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Completed

NCT Number: NCT05600413

Citrulline Supplementation On Vascular Responsiveness and Function in Postmenopausal Women

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.

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Key information

Conditions

Menopause

Age range

50 year–79 year

Sex eligibility

Female

Study type

Interventional

Phase

Not applicable

Primary location

Texas Tech University

Lubbock, Texas, 79409, United States

About this study

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).

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

L-citrulline

Dietary Supplement

4 weeks of L-Citrulline supplementation (6 grams/day)

Placebo

Dietary Supplement

4 weeks of Placebo (crystalline cellulose)

Primary outcomes

  1. Microvascular endothelial function

    Time frame: 4 weeks

    Endothelial function will be assessed via reactive hyperemic index using the EndoPAT device.

  2. Changes in brachial and aortic blood pressure responses via automated sphygmomanometry during metaboreflex activation

    Time frame: 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.

  3. Changes in aortic hemodynamics using pulse wave analysis during metaboreflex activation

    Time frame: 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.

  4. Blood flow during dynamic exercise

    Time frame: 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.

  5. Muscle oxygenation during dynamic exercise

    Time frame: 4 weeks

    Muscle oxygenation will be measured using near infrared spectroscopy during dynamic exercises superimposed with the cold pressor test.

Secondary outcomes

  1. Serum nitric oxide levels

    Time frame: 4 weeks

    Serum levels of nitric oxide will be assessed.

  2. Changes in brachial and aortic blood pressure responses via automated sphygmomanometry during dynamic plantarflexion exercise and handgrip combined with the cold pressor test

    Time frame: 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.

  3. Changes in aortic hemodynamics using pulse wave analysis during dynamic plantarflexion exercise and handgrip combined with the cold pressor test

    Time frame: 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.

Sponsors and collaborators

Lead sponsor

Texas Tech University

Other

Registry information

Official study title

L-Citrulline Supplementation to Improve Vascular Function and Responsiveness at Rest and During Exercise in Postmenopausal Women

Important dates

Study start
2020
Primary completion
2022
Study completion
2022
First posted
Oct 31, 2022
Registry last updated
Oct 31, 2022

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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