Physiological and Psychological Effects of Testosterone During Severe Energy Deficit and Recovery

Study Overview
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Brief Summary
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The objective of this study is to determine whether maintaining a eugonadal state, during severe, sustained energy deficit, attenuates physiological decrements, particularly the loss of lean body mass.

Detailed Description
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This study will enroll up to 60 physically active men in a 3-phase randomized, placebo-controlled trial. After completing a 14-day (free-living, phase 1), energy-adequate, diet-acclimation phase (protein, 1.6 g∙kg-1∙d-1; fat 30% total energy intake, with remaining energy derived from carbohydrate), participants will be randomized to one of two experimental groups and undergo a 28-day (live-in, phase 2), 55% energy deficit phase: energy deficit alone (DEF) or energy deficit + exogenous testosterone (DEF+TEST). Recovery (free-living, phase 3) will be assessed after completing phase 2 to determine when body mass has been recovered within ± 2.5% of initial body mass (duration will vary, 42-day maximum for phase 3). This study will delineate the contribution of testosterone declines from the physical and mental demands encountered by Warfighters during military training and combat operations on complex markers of physiological and psychological status, addressing a direct, consistently observed, gap in knowledge.

Official Title
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Physiological and Psychological Effects of Testosterone During Severe Energy Deficit and Recovery: a Randomized, Placebo Controlled Trial

Conditions
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Caloric Restriction, Exercise

Intervention / Treatment
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* Drug: Sesame Oil
* Drug: testosterone enanthate


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Physically active (at least 2 days per week aerobic and/or resistance exercise) Not taking any prescription medications and/or willing to refrain from all medication use prior to and throughout the entire study period, unless provided/approved by the study physician Willing to refrain from alcohol, smoking, e-cigarettes, or use of any nicotine product, caffeine, and dietary supplement use throughout the entire study period At the discretion of the study physician, wash-out period for medications, supplements, and over-the-counter medications is ≥ 1 to 4 weeks Wash-out period for caffeine and alcohol is ≥ 7 days Willing to live on the Pennington Biomedical Research Center inpatient unit for 28 consecutive days Willing to have a urine drug screening Meets age-specific U.S. Army body composition standards according to Army Regulation 600-9, which includes estimates of percent body fat based on height, weight, and circumference measures (neck and waist) Total testosterone concentration is within the normal physiological range, total testosterone (300-1,000 ng/dL). Exclusion Criteria: Musculoskeletal injuries that compromise exercise capability Diagnosed cardiometabolic disorders (i.e., hypertension, hyperlipidemia, kidney disease, diabetes, etc.) Allergies or intolerance to foods, vegetarian practices, or history of complications with lidocaine Anabolic steroid, human growth hormone, or nutritional testosterone precursor-like supplement use within the past 6 months Will not refrain from smoking (any nicotine product), alcohol, caffeine, or any other dietary supplement during the study Any use of antibiotics, except topical antibiotics, within 3 months of study participation Colonoscopy within 3 months of study participation Chronic use of laxatives, stool softeners, antacids, or anti-diarrheal medications (≥ once a week) History of gastrointestinal disease (e.g., celiac, irritable bowel syndrome, colitis, Crohn's disease) Restrained eater (the Three-Factor Eating Questionnaire) as assessed by the study's psychological and behavioral assessment staff Adults unable to consent Women Prisoners Metal implants, claustrophobia, head size incompatible with MRI equipment, etc. Sedentary or engages in <2 days of physical activity per week (aerobic and/or resistance training) Exceeds age-specific U.S. Army body composition standards according to Army Regulation 600-9 Previous history of kidney stones unless otherwise approved by the medical investigator Systolic blood pressure > 150 or diastolic blood pressure > 95 mmHg Previous history of breast or prostate cancer Previous history of Chronic Obstructive Pulmonary Disease or Obstructive Sleep Apnea Findings of lab results of prostate-specific antigen > 3ng/ml, Hematocrit > 50%, or positive urine drug screening Based on the investigative team's clinical judgment, a subject may not be appropriate for participation in the study

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 39 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Energy Deficit<br>Participants randomly assigned to the control condition will be subject to exercise-induced energy expenditure resulting in a 55% energy deficit and will be administered sesame oil placebo injections during phase 2 of the trial. | Drug: Sesame Oil<br>* 200 mg sesame oil by intramuscular injection weekly on days 15, 21, 28, and 35<br>|
| Experimental: Energy Deficit + Testosterone<br>Participants randomly assigned to the intervention condition will be subject to exercise-induced energy expenditure resulting in a 55% energy deficit and will be administered testosterone enanthate injections during phase 2 of the trial. | Drug: testosterone enanthate<br>* 200 mg testosterone enanthate by intramuscular injection weekly on days 15, 21, 28, and 35<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Body Composition at the End of Each Study Phase | Height was measured using a stadiometer. Weight was measured using a calibrated digital scale. Body composition was determined using dual-energy X-ray absorptiometry. These data were used to calculate fat-free body mass, fat mass, and total body tissue mass. | end of each study phase: Day 11 for Phase 1, Day 39 for Phase 2, up to Day 85 for Phase 3 |