Recruiting

Testosterone & Endothelial Function

Sponsor:

Craig Hospital

Code:

NCT07227740

Conditions

Spinal Cord Injuries

Endothelial Dysfunction

Testosterone Deficiency

Eligibility Criteria

Sex: Male

Age: 18 - 70+

Healthy Volunteers: Not accepted

Interventions

Intra-arterial Infusion of Vasoactive Agents

Intra-arterial Vitamin C Infusion

Blood Sampling

Study Details

Brief summary:

Heart attacks and strokes are among the most common causes of premature death in individuals living with spinal cord injury (SCI) and appear to occur earlier in life. The factors that lead to the heighten and accelerated risk of heart attacks and strokes in adults living with SCI remain poorly understood. The investigators aim to uncover why this happens and find ways to prevent it. Our research focuses on how important cells which line blood vessels, called endothelial cells, function after SCI. The investigators test endothelial function in live conscious people with SCI. The investigators also study signaling molecules endothelial cells release called endothelial cell derived microvesicles (EMVs), which the investigators can measure in blood to tell us the health of endothelial cells. By using these rigorous tests of vascular function, the investigators have determined that endothelial cells appear dysfunctional after SCI. The investigators also know that many men with SCI have low testosterone levels. Our team has studied testosterone's effects on endothelial dysfunction and believe low testosterone may be contributing to endothelial dysfunction after SCI. By understanding these mechanisms, the investigators hope to improve the lives of those living with SCI and reduce their risk for heart attacks and strokes. The investigators propose to study the influence of testosterone on endothelial function by using state-of-the-art clinical and laboratory experiments to assess endothelial function in men with SCI with low and normal testosterone levels.

Conditions

Spinal Cord Injuries

Endothelial Dysfunction

Testosterone Deficiency

Study ID

NCT07227740

Start date

Jul 15, 2025

Status verified date

Nov, 2025

Completion date

Jul 14, 2028

Anticipated

Primary completion date

Jul 14, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Male

Age: 18 - 70+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Between ages 18-89 years of age
  • Male Sex
  • History of motor complete (AIS A/B) paraplegia (NLI T3 or Below)
  • Time since injury <6 months at time of enrollment (Subacute injury)
  • Testosterone Deficiency defined as < 300ng/dL

Exclusion Criteria:

  • Overt cardiovascular disease assessed by a) medical history, b) physical examination c) electrocardiogram
  • Anaphylaxis to betadine, lidocaine, iodine
  • Active infection at time of enrollment.
  • Recent surgery (<1 month) at time of enrollment.
  • History smoking tobacco (currently or in the past 12 months)
  • History of more than low-risk history of alcohol consumption
  • History of drug abuse
  • History of use of cardiovascular-acting (i.e. statins, beta-blockers) therapeutics
  • History of other health habits, medications, and supplements that could influence the outcome measures deemed by principal investigators and investigative team.

Study Design

Enrollment

48 participants

Anticipated

Interventions and Outcome Measures

Arms

Adult Male with Subacute Traumatic Spinal Cord Injury with Normal Testosterone

24 male participants of all races and ethnic backgrounds aged 18-89 years with a history of spinal cord injury and diagnosed with normal testosterone

Adult Male with Subacute Traumatic Spinal Cord Injury with Low Testosterone

24 male participants of all races and ethnic backgrounds aged 18-89 years with a history of spinal cord injury and diagnosed with low testosterone

Interventions

Intra-arterial Infusion of Vasoactive Agents

A catheter is placed in the brachial artery of the non-dominant arm, and small doses of vasoactive drugs acetylcholine, isoproterenol, sodium nitroprusside are infused. Forearm blood flow will be measured using venous occlusion plethysmography. The purpose of this procedure is to assess endothelium-dependent and independent vasodilation by stimulating different vascular pathways. The acetylcholine infusion is to test muscarinic receptor, nitro oxide dependent, endothelium-dependent vasodilation. Isoproterenol was selected to stimulate tissue plasminogen activator based on its specificity and effectiveness at eliciting local and rapid tissue plasminogen activator release in adult humans. Sodium nitroprusside infusion is to assess endothelium-independent vasodilation.

Intra-arterial Vitamin C Infusion

Vitamin C, a potent antioxidant, will be infused into the forearm and forearm blood flow will be re-evaluated to determine whether oxidative stress contributes to endothelial dysfunction.

Blood Sampling

Blood will be sampled from the antecubital vein (\~50 mL) for biomarker analysis. This is to assess circulating biochemical and molecular indicators of vascular health and inflammation including levels of endothelial cell derived microvesicles.

Primary outcome measure

  • Endothelium-dependent vasodilation [ Time Frame: Measured at baseline (without acetylcholine) and immediately after each acetylcholine dose for 3-5 minutes. ]
  • Endothelium-independent vasodilation [ Time Frame: Measured at baseline (without sodium nitroprusside) and immediately after each sodium nitroprusside dose for 3-5 minutes. ]
  • Tissue plasminogen activator release [ Time Frame: Measured at baseline and immediately after each isoproterenol and sodium nitroprusside dose for 3-5 minutes. ]
  • Endothelial cell-derived microvesicles concentration [ Time Frame: Baseline ]
  • Endothelial cell-derived microvesicles effects of human coronary artery endothelial cells nitric oxide bioavailability. [ Time Frame: Baseline ]
  • Endothelial cell-derived microvesicles effects of human coronary artery endothelial cells reactive oxygen species and antioxidant capacity [ Time Frame: Baseline ]

Central Contacts and Locations

Central contacts

Genevieve Madera, BS

17203454640Gmadera@craighospital.org

Andrew Park, MD

303-789-8101apark@craighospital.org

Locations

Craig Hospital

Recruiting

Englewood, Colorado, United States, 80113

Contacts

Genevieve Madera, BS

7203454640Gmadera@craighospital.org

Andrew Park, MD

303-789-8101apark@craighospital.org

Principal Investigator:

Andrew Park, MD

More Information

Sponsor

Craig Hospital

Last update posted

Nov 21, 2025

Last verified

Nov, 2025

Keywords

  • spinal cord injury
  • endothelial dysfunction
  • testosterone deficiency
  • extracellular vesicles
  • microvesicles
  • vasodilation
  • fibrinolysis

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Craig Hospital on 2025-11-21.