L-citrulline Supplementation & Cold Exposure

NCT01462591 | Completed Phase 1

• 1 other identifier: HSC2011.6686
• Study Type: interventional
• Target: 16
• Locations: 1 country
• Sites: 1

Brief Summary

Cardiovascular disease (CVD) is considered the primary cause of death in the developed world. Large scale epidemiological studies indicate that prevalence of hypertension along with adverse cardiovascular events peak during the winter months. Moreover, during the winter months outdoor activities and physical stressors such as exercise have been associated with higher cardiovascular mortality when compared to other periods of the year. Although low environmental temperatures have been implicated as the triggering factor for cardiovascular complications, the mechanisms on how cold exposure increase cardiovascular morbidity and mortality remain to be elucidated. However, new research suggests that cold exposure may induce increases in cardiac sympathetic activity, endothelial damage and increased arterial stiffness of central arteries. Cardiovascular drugs including antihypertensive pharmacological agents seem to be inefficient to provide appropriate therapeutic effects during cold exposure. Therefore, it is imperative to propose alternative non-pharmacological therapies intended to prevent the detrimental effects of low environmental temperatures on cardiovascular function. Recently, oral supplementation of the amino acid L-citrulline has been proposed as an effective therapeutic adjuvant for the treatment of hypertension. L-citrulline is known to enhance the bioavailability of L-arginine levels and increase endothelial nitric oxide (NO) production, one of the main modulators of vascular tone and blood pressure (BP). L-citrulline supplementation has been shown to increase endothelial function, reduce BP, and ameliorate endothelial oxidative damage without any adverse effects. Our group has demonstrated that L-citrulline supplementation attenuates the BP response to cold exposure (the cold pressor test, CPT). These studies suggest that L-citrulline supplementation may be a feasible therapeutic aid in order to prevent cardiovascular complications associated with cold exposure. However the potential cardioprotective effects of L-citrulline supplementation during cold exposure with exercise have yet to be evaluated. It is hypothesized that L-citrulline supplementation would reduce arterial stiffness and blood pressure (BP) responses to physiological stress (cold exposure). This study may lead to the development of an adjunct therapy for the prevention and management of cardiovascular adverse events that are particularly increased during the winter months.

Conditions

Hypertension

Keywords

wave reflection; augmentation Index; heart rate variability; wasted left ventricular energy

Outcome Measures

Primary Outcomes (1)

• Blood Pressure

  By measuring brachial and central (aortic and carotid) BP at rest and during physiological stress (cold exposure and handgrip test)

  6 weeks

Secondary Outcomes (1)

• Autonomic control of heart rate

  6 weeks

Study Arms (2)

L-citrulline

EXPERIMENTAL

L-citrulline (100mg/kg of body weight per day for 2 weeks)

Dietary Supplement: L-citrulline

Maltodextrin

PLACEBO COMPARATOR

6g/day of placebo (maltodextrin)

Dietary Supplement: L-citrulline

Interventions

L-citrulline DIETARY_SUPPLEMENT

2 weeks of L-citrulline supplementation (100mg/kg of body weight).

L-citrulline; Maltodextrin

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Men
• Blood pressure lower than 140/90mmHg
• Age 18 to 35 years
• BMI 20-39 kg/m2

You may not qualify if:

• Blood Pressure \>160/100 mmHg
• Asthma
• Glaucoma
• Herpes simplex
• Uncontrolled diabetes
• Neurological disease
• Cardiovascular disease
• Inflammatory disease
• Kidney disease
• Hormone replacement therapy (HRT)
• Amino acid/vitamin supplementation\\
• Corticosteroids or non-steroidal anti-inflammatory drugs
• Any drug known to affect BP or heart rate
• Glycemic control drugs
• Lipids reducing drugs

Sponsors & Collaborators

• Florida State University: lead

Study Sites (1)

FSU College of Human Sciences

Tallahassee, Florida, 32306, United States

Location

MeSH Terms

Conditions

Hypertension

Interventions

Citrulline

Condition Hierarchy (Ancestors)

Vascular Diseases; Cardiovascular Diseases

Intervention Hierarchy (Ancestors)

Amino Acids, Diamino; Amino Acids; Amino Acids, Peptides, and Proteins

Study Officials

• Marcos A Sanchez-Gonzalez, M.D.

  The Florida State University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: October 27, 2011
• First Posted: October 31, 2011
• Study Start: May 1, 2011
• Primary Completion: December 1, 2011
• Study Completion: May 1, 2012
• Last Updated: August 5, 2014

Record last verified: 2014-08

Locations

US (1)