Effect of L-Citrulline on Vascular Function

Not Applicable

Completed

• Conditions: Aging; Citrulline; Blood Flow
• Interventions: Dietary Supplement: L-citrulline; Other: Placebo

• Registration Number: NCT03127917
• Lead Sponsor: Texas Tech University

Brief Summary

The objective of this project is to determine the importance of peripheral vascular function on gait performance in older adults.

Detailed Description

This project employed a placebo controlled, double-blind, crossover trial. Participants were randomized to oral L-citrulline (6 g/day) or placebo (maltodextrin) for 14 days, and switched to the other treatment for another 14 days after washout. Peripheral vascular function was assessed under conditions of rest, leg exercise, and cognitive engagement. Gait performance was assessed using clinical walking tests.

Study Timeline

• Study Start: 2015-07
• Primary Completion: 2017-03-22
• Study First Submitted: 2017-04-20
• Study First Submitted QC: 2017-04-20
• Study First Posted: 2017-04-25
• Study Completion: 2017-12-31
• Status Verified: 2018-05
• Last Update Submitted: 2018-05-01
• Last Update Posted: 2018-05-04

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 25

Inclusion Criteria

• older adults
• women and men
• aged 60-79 yrs
• must be able to swallow capsules
• fully mobile without assistive walking devices

Exclusion Criteria

• have physician diagnosed cardiovascular, pulmonary, or metabolic disease
• are current smokers
• currently taking medications affecting cardiovascular function
• have high blood pressure (>159/99 mmHG)
• have high fasting blood glucose (>110 mg/dL)
• are considered obese (body mass index ≥ 30 kg/m2)
• have orthopaedic limitations that limit walking ability
• have pacemaker or other metal objects in their body

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
CitrullinePlacebo	L-citrulline	Subjects allocated to the CitrullinePlacebo study arm received L-citrulline first, followed by placebo.
CitrullinePlacebo	Placebo	Subjects allocated to the CitrullinePlacebo study arm received L-citrulline first, followed by placebo.
PlaceboCitrulline	Placebo	Subjects allocated to the PlaceboCitrulline study arm received placebo first, followed by L-citrulline.
PlaceboCitrulline	L-citrulline	Subjects allocated to the PlaceboCitrulline study arm received placebo first, followed by L-citrulline.

Primary Outcome Measures

Name	Time	Method
Blood Flow	baseline and 2 weeks for L-citrulline and placebo	Femoral blood flow during leg exercise and carotid blood flow during mental activity measured using Doppler ultrasound. Blood-oxygen-level dependent contrast imaging of the brain using functional magnetic resonance imaging (fMRI) during cognitive functioning.

Secondary Outcome Measures

Name	Time	Method
Gait Performance	baseline and 2 weeks for L-citrulline and placebo	Usual and fast walking speeds measured during short (7m) and long (400m) distances.