title: Effect of "energy drink" consumption on hemodynamic and electrocardiographic parameters in healthy young adults.
abstract: BACKGROUND
  Energy drinks are frequently purported to improve cognitive function and concentration. However, the cardiovascular effects of these drinks have not been adequately studied.
  
  
  OBJECTIVE
  To determine the cardiac effects of a commercially available, multicomponent energy drink in healthy volunteers.
  
  
  METHODS
  Fifteen healthy adults were included in this prospective study. Individuals who had chronic medical conditions, were on chronic medication, or were pregnant or breast-feeding were excluded. Subjects abstained from caffeine for 48 hours prior to and during the study. In the morning on Day 1 of the study, while subjects were in a fasted state, baseline blood pressure (BP), heart rate (HR), and electrocardiographic (ECG) parameters were measured. Participants then consumed 500 mL (2 cans) of an energy drink and measurements were repeated 30 minutes, 1 hour, 2 hours, 3 hours, and 4 hours later. Participants then drank 500 mL of energy drink daily for the next 5 days. Day 1 protocol was repeated on Day 7.
  
  
  RESULTS
  On Days 1 and 7, maximum mean systolic BP (SBP), HR, and QTc interval occurred at 4 hours. Maximum diastolic BP (DBP) occurred at 2 hours on Days 1 and 7. Within 4 hours of energy drink consumption, on Days 1 and 7, respectively, SBP increased by 7.9% (p = 0.006) and 9.6% (p < 0.001), HR increased by 7.8% (p = 0.009) and 11.0% (p < 0.001), and QTc interval increased by 2.4% (p = 0.368) and 5.0% (p = 0.052). DBP increased by 7.0% (p = 0.046) and 7.8% (p = 0.063) within 2 hours of energy drink consumption on Days 1 and 7, respectively.
  
  
  CONCLUSIONS
  Although no significant ECG changes were observed, HR increased 5-7 beats/min and SBP increased 10 mm Hg after energy drink consumption.
authors.affiliation: Wayne State University, Detroit, MI, USA.
authors.forename: Leah
authors.initials: L
authors.lastname: Steinke
authors.forename: David E
authors.initials: DE
authors.lastname: Lanfear
authors.forename: Vishnuprabha
authors.initials: V
authors.lastname: Dhanapal
authors.forename: James S
authors.initials: JS
authors.lastname: Kalus
mesh_terms: D000328:Adult; D001628:Beverages / Q000009:adverse effects; D001794:Blood Pressure / Q000502:physiology*; D002110:Caffeine / Q000009:adverse effects; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D002110:Caffeine