The Effect of Short-term L-citrulline Supplementation on Blood Pressure and Arterial Stiffness

The goal of this clinical trial is to examine the effect of short-term L-Citrulline on central and peripheral blood pressure in healthy older adults. The main questions it aims to answer are:

• Does L-citrulline favorably affect blood pressure at rest and during exercise?
• Does L-citrulline favorably affect arterial stiffness?
• Does L-citrulline favorably affect muscle oxygenation at rest and during exercise?

Participants will be asked to consume L-citrulline and a placebo for six days and participate in the evaluation of their blood pressure, arterial stiffness, and muscle oxygenation before and after each intervention.

Researchers will compare L-citrulline and placebo groups to examine whether L-citrulline supplementation affects the above health parameters.

Study Overview

• Status: Completed
• Conditions: Blood Pressure
• Intervention / Treatment: Dietary supplement: L-Citrulline; Dietary supplement: Placebo

• Study Type: Interventional
• Enrollment (Actual): 12
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Cyprus
  • Nicosia, Cyprus, 1516
    • European University Cyprus

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• subject provides written informed consent.
• normal health profile.

Exclusion Criteria:

• history of musculoskeletal injury in the legs during the previous six months.
• smoker.
• consumption of any medication the last three months.
• consumption of any nutritional supplement the last three months.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: L-Citrulline; Participants will receive 6 g (3 g every 12 h) of L-citrulline (Now, L-citrulline Pure Powder) for six-days.	Dietary supplement: L-Citrulline; 6 g (3 g every 12 h) of L-citrulline for six days
Placebo Comparator: Placebo; Participants will receive 6 g (3 g every 12 h) of maltodextrin (Now, Maltodextrin) for six-days.	Dietary supplement: Placebo; 6 g (3 g every 12 h) of maltodextrin for six days

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change in aortic and brachial systolic blood pressure (rest)	Change from baseline aortic and brachial systolic blood pressure at 7 days.
Change in aortic and brachial systolic blood pressure	Change from baseline aortic and brachial systolic blood pressure at the second minute of exercise.
Change in carotid-femoral pulse wave velocity (cfPWV) (rest)	Change from baseline aortic and brachial systolic blood pressure at 7 days.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in pulse pressure (rest)		Change from baseline pulse pressure at 7 days.
Change in heart rate (rest)		Change from baseline heart rate at 7 days.
Change in augmented pressure (rest)		Change from baseline augmented pressure at 7 days.
Change in augmentation index (rest)		Change from baseline augmentation index at 7 days.
Change in forward and backward wave pressure (rest)		Change from baseline forward and backward wave pressure at 7 days.
Change in muscle oxyhemoglobin (rest)		Change from baseline oxyhemoglobin at 7 days.
Change in pulse pressure (exercise)		Change from baseline pulse pressure at the second minute of exercise.
Change in heart rate (exercise)		Change from baseline heart rate at the second minute of exercise.
Change in augmented pressure (exercise)		Change from baseline augmented pressure at the second minute of exercise.
Change in augmentation index (exercise)	The ideal augmentation index is between 20 and 80. Values above 80 are considered high, and above 121 indicate high arterial stiffness.	Change from baseline augmentation index at the second minute of exercise.
Change in forward and backward wave pressure (exercise)		Change from baseline forward and backward wave pressure at the second minute of exercise.
Change in muscle deoxyhemoglobin (exercise)		Change from baseline muscle deoxyhemoglobin at the second minute of exercise.
Change in muscle deoxyhemoglobin (rest)		Change from baseline muscle deoxyhemoglobin at 7 days.
Change in muscle oxyhemoglobin (exercise)		Change from baseline muscle oxyhemoglobin at the second minute of exercise.
Change in muscle oxyhemoglobin (rest)		Change from baseline muscle oxyhemoglobin at 7 days.

Collaborators and Investigators

• Sponsor: European University Cyprus
• Investigators: Study Director: Marios Vryonides, Dr., European University Cyprus

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2023
• Primary Completion (Actual): March 1, 2023
• Study Completion (Actual): March 1, 2023

Study Registration Dates

• First Submitted: July 18, 2023
• First Submitted That Met QC Criteria: July 26, 2023
• First Posted (Actual): August 3, 2023

Study Record Updates

• Last Update Posted (Actual): August 3, 2023
• Last Update Submitted That Met QC Criteria: July 26, 2023
• Last Verified: July 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: EUC_cit

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No