Consumption of energy beverage is associated with attenuation of arterial endothelial flow-mediated dilatation

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.

Influence of cardiorespiratory fitness and body composition on resting and post-exercise indices of vascular health in young adults

Poor cardiorespiratory fitness may mediate vascular impairments at rest and following an acute bout of exercise in young healthy individuals.This study aimed to compare flow mediated dilation(FMD)and vascular augmentation index(AIx75)between young adults with low,moderate,and high levels of cardiorespiratory fitness before and after an acute bout of aerobic exercise.Forty-three participants(22 men;21 women)between 18 and 29 years of age completed the study.Participants were classified into low,moderate,and high health-related cardiorespiratory fitness groups according to age-and sex-based relative maximal oxygen consumption(V_O2 max)percentile rankings.FMD was performed using Doppler ultrasound and AIx75 was performed using pulse wave analysis at baseline and 60-min after a 30-min bout of treadmill running at 70%V_O2 max.A significant interaction(p=0.047;ηp 2=0.142)was observed,with the moderate fitness group exhibiting a higher FMD post-exercise compared with baseline([6.7%3.1%]vs.[8.5%2.8%],p=0.028;d=0.598).We found a significant main effect of group for AIx75(p=0.023;ηp 2=0.168),with the high fitness group exhibiting lower AIx75 compared to low fitness group([10%10%]vs.[2%10%],respectively,p=0.019;g=1.07).This was eliminated after covarying for body fat percentage(p=0.489).Our findings suggest that resting FMD and AIx75 responses are not significantly influenced by cardiorespiratory fitness,but FMD recovery responses to exercise may be enhanced in individuals with moderate cardiorespiratory fitness levels.