Abstract 11063: Evaluation of Different Energy Drinks and Coffee on Endothelial Function

Abstract

Background: Endothelial function is an important component of vascular health. There have been differing reports on the effect of energy drink on endothelial function. The aim of this study was to evaluate the effect of 3 commonly consumed energy drinks on endothelial function. As the main active ingredient of energy drinks is caffeine, a comparison was made to coffee, a drink with substantial caffeine content. The hypothesis tested was that energy drinks differ in effect on endothelial function due to differing ingredients. Methods: Endothelial function was evaluated in 16 healthy volunteers employing an EndoPAT device (Itamar Medical, Israel) that measures digital peripheral arterial tonometry and reports endothelial function as the Reactive Hyperemia Index (RHI). Volunteers (Age: 25±5 years, 7 females, 9 male, weight: 72±11 kg, height: 169±10 cm, systolic blood pressure: 121±7 mmHg, and diastolic blood pressure: 80±6 mmHg) received the energy drink sequence (3) or coffee (16). Energy drink or coffee were given at least 2 days apart. Drinks studied were 250 mL Red Bull containing 80 mg caffeine, 57 mL “5-hour Energy” containing 230 mg caffeine, a can of 355 mL “NOS” energy drink containing 120 mg caffeine and a cup of 473 mL coffee containing 240 mg caffeine, taken in a random order. Studies were performed before drink (baseline) at 1.5 and 4 hrs. post drink. Results: Two of the energy drinks (Red Bull and 5-hour Energy) significantly improved endothelial function at 4 hrs. post drink, while one (NOS) as well as coffee did not change endothelial function significantly. RHI increased by 40±7% (p=0.01) and 48±12% (p=0.019) following 5-hour Energy and Red Bull respectively. RHI decreased following NOS by 13±8% (p=0.101) and increased by 7±30% (p=1.000) following coffee. Conclusion: Improvement in endothelial function as measured by RHI is seen with some but not all energy drinks. Coffee does not show a significant improvement in endothelial function as measured by RHI.