Habitual drinking of coffee may reduce risk of arrhythmia: Study

There is a common myth that caffeine in coffee increases the risk of cardiac arrhythmias. However, there is not enough evidence to prove this notion.

A study was conducted by a group of researchers from the University of California, San Francisco, USA to assess the association between the consumption of common caffeinated products and the risk of arrhythmias.

The researchers conducted a prospective cohort study and evaluated longitudinal data from the UK Biobank between the period January 1, 2006, to December 31, 2018. A total of 386,258 individuals were selected for analyses, after applying the exclusion criteria.

The main outcome of the study was any cardiac arrhythmia, including atrial fibrillation or flutter, supraventricular tachycardia, ventricular tachycardia, premature atrial complexes, and premature ventricular complexes.

The findings of the study are as follows:

Ø A total of 16,979 participants developed an incident arrhythmia during a mean (SD) follow-up of 4.5 (3.1) years,

Ø Each additional cup of habitual coffee consumed was associated with a 3% lower risk of incident arrhythmia, after adjustment for demographic characteristics, comorbid conditions, and lifestyle habits.

Ø In analyses of each arrhythmia alone, statistically significant associations exhibiting a similar the magnitude was observed for atrial fibrillation and/or flutter and supraventricular tachycardia.

Ø Two distinct interaction analyses, one using a caffeine metabolism-related polygenic score of 7 genetic polymorphisms and another restricted to CYP1A2 rs762551 alone did not reveal any evidence of effect modification.

Ø A mendelian randomization study that used these same genetic variants revealed no significant association between underlying propensities to differing caffeine metabolism and the risk of incident arrhythmia.

Thus, the researchers concluded that a greater quantity of habitual coffee consumption was indirectly related to a lower risk of arrhythmia, with no evidence that genetically mediated caffeine metabolism affected that association. And that Mendelian randomization failed to prove that caffeine consumption was associated with arrhythmias.

Reference:

Coffee Consumption and Incident Tachyarrhythmias: Reported Behavior, Mendelian Randomization, and Their Interactions by Kim E et. al published in the JAMA Intern Med

doi:10.1001/jamainternmed.2021.3616