Background: Cardiovascular events associated with energy drink consumption have been reported, but few data exist to delineate the hemodynamic effects of energy drinks.
Objective: To compare the effects of an energy drink versus caffeine supplementation on blood pressure (BP) indices as measured by 24-hour ambulatory BP monitoring (ABPM).
Methods: Healthy, nonsmoking, normotensive volunteers (aged 18-45 years) taking no medications were enrolled in a single-center, open-label, 2-period crossover pilot study. During each study period, subjects received either an energy drink (Red Bull Energy Drink, each dose containing 80 mg of caffeine and 1000 mg of taurine in an 8.3-oz serving) or a control (compounded caffeine solution, each dose containing 80 mg of caffeine solution in 8 oz of bottled water) at 0800, 1100, 1500, and 1900 hours and underwent 24-hour ABPM. The study periods were separated by a washout period (4-30 days). Mean 24-hour, daytime, and nighttime systolic (SBP), diastolic (DBP), and mean arterial (MAP) BP; BP load; and percent nocturnal dipping were compared between study periods.
Results: Nine subjects (5 females, mean [SD] age 27.7 [5.0] years) completed the study. Mean 24-hour SBP (123.2 vs 117.4 mm Hg, p = 0.04), DBP (73.6 vs 68.2 mm Hg, p = 0.02), and MAP (90.1 vs 84.8 mm Hg, p = 0.03) were significantly higher during energy drink supplementation versus caffeine supplementation. Daytime DBP (77.0 vs 72.0 mm Hg, p = 0.04) also was significantly higher with the energy drink versus caffeine supplementation. Trends in higher daytime SBP (127.0 vs 121.9 mm Hg, p = 0.05) and MAP (93.6 vs 88.6 mm Hg, p = 0.05) were recorded with energy drink supplementation versus caffeine supplementation. Nighttime SBP and DBP loads were significantly higher with the energy drink, but nocturnal dipping did not differ significantly between study periods.
Conclusions: Single-day energy drink supplementation increased mean 24-hour and daytime BP compared to caffeine control in this pilot study. Additional research is warranted to better understand the hemodynamic effects of energy drink consumption.