Clinical trial NCT05722860: L-Citrulline and Endothelial Function
Official title: Effect of Oral L-Citrulline on the Peripheral and Central Endothelial Function in Young and Older Adults
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: PHASE1
Conditions: Aging
Keywords: L-Citrulline
Lead sponsor: University of Oklahoma
Sponsor class: OTHER
First posted: 2023-02-10
Enrollment: 30
Sex: ALL
Minimum age (years): 18
Maximum age (years): 90
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Intervention model description: Open label single arm study
Primary purpose: BASIC_SCIENCE

Brief summary: The effect of L-Citrulline is well studied in relation to muscle strength, exhaustion, exercise performance, and endothelial function in health and disease. This study will extend current body of knowledge and will investigate the effect of L-Citrulline on brain vascular function.

Detailed description: Endothelial function is associated with nitric oxide (NO) availability for vasodilation, blood pressure and blood flow regulation, and vascular health. A large body of evidence demonstrates that aging is associated with a decrease in bioavailability of NO, with more pronounced decrease in sedentary individuals. NO can be produced via the NO synthase (NOS) enzymes, which catalyze the conversion of L-Arginine - a semi-essential amino acid found in fish, nuts and legumes amongst others - to L-Citrulline and produce NO as an endproduct. While the effect of L-Citrulline is extensively studied in relation to muscle strength, exhaustion, exercise performance, as well as on endothelial function in healthy and diseased individuals (including obese and those with heart failure), the effect of L-Citrulline on brain vascular function is not well studied.

Eligibility criteria: Inclusion Criteria:

* Age 21-45 and ≥55-90 years of age
* Adequate hearing and visual acuity to participate in the examinations
* Ability to read and write in English
* Competence to provide informed consent

Exclusion Criteria:

* Active CNS disease including multiple sclerosis, uncontrolled seizures, active brain cancer
* Cerebrovascular accident other than TIA within 60 days prior to Visit 0
* Major psychiatric disease, including major depression not currently controlled on medications, alcohol or drug abuse
* Treatment with other Citrulline enhancers (L-Arginine, L-Citrulline Malate) within 4 weeks prior to Visit 0
* Any other medical condition which, in the opinion of investigator, would render the patient inappropriate or too unstable to complete the study protocol

Primary outcomes:
measure: Change in neurovascular coupling using functional near infrared spectroscopy (fNIRS)
timeFrame: 1 week
measure: Change in neurovascular coupling using the dynamic retinal vessel analysis
timeFrame: 1 week
measure: Change in neuronal activity
timeFrame: 1 week
Secondary outcomes:
measure: Change in microvascular endothelial function
timeFrame: 1 week
measure: Change in macrovascular endothelial function
timeFrame: 1 week
measure: Change in Glycocalyx - perfused boundary region
timeFrame: 1 week
measure: Change in capillary density
timeFrame: 1 week
measure: Change in red blood cell velocity
timeFrame: 1 week
measure: Change in grip strength
timeFrame: 1 week
measure: Change in Attention
timeFrame: 1 week
measure: Change in Working Memory
timeFrame: 1 week
measure: Change in Executive Function
timeFrame: 1 week
measure: Change in Processing Speed
timeFrame: 1 week
measure: Blood collection
timeFrame: 1 week
Other outcomes:
Locations:
city: Oklahoma City
country: United States
facility: Andriy Yabluchanskiy
state: Oklahoma
Study officials:
affiliation: University of Oklahoma
name: Andriy Yabluchanskiy, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References: