Citrulline Supplementation On Vascular Responsiveness and Function in Postmenopausal Women

Not Applicable

Completed

• Conditions: Menopause
• Interventions: Dietary Supplement: L-Citrulline; Dietary Supplement: Placebo

• Registration Number: NCT05600413
• Lead Sponsor: Texas Tech University

Brief Summary

The objective of this project is to provide evidence that L-Citrulline (L-CIT) supplementation can improve vascular function at rest and in response to exercise in postmenopausal women.

Detailed Description

L-CIT is a non-essential amino acid that is a precursor to L-arginine, the substrate used to produce an important vasodilatory molecule called nitric oxide. The purpose of this study is to identify the effects of 6 grams of L-CIT for 4 weeks on vascular function (endothelial function, blood flow, muscle oxygenation, and blood pressure) at rest and in response to different stressors (cold pressor test, isometric and dynamic exercise).

Study Timeline

• Study Start: 2020-07-07
• Primary Completion: 2022-04-27
• Study Completion: 2022-04-27
• Status Verified: 2022-10
• Study First Submitted: 2022-10-24
• Study First Submitted QC: 2022-10-26
• Last Update Submitted: 2022-10-26
• Study First Posted: 2022-10-31
• Last Update Posted: 2022-10-31

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 26

Inclusion Criteria

• Postmenopausal (absence of menstruation > 1 year) between the ages of 50 - 79 years.
• Sedentary ( < 120 minutes of exercise/week)
• Resting systolic blood pressure < 150 mmHg and diastolic blood pressure < 90 mmHg
• Not participating as a subject in another study for at least 2 months prior to the study and for the duration of the study
• Willingness to abstain from food supplements 1 month prior to the start of the study and throughout the duration of the study

Exclusion Criteria

• Body mass index ≥ 40
• Currently taking more than one vasoactive drug for blood pressure control
• Cardiometabolic diseases or other chronic diseases
• Taking hormone replacement therapy 3 months prior to the study
• Current or prior use of tobacco products
• More than a moderate intake of alcohol
• Use of medications and/or supplements that may affect outcome variables
• Musculoskeletal disorders that will prevent exercise performance

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
L-Citrulline	L-Citrulline	L-Citrulline: 6 grams/day
Placebo	Placebo	Crystalline Cellulose

Primary Outcome Measures

Name	Time	Method
Muscle oxygenation during dynamic exercise	4 weeks	Muscle oxygenation will be measured using near infrared spectroscopy during dynamic exercises superimposed with the cold pressor test.
Changes in brachial and aortic blood pressure responses via automated sphygmomanometry during metaboreflex activation	4 weeks	Brachial and aortic blood pressures (systolic and diastolic) will be assessed using an arm cuff during isometric handgrip exercise and postexercise muscle ischemia.
Blood flow during dynamic exercise	4 weeks	Blood flow will be measured using ultrasound in the superficial femoral and brachial artery during dynamic exercises superimposed with the cold pressor test.
Microvascular endothelial function	4 weeks	Endothelial function will be assessed via reactive hyperemic index using the EndoPAT device.
Changes in aortic hemodynamics using pulse wave analysis during metaboreflex activation	4 weeks	The speed and reflection pressures, both representing aortic hemodynamic parameters, will be assessed using radial applanation tonometry and a validated transfer function (AtCor Medical) during isometric handgrip exercise and postexercise muscle ischemia.

Secondary Outcome Measures

Name	Time	Method
Changes in brachial and aortic blood pressure responses via automated sphygmomanometry during dynamic plantarflexion exercise and handgrip combined with the cold pressor test	4 weeks	Brachial and aortic blood pressures (systolic and diastolic) will be assessed using an arm cuff during dynamic plantarflexion exercise and handgrip combined with the cold pressor test.
Changes in aortic hemodynamics using pulse wave analysis during dynamic plantarflexion exercise and handgrip combined with the cold pressor test	4 weeks	The speed and reflection pressures, both representing aortic hemodynamic parameters, will be assessed using radial applanation tonometry and a validated transfer function (AtCor Medical) during dynamic plantarflexion exercise and handgrip combined with the cold pressor test.
Serum nitric oxide levels	4 weeks	Serum levels of nitric oxide will be assessed.

Trial Locations

Locations (1)

Texas Tech University; 🇺🇸 Lubbock, Texas, United States