Increased Static Postural Sway After Energy Drink Consumption
Condition: Disorder
Study type: Interventional

Summary: 
      Background & Purpose: Energy drinks consumption continues to grow since its appearance in the
      United States in 1997. Available evidence indicates that caffeine, their main ingredient, can
      alter the central nervous system (CNS). However, it is unknown how energy drinks adjust the
      CNS postural control mechanism. The purpose of this study was to investigate how energy
      drinks can affect postural control after sensory perturbations during stance.

      Methods: 20 healthy adults, (11 males; 9 females) averaging 26.1 years of age, stood on a
      pressure mat, which measured center of pressure (CoP), anteroposterior (AP) and mediolateral
      (ML) postural sways during eight different balance tests (BALT's). BALT's were designed to
      alter or cancel the systems involved in postural control: visual, vestibular and
      somatosensory. Subjects were randomly assigned to a caffeine group and an energy drink group.
      MANOVA analysis was performed for all variables of interest.
    

Detailed description: 
      Methods General Protocol

      After signing the informed consent and reviewing the inclusion and exclusion criteria,
      participants were subjected to a preliminary screening of participation using a list of
      questions and the American college sports medicine Health / Fitness Facility Questionnaire.
      This questionnaire's purpose is to ensure the safety of the participants to engage in
      physical activity by assessing the subjects and family history of cardiovascular diseases.
      Afterwards, the Investigators assessed subjects' vital signs, blood pressure, pulse, and
      spO2, to ensure subjects were able to participate in physical activity safely ingest a
      moderate intake of caffeine without complications. Since postural control is negatively
      correlated with increased adiposity, weight and height data were measured to obtain a
      classification according to the Body Mass Index. A range of 18.5 to 29.9 was required to
      participate. During the physical examinations the subjects also performed a Romberg test to
      rule out any obvious impairment in static balance, a modified Sit and Reach Test for the
      evaluation of functional flexibility, Sit to Stand Test (30 Seconds) for the assessment of
      lower limb functional strength, and a Step Test to evaluate the response of the
      cardiovascular system to a submaximal cardio test. After the physical examination, the
      participants had a rest period between 10-20 minutes before starting the balance tests
      protocol of (BALT's).

      Procedure

      Each participant from both groups performed eight balance tests (BALT's) which alter or
      cancel, individually or combined, sensory input from the sensory systems involved in postural
      control. The order of the tests was changed systematically between subjects; therefore, they
      did not perform the tests in the same order to eliminate external factors such as fatigue or
      accommodation to the BALT's, which could alter the results. The BALT's were conducted on the
      (TekScan, Boston, MA) a pressure platform containing sensors that measure a displacement of
      the center of pressure in centimeters squared (cm2) (CoP), anteroposterior (AP), and
      mediolateral (ML) sway in centimeters (cm). The data collected from the pressure mat was
      analyzed with Sway Analysis Module (SAM) software designed for this purpose. The subjects
      stood for 30 seconds on the pressure platform during each test.

      The first 4 BALT's were carried out by placing the pressure platform on the floor, a stable
      surface. These tests were: 1) Open Eyes (EO) with a fixed point to evaluate all the systems
      involved in the postural control (visual, vestibular, somatosensory); 2) Eyes Closed (EC) to
      evaluate the vestibular and somatosensory system, while eliminating the visual sensory input;
      3) Eyes Open while actively moving the head up and down (HUD) to evaluate the visual and
      somatosensory system, while altering the vestibular system with head movements (EO HUD) (For
      HUD movements a metronome 2/4 60 BPM was used to maintain a fixed frequency of about one spin
      per second in motion); 4) Eyes closed and actively moving the head up and down (EC HUD) to
      assess the effect of removing the visual input, in combination of an alteration of the
      vestibular system with the head up and down movements.

      The remaining 4 BALT's were the same as the four previously mentioned tests with the
      difference that the subject stood on an unstable surface (foam mat) that was placed on top of
      the pressure platform to alter the somatosensory (proprioceptive) system.

      After the initial eight pre BALT's, to the experimental group, 160 mg of caffeine was given
      through one energy drink (16 ounces). Monster energy drink was chosen because, unlike other
      energy drink brands, the label of Monster Energy drink exhibits the guarana additive, a
      potential CNS stimulant, in its nutritional label. To the control group, Investigators gave a
      caffeine pill of 200mg, a moderate dose in healthy adults which has been used in numerous
      studies on different topics and has not been associated with adverse effects such as
      toxicity, cardiovascular effects, behavior changes, among other things. Because peak
      absorption of caffeine is reached within 30-45 minutes after the ingestion of caffeine/energy
      drink, there was a rest period of 30 minutes. Vital signs were measured after the rest
      period, for the third time. The same 8 BALT's were then performed, for post ingestion
      results.
    

Intervention name(s): Caffeine versus Energy Drink
Intervention type(s): Other
Intervention description(s): Caffeine group consumed 200mg of caffeine one time, while the energy drink group consumed 1 16 ounces of energy drink.
Intervention MeSH terms: Caffeine
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: 20 healthy adults, (11 males; 9 females) averaging 26.1 years of age, stood on a MatScan™ pressure mat, which measured center of pressure (CoP), anteroposterior (AP) and mediolateral (ML) postural sways during eight different balance tests (BALT's). BALT's were designed to alter or cancel the systems involved in postural control: visual, vestibular and somatosensory. Subjects were randomly assigned to a caffeine group and an energy drink group. MANOVA analysis was performed for all variables of interest.
Masking: None (Open Label)
Primary purpose: Screening
Keywords: Fluid; Balance