【关键词】  Arrhythmia

    the Departments of Cardiology (LF) and Endocrinology and Metabolism (PV), Aarhus Sygehus, Aarhus University Hospital, Aarhus, Denmark.

    ABSTRACT

    Background: It is not known whether the consumption of caffeine is associated with excess risk of atrial fibrillation.

    Objective: We evaluated the risk of atrial fibrillation or flutter in association with daily consumption of caffeine from coffee, tea, cola, cocoa, and chocolate.

    Design: We prospectively examined the association between the amount of caffeine consumed per day and the risk of atrial fibrillation or flutter among 47 949 participants ( age: 56 y) in the Danish Diet, Cancer, and Health Study. Subjects were followed in the Danish National Registry of Patients and in the Danish Civil Registration System. The consumption of caffeine was analyzed by quintiles with Cox proportional-hazard models.

    Results: During follow-up (: 5.7 y), atrial fibrillation or flutter developed in 555 subjects (373 men and 182 women). When the lowest quintile of caffeine consumption was used as a reference, the adjusted hazard ratios (95% CIs) in quintiles 2, 3, 4, and 5 were 1.12 (0.87, 1.44), 0.85 (0.65, 1.12), 0.92 (0.71, 1.20), and 0.91 (0.70, 1.19), respectively.

    Conclusion: Consumption of caffeine was not associated with risk of atrial fibrillation or flutter.

    Key Words: Arrhythmia  coffee  epidemiology

    INTRODUCTION

    Caffeine is a methylxanthine that is clinically similar to theophylline, and sympathomimetic effects due to circulating catecholamines cause the cardiac manifestations of caffeine overdose (1, 2). Caffeine toxicity by self-intended poisoning produces tachyarrhythmias such as supraventricular tachycardia, atrial fibrillation, ventricular tachycardia, and ventricular fibrillation (2-5).

    The risk of cardiac arrhythmias associated with customary daily consumption of caffeine from coffee, tea, cola, cocoa, and chocolate does not seem to be increased at the ventricular level (6), but more information is needed about what happens at the supraventricular level (ie, the atrium).

    The literature on caffeine and the risk of supraventricular arrhythmias is sparse. A study in 38 healthy subjects exposed to 1 mg caffeine/kg body wt after a 72-h period of caffeine abstention did not find that excess supraventricular arrhythmias were caused by exposure to caffeine (7). Conversely, atrial tachyarrhythmias including atrial fibrillation and flutter were produced by the intravenous administration of caffeine at a dose ranging from 1 to 5.0 mg caffeine/kg body wt in an experimental study in dogs (8). In the Multifactor Primary Prevention Study begun in Gteborg, Sweden, in 1970, consumption of 14 cups of coffee per day was associated with an age-adjusted odds ratio of atrial fibrillation of 1.24 (95% CI: 1.00, 1.54) during follow-up, whereas drinking >4 cups of coffee was not associated with a risk of atrial fibrillation (9). The purpose of the current study was to examine the assoc