Cardiovascular Outcomes of Low Testosterone (CardioVOLT)

Cardiovascular Consequences of Hypogonadism in Men

This study plans to learn more about heart and vascular aging in men. In some men as they get older, testosterone levels fall below the normal range for young men. Also, as men get older cardiovascular health worsens. This can lead to high blood pressure and heart disease. In this study we want to find out what causes cardiovascular health to worsen in older men. Also we want to find out what happens when testosterone levels are lowered for a short time. Specifically, we want to see if the reduction in cardiovascular health in older men with low testosterone levels is because of damage to mitochondria. Mitochondria are the main power supply of the cells in our body. The results from this study will help to understand why cardiovascular health declines in older men with low testosterone levels compared to younger men and older men who have higher testosterone levels. Knowing this information will help to develop therapies to prevent heart disease in men.

Study Overview

• Status: Active, not recruiting
• Conditions: Hypogonadism
• Intervention / Treatment: Drug: Acyline; Drug: Placebo Gel; Drug: Placebo Tablet; Drug: Testosterone Gel; Drug: Arimidex

Detailed Description

Cardiovascular (CV) aging, featuring large artery stiffening, endothelial dysfunction, and impaired left ventricular (LV) diastolic function, is a major risk factor for the development of cardiovascular diseases (CVD). Male aging is associated with a gradual and variable decline in serum testosterone (T) and low T is associated with accelerated CV aging. The purpose of this research is to determine the key functional mechanisms underlying accelerated CV aging in older men with low T. The overall hypothesis is that mitochondrial dysfunction and oxidative stress are mechanisms underlying the apparent accelerated CV aging in older men with low T. To test this hypothesis Aim 1 will use cross-sectional comparisons of young and older men with normal T (≥400 ng/dl), and older men with chronically low T (<300 ng/dl). To better isolate the effects of low T from factors that change with aging and chronic low T, Aim 2 will expand on the cross-sectional comparisons by assessing measures of CV function, oxidative stress burden and mitochondrial function in older men with normal T before and after randomization to short-term (28 d) gonadal suppression (gonadotropin releasing hormone antagonist, GnRHant) + placebo (PL), GnRHant+T alone, or GnRHant+T+aromatase inhibitor (AI). AI will control for the effects of aromatization of T to estradiol (E2), and thereby isolate T effects while suppressing E2, a potent modulator of CV function. The results from this research should provide new mechanistic insight into the processes that mediate the impairment in CV function at the cellular and systemic level in older men with low T. These studies will lead to a better understanding of the independent role of T in age-related changes in CV function and the mechanisms of action, which will help guide future sex-specific therapies for the prevention of CVD.

• Study Type: Interventional
• Enrollment (Estimated): 379
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Colorado
    • Denver, Colorado, United States, 80045
      • University of Colorado CCTSI CTRC

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. Men aged 18-40 years and 50-75 years
2. Chronically low testosterone group will have testosterone concentrations <300 ng/dl, and young and older normal testosterone groups will have testosterone levels 400-1000 ng/dl
3. No use of sex hormones for at least 1 year
4. Body mass index <40 kg/m2
5. Nonsmokers
6. Resting blood pressure <160/90 mmHg
7. Fasting plasma glucose <126 mg/dL
8. Healthy, as determined by medical history, physical examination, standard blood chemistries (chemistry panel, complete blood clot and circulating thyroid levels) and a graded exercise stress test with monitoring of blood pressure and electrocardiogram (ECG)
9. Sedentary or recreationally active (< 3 days/wk of vigorous aerobic exercise)
10. No use of medications that might influence cardiovascular function including anti-hypertensive, lipid lowering medications, and corticosteroids
11. No use of vitamin supplements or anti-inflammatory medications, or willing to stop 1 month prior and throughout the study.

Exclusion Criteria:

1. Contraindications to:

   1. Gonadotropin releasing hormone (GnRH) antagonist
   2. Testosterone gel and aromatase inhibitor including hypersensitivity to Acyline, Androgel®, Arimidex®
   3. Extrinsic peptide hormones, mannitol, GnRH or any other GnRH analogs
2. History of or active prostate or breast cancer or other sex hormone-dependent neoplasms
3. Pre-existing or active cardiac, renal or hepatic disease
4. History of stomach ulcer or bleeding
5. History of epilepsy or other seizure disorder
6. Diabetes
7. Active infection
8. Disease that affects the nervous system
9. Abnormal resting ECG

Additionally, men participating in the gonadal suppression intervention study will do so with the understanding that they will be randomly assigned to study groups that involve either GnRH antagonist plus testosterone gel plus placebo tablet (33% chance), GnRH antagonist plus testosterone gel plus aromatase inhibitor tablet (33% chance) or GnRH antagonist plus placebo gel plus placebo tablet (33% chance).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Group 1: Acyline plus placebo (No Testosterone Add-Back); Acyline plus placebo gel and placebo tablet.	Drug: Acyline; Acyline 300ug/kg injection will be administered on Day 0 and on day 14; Other Names: Gonadotropin releasing hormone antagonist; Drug: Placebo Gel; Placebo gel packet applied daily for 28 days.; Other Names: Placebo; Drug: Placebo Tablet; Placebo oral tablet taken daily for 28 days.; Other Names: Placebo
Active Comparator: Group 2: Acyline plusTestosterone; Acyline plus transdermal testosterone gel plus placebo tablet.	Drug: Acyline; Acyline 300ug/kg injection will be administered on Day 0 and on day 14; Other Names: Gonadotropin releasing hormone antagonist; Drug: Placebo Tablet; Placebo oral tablet taken daily for 28 days.; Other Names: Placebo; Drug: Testosterone Gel; Testosterone Gel applied daily for 28 days; Other Names: Transdermal Testosterone Gel
Active Comparator: Group 3: Acyline plus Testosterone plus Arimidex); Acyline plus transdermal testosterone gel plus Aromatase inhibitor (Arimidex) oral.	Drug: Acyline; Acyline 300ug/kg injection will be administered on Day 0 and on day 14; Other Names: Gonadotropin releasing hormone antagonist; Drug: Testosterone Gel; Testosterone Gel applied daily for 28 days; Other Names: Transdermal Testosterone Gel; Drug: Arimidex; Arimidex Oral Tablet 1mg taken orally daily for 28 days; Other Names: Aromatase inhibitor

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Endothelial function	Brachial artery flow-mediated dilation, and EndoPAT™	Change from baseline at 28 days
Carotid artery compliance	Carotid artery compliance and beta stiffness index	Change from baseline at 28 days
Arterial stiffness	Pulse-wave velocity	Change from baseline at 28 days
Left ventricular diastolic function	Measured via Cardiac Echo	Change from baseline at 28 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
NADPH oxidase	Oxidative stress marker measured in endothelial cells	Change from baseline at 28 days
Nitrotyrosine	Measured in endothelial cells	Change from baseline at 28 days
MnSOD	Mitochondrial superoxide dismutase measured in endothelial cells	Change from baseline at 28 days
eNOS	Endothelial nitric oxide synthase (eNOS) measured in endothelial cell	Change from baseline at 28 days
COX IV	Marker of mitochondrial function measured in PBMCs	Change from baseline at 28 days
Mitochondrial RCR	Mitochondrial respiration measured via Oroboros O2K	Change from baseline at 28 days

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Supine blood pressure	On the cardiovascular testing days, supine blood pressure will be measured in triplicate.	Change from baseline at 28 days
Body Composition	Whole body and regional body composition will be determined using dual energy x-ray absorptiometry for subject characteristics and for the determination of fat-free mass for the AA dose preparation.	Baseline
Plasma Lipid Concentrations	Plasma lipid concentrations, including total-cholesterol (C) and triglycerides (TG) will be determined at baseline. The rationale for making these measurements is for screening criteria, subject characteristics, and because they may correlate with CV function.	Baseline
Glucose Concentrations	Fasted glucose concentrations will be measured at screening and at each vascular test.	Change from baseline at 28 days
Sex Hormones	Serum concentrations of total testosterone (T), estradiol, albumin, sex hormone binding globulin (SHBG), luteinizing hormone and follicle stimulating hormone will be measured to document changes in hormone concentrations and free T will be calculated using the known affinity constants of T for SHBG and for albumin. Additional measures of T will be measured after 60 days if testosterone has not returned to baseline. The 60 day plus measures are for safety.	Change from baseline at 28 days
Endothelin-1 (ET-1)	Plasma ET-1 will be measured because it is a potent vasoconstrictor and has complex interactions with NO. Specifically, ET-1 synthesis is under tonic inhibition by NO.	Change from baseline at 28 days
Physical Activity Levels	To document the habitual physical activity status at baseline and the last week of respective interventions, daily energy expenditure will be estimated using ActivPal monitors.	Change from baseline at 28 days

Collaborators and Investigators

• Sponsor: University of Colorado, Denver
• Collaborators: National Institute on Aging (NIA)
• Investigators: Principal Investigator: Kerrie Moreau, PhD, University of Colorado, Denver

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2016
• Primary Completion (Estimated): January 31, 2024
• Study Completion (Estimated): January 31, 2024

Study Registration Dates

• First Submitted: April 20, 2016
• First Submitted That Met QC Criteria: April 29, 2016
• First Posted (Estimated): May 2, 2016

Study Record Updates

• Last Update Posted (Actual): June 7, 2023
• Last Update Submitted That Met QC Criteria: June 5, 2023
• Last Verified: June 1, 2023

More Information

Terms related to this study

• Keywords: testosterone
• Additional Relevant MeSH Terms: Endocrine System Diseases; Gonadal Disorders; Hypogonadism; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Enzyme Inhibitors; Antineoplastic Agents; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Antineoplastic Agents, Hormonal; Steroid Synthesis Inhibitors; Estrogen Antagonists; Androgens; Anabolic Agents; Testosterone; Anastrozole; Aromatase Inhibitors; Methyltestosterone; Testosterone undecanoate; Testosterone enanthate; Testosterone 17 beta-cypionate; Acyline; Hormone Antagonists
• Other Study ID Numbers: 15-1162; R01AG049762 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO