Whole Body Vibration Combined With L-citrulline Supplementation on Cardiovascular Function and Body Composition
Condition: Obesity; Pre-hypertension; Hypertension
MeSH terms: Hypertension; Prehypertension
Study type: Interventional

Summary: 
      Arterial dysfunction contributes to the development of cardiovascular disease (CVD), which is
      currently afflicting millions of individuals. The use of the amino acid L-citrulline has been
      suggested as a potential aid for the treatment of CVD by increasing endothelial production of
      Nitric Oxide (NO). Whole body vibration (WBV) is new and effective form of exercise that is
      feasible for clinical populations and has been proven to decrease blood pressure (BP) and
      arterial stiffness and increase muscle mass and strength. Therefore, the purpose of this
      study was to investigate if the combination of WBV training (WBVT) plus L-citrulline
      supplementation would induce positive additive effects and would be an effective means to
      ameliorate arterial stiffness, endothelial function, BP and muscle strength/mass in
      postmenopausal women.
    

Detailed description: 
      The purpose of this study is to investigate the effects of 8 weeks combination of WBVT plus
      L-citrulline supplementation on arterial stiffness, endothelial function, BP and muscle
      strength/mass in overweight/obese postmenopausal women.

      The specific aims of the study are:

        1. To investigate if the additive effect of 8 weeks of WBVT combined with L-citrulline
           supplementation are more efficacious than either treatment alone in ameliorating
           cardiovascular disease risk factors by assessing arterial stiffness (aortic, systemic,
           and leg), aortic BP and wave reflection, and autonomic function (heart rate variability,
           vascular sympathetic activity [low-frequency power of systolic BP variability], and
           baroreflex sensitivity). Flow mediated dilation and circulating levels of adipocytokines
           (adiponectin and leptin) and endothelial-derived vasodilators (NO metabolites [NOx],
           6-keto PGFIa, insulin, and ghrelin) and vasoconstrictors (endothelin-1 [ET-1],8-iso
           PGF2a,vascular endothelium growth factor [VGEF]) will be assessed as secondary outcome
           variables.

        2. To evaluate the extent to which 8 weeks of WBVT combined with L-citrulline improves body
           composition assessed by changes in fat mass and lean mass using dual-energy x-ray
           absorptiometry and waist circumference.

        3. To determine the additive effect of 8 weeks of WBVT combined with L-citrulline
           supplementation on muscle strength. These will be evaluated using the eight-repetition
           maximum test for the leg press and chest press exercises
    

Intervention name(s): L-citrulline supplementation; Whole Body Vibration Training
Intervention type(s): Dietary Supplement; Other
Intervention description(s): The Whole body vibration training intervention consists of lower-body exercise in a vibration platform 3 times per wk for 8 wk. The subjects will perform static and dynamic exercises for the legs on the vibration platform. Dynamic exercises will be performed with slow controlled movements starting from an upright position into a 60 degree knee flexion (squat) and maximal heel elevation (toestand). Static exercises will be performed without movement in the joint angles described previously. The training volume will increase progressively over the 12-week training period by increasing the intensity of vibration, duration of the exercise set (30-60 sec), number of sets per exercise, and total duration of the training session, and decreasing the duration of rest periods (30-60 sec).The intensity of vibration and amplitude will also be increased progressively (25-30 Hz of frequency and from low to high amplitude).
Other intervention name(s): 8 weeks of L-citrulline supplementation in two doses of 3g each per day (6g per day)
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Basic Science
Keywords: whole body vibration training; L-citrulline; hypertension; obesity; arterial function; arterial stiffness; autonomic function; endothelial function