AIMTo investigate whether consumption of an energy drink will acutely impair endothelial function in young healthy adults.METHODSEnergy drinks are being consumed more and more worldwide, and have been associated with some deaths in adolescents and young adults, especially when consumed while exercising. After fasting and not smoking for at least 8 h prior, eleven medical students (9 males) received an electrocardiogram, blood pressure and pulse check, and underwent baseline testing (BL) of endothelial function using the technique of endothelium-dependent flow mediated dilatation (FMD) with high-resolution ultrasound (according to recommended guidelines of the University of Wisconsin Atherosclerosis Imaging Research Program Core Laboratory). The subjects then drank an energy beverage (EB), a 24-oz can of Monster Energy, and the above was repeated at 90 min after consumption. The relative FMD (%) was calculated as the ratio between the average post-cuff release and the baseline diameter. Each image was checked for quality control, and each artery diameter was measured from the media to media points by two experts, 3 measurements at the QRS complex, repeated on 3 separate beats, and then all were averaged.RESULTSSubjects characteristics averages (given with standard deviations) include: Age 24.5 ± 1.5 years, sex 9 male and 2 female, weight 71.0 ± 9.1 kg, height 176.4 ± 6.0 cm, BMI 22.8 ± 2.7 kg/m2. The hemodynamics were as follows, BL vs EB group respectively (mean ± SD): Heart rate 65.2 ± 11.3 vs 68.2 ± 11.8 beats per minute, systolic blood pressure 114.0 ± 10.4 mmHg vs 114.1 ± 10.4 mmHg, diastolic blood pressure 68.8 ± 9.3 mmHg vs 70.6 ± 7.1 mmHg; all were not significantly different. However after drinking the EB, a significantly attenuated peak FMD response was measured (mean ± SD): BL group 5.9% ± 4.6% vs EB group 1.9% ± 2.1%; P = 0.03). Given the increased consumption of energy beverages associated with exercise in young adults, more research is needed.CONCLUSIONEnergy beverage consumption has a negative impact on arterial endothelial function in young healthy adults.

Introduction: Energy drinks are being consumed more and more worldwide, and have been associated with some deaths in adolescents and young adults, especially when consumed while exercising. The consumption of energy drinks before or during exercise might be linked to an increased risk for myocardial ischemia as a symptom of endothelial dysfunction. Energy beverage consumption and its acute effect on endothelial function is not well-studied. HYPOTHESIS Consumption of an energy drink will acutely impair endothelial function in a young healthy adult. Methods: After fasting from caffeine for at least 24 h and food for at least 8 h prior, eleven healthy non-smoker medical students (9 males), average age 24.5 years (range 23-27 years), average BMI 22.8, received an ECG, blood pressure & pulse check, and underwent baseline testing (BL) of endothelial function using the technique of endothelium-dependent flow-mediated dilatation (FMD) with high-resolution ultrasound (according to recommended guidelines of the University of Wisconsin Atherosclerosis Imaging Research Program Core Laboratory). The subjects then drank an energy beverage (EB), a 24-oz can of Monster Energy Drink®, and the above was repeated at 90 min after consumption. The FMD was calculated as the ratio between the post-cuff release diameter and the baseline diameter. Each FMD image was checked for quality control, and each artery diameter was measured as the distance between opposing tunica medias by two experts. Three measurements were taken at the QRS complex, repeated on three separate beats, and then all were averaged. Results: The hemodynamics were as follows, BL vs EB group respectively (mean+/-SD): Heart rate 65.2+/-11.3 vs 68.2+/-11.8 beats per minute, Systolic Blood pressure 114.0+/-10.4 vs. 114.1+/-10.4 mmHg, Diastolic blood pressure 68.8+/-9.3 vs. 70.6+/-7.1 mmHg; all were not significantly different. However, consumption of the EB resulted in a significantly attenuated peak FMD response (mean+/-SD): BL group 5.9+/-4.6% vs. EB group 1.9+/-2.1%; P=0.03). Conclusions: Acute exposure to an energy beverage impairs arterial endothelial function in healthy young adults. Given the increased use of these beverages associated with exercise in young adults, more research is needed.