Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
The objective of this project is to elucidate the effect of L-Citrulline (L-CIT) supplementation on vascular function at rest and during rhythmic handgrip exercise and functional sympatholysis via lower-body negative pressure in postmenopausal women with elevated blood pressure and hypertension.
Using a double-blind, randomized, placebo-controlled, and crossover design, overweight or obese postmenopausal women with elevated blood pressure (BP) or hypertension will receive CIT (6 grams/day) or placebo for 2 weeks, separated by a two-week washout period.
There will be a total of 5 laboratory visits. The 1st visit will take approximately 1 hour. The 2nd - 5th visits will take about 2 hours and 15 minutes. Visit 1 will be a screening visit, visits 2 and 4 will be considered baseline visits, and visits 3 and 5 will be following the participants' two weeks of supplementation. Arterial stiffness (carotid-femoral and femoral-dorsalis pedis pulse wave velocity) and endothelial function will be assessed at rest. Additionally, brachial artery blood flow, forearm muscle oxygenation, cardiovascular hemodynamics (stroke volume, cardiac output, systemic vascular resistance), and BP will be assessed at rest, during 6 minutes of rhythmic handgrip exercise at 30% of a predetermined maximal voluntary contraction, and 2 minutes of superimposed lower body negative pressure to increase sympathetic activity.
Not provided
Not provided
Not provided
Not provided
| Label | Type | Description | Intervention Names |
|---|---|---|---|
| L-Citrulline | Experimental | L-Citrulline: 6 grams/day divided in 2 equal doses |
|
| Placebo | Placebo Comparator | Microcrystalline cellulose: 8 capsules/day divided into 2 equal doses |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| L-Citrulline | Dietary Supplement | 2 weeks of L-Citrulline supplementation (6 grams/day) |
| |
| Measure | Description | Time Frame |
|---|---|---|
| Macrovascular endothelial function at rest | Endothelial function will be assessed via brachial artery flow-mediated vasodilation (ultrasonography) during reactive hyperemia at baseline and after 2 weeks of each supplementation. | 2 weeks of each intervention |
| Microvascular endothelial function at rest | Endothelial function will be assessed via peripheral arterial tonometry (endoPAT) during reactive hyperemia at baseline and after 2 weeks of each supplementation. | 2 weeks of each intervention |
| Microvascular endothelial function at rest | Endothelial function will be assessed using forearm muscle oxygen saturation (near-infrared spectroscopy) during reactive hyperemia before and after 2 weeks of each supplementation. | 2 weeks of each intervention |
| Brachial artery blood flow at rest and during rhythmic handgrip exercise with and without lower-body negative pressure | Blood flow will be measured via Doppler ultrasound before and after 2 weeks of each intervention. | 2 weeks of each intervention |
| Forearm muscle oxygenation at rest and during rhythmic handgrip exercise with and without lower-body negative pressure | Muscle oxygen saturation will be measured via near-infrared spectroscopy before and after 2 weeks of each intervention. | 2 weeks of each intervention |
| Measure | Description | Time Frame |
|---|---|---|
| Beat-to-beat blood pressure at rest and during rhythmic handgrip exercise with and without lower-body negative pressure | Blood pressure will be measured via a finger cuff (finometer) before and after 2 weeks of each intervention. | 2 weeks of each intervention |
| Aortic hemodynamics at rest and during rhythmic handgrip exercise with and without lower body negative pressure |
Not provided
Inclusion Criteria:
Exclusion Criteria:
Not provided
Not provided
Not provided
Not provided
Not provided
| Name | Affiliation | Role |
|---|---|---|
| Arturo Figueroa | Texas Tech University | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| Texas Tech University | Lubbock | Texas | 79409 | United States |
| PubMed Identifier | Type | Citation | Retractions |
|---|---|---|---|
| 34974502 | Background | Maharaj A, Fischer SM, Dillon KN, Kang Y, Martinez MA, Figueroa A. Acute Citrulline Blunts Aortic Systolic Pressure during Exercise and Sympathoactivation in Hypertensive Postmenopausal Women. Med Sci Sports Exerc. 2022 May 1;54(5):761-768. doi: 10.1249/MSS.0000000000002848. Epub 2022 Jan 3. | |
| 36297080 | Background |
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
Not provided
| ID | Term |
|---|---|
| D006973 | Hypertension |
| ID | Term |
|---|---|
| D014652 | Vascular Diseases |
| D002318 | Cardiovascular Diseases |
Not provided
Not provided
| ID | Term |
|---|---|
| D002956 | Citrulline |
| ID | Term |
|---|---|
| D000599 | Amino Acids, Diamino |
| D000596 | Amino Acids |
| D000602 | Amino Acids, Peptides, and Proteins |
Not provided
Not provided
Cross-Over Assignment Double (Participant, Investigator) randomized, double-blind, placebo-controlled, cross-over study design
Not provided
Not provided
Not provided
| Placebo |
| Dietary Supplement |
2 weeks of microcrystalline cellulose supplementation (8 capsules/day) |
|
Aortic blood pressure and pressure waves will be assessed using radial applanation tonometry before and after 2 weeks of each intervention. |
| 2 weeks of each intervention |
| Stroke volume at rest and during rhythmic handgrip exercise with and without lower body negative pressure | Stroke volume will be assessed via impedance cardiography before and after 2 weeks of each intervention. | 2 weeks of each intervention |
| Heart rate at rest and during rhythmic handgrip exercise with and without lower body negative pressure | Heart rate will be assessed via impedance cardiography before and after 2 weeks of each intervention. | 2 weeks of each intervention |
| Systemic vascular resistance at rest and during rhythmic handgrip exercise with and without lower body negative pressure | Systemic vascular resistance will be assessed via impedance cardiography before and after 2 weeks of each intervention. | 2 weeks of each intervention |
| Central and peripheral arterial stiffness at rest | Carotid-femoral and femoral-dorsalis pedis pulse wave velocity will be measured using arterial applanation tonometry before and after 2 weeks of each intervention. | 2 weeks of each intervention |
| Forearm muscle strength | Maximal forearm muscle strength will be measured using a handgrip dynamometer before and after 2 weeks of each intervention. | 2 weeks of each intervention |
| L-arginine levels | Serum levels of l-arginine will be assessed before and after 2 weeks of each intervention. | 2 weeks of each intervention |
| Nitric oxide levels | Serum levels of nitric oxide will be assessed before and after 2 weeks of each intervention. | 2 weeks of each intervention |
| L-citrulline levels | Serum levels of l-citrulline will be assessed before and after 2 weeks of each intervention. | 2 weeks of each intervention |
| L-ornithine levels | Serum levels of l-ornithine will be assessed before and after 2 weeks of each intervention. | 2 weeks of each intervention |
| Maharaj A, Fischer SM, Dillon KN, Kang Y, Martinez MA, Figueroa A. Effects of L-Citrulline Supplementation on Endothelial Function and Blood Pressure in Hypertensive Postmenopausal Women. Nutrients. 2022 Oct 20;14(20):4396. doi: 10.3390/nu14204396. |
| 36615732 | Background | Kang Y, Dillon KN, Martinez MA, Maharaj A, Fischer SM, Figueroa A. Combined L-Citrulline Supplementation and Slow Velocity Low-Intensity Resistance Training Improves Leg Endothelial Function, Lean Mass, and Strength in Hypertensive Postmenopausal Women. Nutrients. 2022 Dec 23;15(1):74. doi: 10.3390/nu15010074. |
| 37049398 | Background | Figueroa A, Maharaj A, Kang Y, Dillon KN, Martinez MA, Morita M, Nogimura D, Fischer SM. Combined Citrulline and Glutathione Supplementation Improves Endothelial Function and Blood Pressure Reactivity in Postmenopausal Women. Nutrients. 2023 Mar 23;15(7):1557. doi: 10.3390/nu15071557. |
| 27160957 | Background | Figueroa A, Alvarez-Alvarado S, Jaime SJ, Kalfon R. l-Citrulline supplementation attenuates blood pressure, wave reflection and arterial stiffness responses to metaboreflex and cold stress in overweight men. Br J Nutr. 2016 Jul;116(2):279-85. doi: 10.1017/S0007114516001811. Epub 2016 May 10. |