Impact of energy drink versus coffee consumption on periodic repolarization dynamics: an interventional study

Caffeinated beverages are consumed daily throughout the world. Caffeine consumption has been linked to dysfunction of the autonomic nervous system. However, the exact effects are still insufficiently understood.

Sixteen healthy individuals were included in the present non-randomized cross-over interventional study. All study subjects consumed a commercial energy drink (containing 240 mg caffeine), and in a second independent session coffee (containing 240 mg caffeine). High-resolution digital ECGs in Frank-lead configuration were recorded at baseline before consumption, and 45 min after consumption of the respective beverage. Using customized software, we assessed ECG-based biomarker periodic repolarization dynamics (PRD), which mirrors the effect of efferent cardiac sympathetic activity on the ventricular myocardium.

The consumption of energy drinks resulted in an increase in PRD levels (3.64 vs. 5.85 deg²; p < 0.001). In contrast, coffee consumption did not alter PRD levels (3.47 vs 3.16 deg², p = 0.63). The heart rates remained unchanged both after coffee and after energy drink consumption. Spearman analysis showed no significant correlation between PRD changes and heart rate changes (R = 0.34, p = 0.31 for coffee, R = 0.31, p = 0.24 for energy drink).

Our data suggests that sympathetic activation after consumption of caffeinated beverages is independent from caffeine and might be mediated by other substances.

NCT04886869, 13 May 2021, retrospectively registered.