Association Between Non-alcoholic Fatty Liver Disease and Risk of New-onset Atrial Fibrillation in Healthy Adults

Jae-Hyung Roh; Jae-Hwan Lee; Hanbyul Lee; Yong-Hoon Yoon; Minsu Kim; Yong-Giun Kim; Gyung-Min Park; Jae-Hyeong Park; In-Whan Seong

Disclosures

Liver International. 2020;40(2):338-346. 

In This Article

Abstract and Introduction

Abstract

Background & Aims: Previous studies demonstrated conflicting results regarding the association between non-alcoholic fatty liver disease (NAFLD) and atrial fibrillation (AF). The statistical power was not sufficient because of modest sample sizes of these studies. We analysed a large population-based cohort to evaluate the association between NAFLD and AF.

Methods: We evaluated 334 280 healthy individuals without comorbidities who underwent National Health check-ups in South Korea from 2009 to 2014. NAFLD was defined by a surrogate marker, the fatty liver index (FLI). The association between FLI and AF incidence was analysed using multivariate Cox proportional hazards regression models.

Results: During a median follow-up of 5.3 years, 1415 subjects (0.4%) were newly diagnosed with AF. Subjects were categorized into quartile groups according to FLI (range: Q1, 0–4.9; Q2, 5.0–12.5; Q3, 12.6–31.0; Q4, >31.0). The cumulative incidence of AF was significantly higher in subjects with higher FLIs than in those with lower FLIs (Q1, 167 [0.2%]; Q2, 281 [0.3%]; Q3, 470 [0.6%]; Q4, 497 [0.6%]; P < .001). Adjusted hazard ratios (HRs) indicated that a higher FLI was independently associated with an increased risk for AF (HR between Q4 and Q1, 1.35; 95% confidence interval [CI], 1.11–1.63; P = .002). After further adjustment for the interim events (diabetes, hypertension, heart failure and myocardial infarction), this association remained statistically significant (HR between Q4 and Q1, 1.55; 95% CI, 1.19–2.03; P = .001).

Conclusions: NAFLD, assessed by FLI, was independently associated with increased risk for AF in healthy Korean population. Moreover, NAFLD itself predisposes to AF independently of the interim events.

Introduction

Non-alcoholic fatty liver disease (NAFLD) has reached epidemic proportions, reflecting the current prevalence of obesity, insulin resistance and type 2 diabetes mellitus, and metabolic syndrome. Approximately 15%-30% of adults in the general population are affected by NAFLD, with a prevalence increasing to 60%-90% among obese or diabetic individuals.[1] NAFLD has been increasingly recognized as a multisystem disease with a substantial risk for cardiovascular disease in affected patients independent of traditional risk factors. Furthermore, its multisystemic nature raises suspicion of an association with non-ischaemia-related cardiac diseases, especially those involving cardiac electrical system. Atrial fibrillation (AF) is the most commonly diagnosed cardiac arrhythmia in clinical practice. It affects >2 million people in the USA, and this figure is projected to double by 2050.[2] Individuals with AF are at a substantially increased risk of stroke and overall mortality. In spite of the clinical burden and impact of AF, a limited number of longitudinal studies evaluated the association between NAFLD and AF.[3–8] Moreover, the conflicting results and modest sample sizes warrant a larger cohort study with sufficient follow-up duration. We therefore analysed a large, comprehensive cohort consisting of a healthy Korean adult population without the traditional risk factors and co-morbidities in an attempt to identify the direct correlation between NAFLD and AF.

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