Effect of Oral Caffeine and L-Citrulline Supplementation on Arterial Function in Healthy Males
|The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.|
|ClinicalTrials.gov Identifier: NCT02214290|
Recruitment Status : Completed
First Posted : August 12, 2014
Results First Posted : December 29, 2020
Last Update Posted : December 29, 2020
|Condition or disease||Intervention/treatment||Phase|
|Hypertension Healthy||Drug: Caffeine Drug: Placebo Dietary Supplement: L-citrulline||Not Applicable|
The specific aims of this study are:
AIM 1: To examine the effects of the acute ingestion of 200mg caffeine (tablets) on arterial function in young adults. The working hypothesis is that acute caffeine intake would increase brachial, ankle and aortic BP, PWV (aortic and leg), and wave reflection. In order to test this hypothesis, the investigators will perform non-invasive measurements of arterial stiffness (aortic and leg PWV) and pulse wave analysis (aortic BP and AIx) using applanation tonometry of the radial artery 30, 45, and 60 minutes following caffeine ingestion.
AIM 2: To determine the effectiveness of L-citrulline supplementation to attenuate the acute cardiovascular effects of caffeine ingestion. The working hypothesis is that 7 days of L-citrulline supplementation will attenuate the unfavorable arterial responses (increases in BP, PWV, and wave reflection) to acute caffeine ingestion. In order to test this hypothesis, the investigators will perform the same procedures previously specified in AIM 1.
Description of the study:
Sixteen healthy young men 18-40 years of age will be enrolled in this study. Participants with CVD history, resting BP (> 160/100 mmHg), recent history of smoking, or considered competitive athlete will be excluded from the study. All subjects will refrain from food and caffeine for > 8 hours and from exercise for > 24 hours before testing.
Following an initial screening, arterial function measurements will be collected. Measurements will be assessed at baseline following 10 minutes of rest in the supine position and then again at 30, 45, and 60 minutes after 200 mg caffeine or placebo ingestion. Participants will receive caffeine or placebo supplementation on two separate visits with a minimum of 48 hours in between sessions. Following the acute phase of the study, subjects will be randomized to consume L-citrulline or placebo for 7 days given at 6 grams/day. Following the same protocol as the acute phase with 200 mg caffeine, measurements will be collected before and after the 7 day supplementation period.
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||16 participants|
|Intervention Model:||Crossover Assignment|
|Masking:||Double (Participant, Outcomes Assessor)|
|Official Title:||Effect of Oral Caffeine and L-Citrulline Supplementation on Arterial Function in Healthy Males|
|Study Start Date :||September 2012|
|Actual Primary Completion Date :||March 2014|
|Actual Study Completion Date :||March 2014|
Active Comparator: Caffeine
200 mg caffeine tablet produced by CVS Pharmacy, USA
A 200 mg caffeine tablet was given to subject to examine the drugs effect on arterial function.
Other Name: Caffeine tablet (CVS Pharmacy)
Placebo Comparator: Placebo
Placebo pill produced by NOW FOODS, USA
A 750 mg placebo capsule (maltodextrin) was given to subjects to examine the effect of the drug on arterial function.
Other Name: Placebo from NOW FOODS, USA
L-citrulline capsule (750 mg) provided by NOW FOODS
Dietary Supplement: L-citrulline
L-citrulline was used to examine the effect of the supplement on arterial function.
Other Name: L-citrulline (750 mg/capsule)
- Aortic Blood Pressure [ Time Frame: Baseline and Day 7 (Calculated change between rest and 30 minutes post-caffeine ingestion at these time points) ]Aortic blood pressure at rest and 30 minutes after acute ingestion of 200 mg of caffeine before and after 7 days of either 6g/day of Citrulline or 6 g/day of Placebo.
- Changes in Reflected Wave Pressure (P2) [ Time Frame: Baseline and Day 7 (Calculated change between rest and 30 minutes post-caffeine ingestion at these time points) ]Reflected wave pressure at rest and 30 minutes after ingestion of 200mg of caffeine after 7 days supplementation of 6g/day of either L-Citrulline or Placebo.
- Changes in Femoral-ankle Pulse Wave Velocity After 7 Days of Either L-Citrulline or Placebo (6g/Day) [ Time Frame: Baseline and Day 7 (Calculated change between rest and 30 minutes post-caffeine ingestion at these time points) ]Femoral-ankle pulse wave velocity at rest and 30 minutes after ingestion of 200mg of caffeine after 7 days supplementation of 6g/day of either L-Citrulline or Placebo.
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02214290
|Principal Investigator:||Arturo Figueroa, M.D. Ph.D||Florida State University|