 1.14-1.17; P<.001).

CONCLUSIONS

BMI was not an independent predictor of events in patients with AF in contrast to nutritional status, which showed a strong association with mortality, embolism, and bleeding. The study was registered at ClinicalTrials.gov (Identifier: NCT04364516).

Longitudinal Anthropometric Measures and Risk of New-Onset Atrial Fibrillation Among Community-Dwelling Men and Women

OBJECTIVE

To assess the sex-specific evolution of various anthropometric measures and the association of their longitudinal trajectories with new-onset atrial fibrillation (AF).

METHODS

Among 5266 men and 7218 women free of AF at baseline from the prospective population-based Rotterdam Study, each anthropometric measure was measured 1 to 5 times from 1989 to 2014. Anthropometric measures were standardized to obtain hazard ratios per 1 SD increase to enable comparison. Joint models were used to assess the longitudinal association between anthropometric measures and incident AF. Use of the joint models is a preferred method for simultaneous analyses of repeated measurements and survival data for conferring less biased estimates.

RESULTS

Mean (SD) age was 63.9 (8.9) years for men and 64.9 (9.8) years for women. Median follow-up time was 10.5 years. Longitudinal evolution of weight, height, waist circumference, hip circumference, and body mass index was associated with an increased risk of new-onset AF in both men and women. In joint models, larger height in men (hazard ratio [95% credible interval] per 1 SD, 1.27 [1.17 to 1.38]) and weight in women (1.24 [1.16 to 1.34]) showed the largest associations with AF. In joint models, waist to hip ratio was significantly associated with incident AF only in women (1.10 [1.03 to 1.18]).

CONCLUSION

Considering the entire longitudinal trajectories in joint models, anthropometric measures were positively associated with an increased risk for new-onset AF among men and women in the general population. Increase in measure of central obesity showed a stronger association with increased risk of AF onset among women compared with men.

Elevated levels of body mass index and waist circumference, but not high variability, are associated with an increased risk of atrial fibrillation

BACKGROUND

Although obesity has been associated with risk of atrial fibrillation (AF), the associations of variability of obesity measures with AF risk are uncertain, and longitudinal studies among Chinese population are still lacking. We aimed to evaluate the impacts of obesity and variability of body mass index (BMI) and waist circumference (WC) on the risk of atrial fibrillation (AF) in a large Chinese cohort study.

METHODS

A total of 44,135 participants of the Kailuan Study who were free of cancer and cardiovascular disease and underwent three consecutive surveys from 2006 to 2010 were followed for incident AF until 2020. Average BMI and WC over time and variability were calculated. Cox proportional hazards regression models were used to assess hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations of obesity and variability in BMI and WC with AF risk.

RESULTS

During a mean follow-up of 9.68 years, there were 410 cases of incident AF. In multivariable-adjusted models, compared with normal BMI/WC, individuals with general obesity and abdominal obesity had increased risk of AF, with corresponding HRs of 1.73 (95% CI: 1.31-2.30) and 1.38 (95% CI: 1.11-1.60), respectively. The short-term elevation in AF risk persisted for the obese even after adjustment for updated biologic intermediaries and weight. Variability in BMI and WC were not associated with the risk of AF. The restricted cubic spline models indicated significant linear relationships between levels of WC and BMI and risk of AF.

CONCLUSIONS

Elevated levels of BMI and WC were associated with an increased risk of AF, whereas variability in BMI and WC were not. Therefore, achieving optimal levels of BMI and WC could be valuable in AF prevention.

Increasing Adiposity Is Associated With QTc Interval Prolongation and Increased Ventricular Arrhythmic Risk in the Context of Metabolic Dysfunction: Results From the UK Biobank

Background

Small-scale studies have linked obesity (Ob) and metabolic ill-health with proarrhythmic repolarisation abnormalities. Whether these are observed at a population scale, modulated by individuals' genetics, and confer higher risks of ventricular arrhythmias (VA) are not known.

Methods and Results

Firstly, using the UK Biobank, the association between adiposity and QTc interval was assessed in participants with a resting 12-lead ECG (n = 23,683), and a polygenic risk score (PRS) was developed to investigate any modulatory effect of genetics. Participants were also categorised into four phenotypes according to the presence (+) or absence (-) of Ob, and if they were metabolically unhealthy (MU+) or not (MU-). QTc was positively associated with body mass index (BMI), body fat (BF), waist:hip ratio (WHR), and hip and waist girths. Individuals' genetics had no significant modulatory effect on QTc-prolonging effects of increasing adiposity. QTc interval was comparably longer in those with metabolic perturbation without obesity (Ob-MU+) and obesity alone (Ob+MU-) compared with individuals with neither (Ob-MU-), and their co-existence (Ob+MU+) had an additive effect on QTc interval. Secondly, for 502,536 participants in the UK Biobank, odds ratios (ORs) for VA were computed for the four clinical phenotypes above using their past medical records. Referenced to Ob-MU-, ORs for VA in Ob-MU+ men and women were 5.96 (95% CI: 4.70-7.55) and 5.10 (95% CI: 3.34-7.80), respectively. ORs for Ob+MU+ were 6.99 (95% CI: 5.72-8.54) and 3.56 (95% CI: 2.66-4.77) in men and women, respectively.

Conclusion

Adiposity and metabolic perturbation increase QTc to a similar degree, and their co-existence exerts an additive effect. These effects are not modulated by individuals' genetics. Metabolic ill-health is associated with a higher OR for VA than obesity.

Neck Circumference and Risk of Incident Atrial Fibrillation in the Framingham Heart Study

Background

Increased neck circumference, a proxy for upper‐body subcutaneous fat, is associated with cardiovascular risk and metabolic risk factors, accounting for body mass index (BMI) and waist circumference. The association between neck circumference and incident atrial fibrillation (AF) is unclear. The aim of current study was to evaluate the association between neck circumference and incident AF.

Methods and Results

We selected participants from the Framingham Heart Study aged ≥55 years without diagnosed AF and with available neck circumference, BMI, and waist circumference measurements. We defined high neck circumference as ≥14 inches in women and ≥17 inches in men on the basis of the Contal and O’Quigley changepoint method. We used Fine‐Gray models to estimate subdistribution hazards ratios (sHRs) for the association between neck circumference and incident AF accounting for the competing risk of death. We adjusted models for clinical risk factors. We then additionally adjusted separately for BMI, waist circumference, and height/weight. The study sample included 4093 participants (mean age 64±7 years, 55% female). During 11.2±5.7 mean years of follow‐up, incident AF occurred in 571 participants. High neck circumference was associated with incident AF (sHR for high versus low: 1.58; 95% CI, 1.32–1.90, P<0.0001). The association remained significant after adjustment for BMI (sHR, 1.51; 95% CI, 1.21–1.89; P=0.0003), waist circumference (sHR, 1.47; 95% CI, 1.18–1.83; P<0.0001), and height/weight (sHR, 1.37; 95% CI, 1.09–1.72; P=0.007).

Conclusions

High neck circumference was associated with incident AF adjusting for traditional adiposity measures such as BMI and waist circumference.

Effectiveness and safety of rivaroxaban versus warfarin among nonvalvular atrial fibrillation patients with obesity and diabetes

AIMS

To compare clinical outcomes of rivaroxaban and warfarin in patients with nonvalvular atrial fibrillation (NVAF) and concurrent obesity and diabetes.

METHODS

Patients aged ≥18 years were identified from a healthcare claims database with the following criteria: newly initiating rivaroxaban or warfarin, ≥1 medical claim with a diagnosis of AF, obesity determined by validated machine learning algorithm, and ≥1 claim with a diagnosis of diabetes or for antidiabetic medication. Treatment cohorts were matched using propensity scores and were compared for stroke/systemic embolism (SE) and major bleeding using Cox proportional hazards models.

RESULTS

A total of 9999 matched pairs of NVAF patients with obesity and diabetes who initiated treatment with rivaroxaban or warfarin were included. The composite risk of stroke/SE was significantly lower in the rivaroxaban cohort compared with the warfarin cohort (HR 0.82; 95% CI 0.74-0.90). Risks of ischemic and hemorrhagic strokes were also significantly reduced with rivaroxaban versus warfarin, but not SE. Major bleeding risk was similar between treatment cohorts (HR 0.92; 95% CI 0.78-1.09).

CONCLUSIONS

In NVAF patients with comorbidities of obesity and diabetes, rivaroxaban was associated with lower risks of stroke/SE and similar risk of major bleeding versus warfarin.

Effect modification of general and central obesity by sex and age on cardiovascular outcomes: Targeted maximum likelihood estimation in the atherosclerosis risk in communities study

BACKGROUND AND AIMS

To elucidate the effect modification of general and central obesity by sex and age on the risk of cardiovascular events.

METHODS

The analysis included 14,983 males and females aged 45-75 years from the Atherosclerosis Risk in Communities study. Obesity was defined with body mass index (BMI), waist-to-hip ratio (WHR) and body shape index (BSI) which categorized the participants as obese and non-obese. Targeted maximum likelihood estimation was used to estimate the risk ratio (RR) with the tmle package in R software.

RESULTS

After adjustment, the strongest effect of BMI on CHD was in females (RR (95%CI): 1.26 (1.11, 1.42)) and in age>54 (RR (95%CI): 1.16 (1.06, 1.27)) and for HF it was in age>54 (RR (95%CI): 1.18 (1.10, 1.26)) and in females (RR (95%CI): 1.17 (1.08, 1.28)). Regarding central obesity, WHR (RR (95%CI): 1.19 (1.05, 1.34)) had the strongest effects on CHD for males and BSI (RR (95%CI): 1.140 (1.02, 1.26)) for age ≤ 54, and for HF the WHR (RR (95%CI): 1.22 (1.10, 1.36)) and BSI (RR (95%CI): 1.18 (1.07, 1.30)) had the strongest effects for age≤54, respectively.

CONCLUSION

Among males and age≤54, WHR index was associated with a higher risk of CHD and HF while BMI was so for females and age>54.

Race, Body Mass Index, and the Risk of Atrial Fibrillation: The Multi-Ethnic Study of Atherosclerosis

Background

Higher body mass index (BMI) is associated with increased risk of incident atrial fibrillation (AF), but it is not known whether this relationship varies by race/ethnicity.

Methods and Results

Eligible participants (6739) from MESA (Multi‐Ethnic Study of Atherosclerosis) were surveilled for incident AF using MESA hospital surveillance, scheduled MESA study ECG, and Medicare claims data. After a median 13.8 years of follow‐up, 970 participants (14.4%) had incident AF. With BMI modeled categorically in a Cox proportional hazards model, only those with grade II and grade III obesity had increased risks of AF (hazard ratio [HR], 1.50; 95% CI, 1.14–1.98, P=0.004 for grade II obesity and HR, 2.13; 95% CI, 1.48–3.05, P<0.0001 for grade III obesity). The relationship between BMI and AF risk was J‐shaped. However, the risk of AF as a function of BMI varied substantially by race/ethnicity (P value for interaction=0.02), with Chinese‐American participants having a much higher risk of AF with higher BMI and Black participants having minimal increased risk of AF with higher BMI.

Conclusions

Obesity is associated with an increased risk of incident AF, but the relationship between BMI and the risk of AF is J‐shaped and this relationship differs by race/ethnicity, such that Chinese‐American participants have a more pronounced increased risk of AF with higher BMI, while Black participants have minimal increased risk. Further exploration of the differential effects of BMI by race/ethnicity on cardiovascular outcomes is needed.