Acute electrophysiological effects of energy drink, energy gum and coffee: a double-blind randomized placebo-controlled crossover study

Abstract

Abstract Background Energy drink consumption is highly prevalent in young adults, especially in males, and has been associated with adverse cardiovascular events, including QT prolongation and atherothrombosis. A proposed mechanism underlying these adverse cardiovascular effects is caffeine, but this has not been systematically evaluated. Therefore, the purpose of this study was to compare the acute electrophysiological effects of energy drink consumption with other forms of caffeine consumption in young males. Methods We performed a randomized, double-blind, placebo-controlled, crossover study in 16 young healthy males. Each participant underwent electrocardiography assessment at pre- and post-treatment (1-hour and 2-hours) in response to 4 beverage and gum combinations: 1) energy drink + placebo gum (ED); 2) coffee + placebo gum (C); 3) placebo beverage + caffeinated energy gum (EG); and 4) placebo beverage + placebo gum (P). Caffeine content was the same in all treatment combinations and a washout period of at least 1-week was allowed among treatments. Results At 1-hour post-treatment, heart rate increased in response to ED while it decreased in response to EG (p<0.05 for ED vs. EG; Figure 1A). At 2-hours post-treatment, the increase in heart rate after ED and Coffee was significantly greater compared to the change in heart rate in response to the other treatments (p<0.05). The increase in QRS duration 1-hour post-treatment was significantly greater after ED compared to EG and Placebo (p <0.05). Corrected QT (QTc) duration was significantly reduced at 1-hour post-treatment in response to EG vs. ED (p<0.05), but was not different compared to the other treatments. At 2-hours post-treatment, QTc duration was significantly reduced in response to EG and was increased in response to Coffee (p < 0.05 for EG vs. ED and C, Figure 1C). The most prominent increase from baseline in the percentage of participants experiencing ventricular ectopy was in response to ED (Figure 1D). Conclusions The acute electrophysiological effects of energy drink, energy gum and coffee do not appear to be mediated by caffeine content. Further investigations are warranted to better understand the cardiovascular effects of these caffeinated products.