The Effect of Mixed Exercise and Metabolic Stress in Relationship to Age in Healthy Men

Study Overview
=================
Brief Summary
-----------------
Aging in men reduces the amount of luteinizing hormone (LH) and testosterone (Te) secreted in each burst. Stress-associated mechanisms introduced by acute illness and chronic disease decrease LH and Te secretion further. A major unresolved issue is whether the aging process heightens the negative effects of a stressor (whether physical or metabolic) upon LH and Te secretion. This study will assess LH and Te secretion in response to a physical stressor (maximal exercise) and a common metabolic stressor (hyperglycemia) as a function of age in healthy men ages 18-80 yr.

Official Title
-----------------
The Effect of Mixed Exercise and Metabolic Stress Upon Pituitary Secretion in Relationship to Age in Healthy Men: a Pilot Study

Conditions
-----------------
Healthy

Intervention / Treatment
-----------------
* Drug: Hyperglycemia
* Drug: Saline
* Other: Exercise
* Procedure: Blood Draws
* Other: Fasting procedure


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Community dwelling, healthy men age 18 to 80 Body-Mass Index (BMI) 18-30 kg/m2 Willingness to provide written informed consent Physician acceptable screening ECG for participants 60 years and older Exclusion Criteria: recent use of psychotropic or neuroactive drugs (within five biological half-live) obesity (outside weight range above) acute weight change (loss or gain of >2 kg in 6 weeks Laboratory test results not deemed physician acceptable triglycerides > 300 BUN >30 creatinine > 1.5 mg/dL liver functions tests twice upper limit of normal electrolyte abnormality anemia; hemoglobin < 12.0 gm/dL drug or alcohol abuse psychosis, depression, mania or severe anxiety acute or chronic organ-system disease endocrinopathy, other than primary thyroidal failure receiving replacement untreated osteoporosis nightshift work or recent transmeridian travel (exceeding 3 time zones within 7 days of admission) PSA > 4.0 ng/mL, History or suspicion of prostatic disease (elevated PSA,indeterminate nodule or mass, obstructive uropathy) History of carcinoma (excluding localized basal cell carcinoma removed or surgically treated with no recurrence History of thrombotic arterial disease (stroke, TIA, MI, angina) or deep vein thrombophlebitis History of CHF, cardiac arrhythmias, congential QT prolongation, and medications used to treat cardiac arrhythmias Gynecomastia > 2 cm, untreated Untreated gallbladder disease History of smoking greater than one ppd.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
-----------------
Male

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Hyperglycemia<br>Hyperglycemia (rest controlled) will be induced by i.v. injection of 25 mL of dextrose 50% over 3 minutes with the subject supine. Includes blood draws and fasting requirements. | Drug: Hyperglycemia<br>* Hyperglycemia (rest controlled) will be induced by i.v. injection of 25 mL of dextrose 50% over 3 minutes with the subject supine.<br>Procedure: Blood Draws<br>* Blood will be sampled every 10 min from 0700 to 1300 h. Each intervention will begin at 0800 h after 1 h of baseline sampling, and be completed by 0900 h. Intervention is followed by 4 additional h of sampling to capture recovery (total sampling 6 h). Ten-min samples are for Te, LH, ACTH, cortisol, and GH. Glucose will be checked every 30 min. At 07000 h an archival serum sample will be obtained for safety-monitoring purposes.<br>Other: Fasting procedure<br>* Beginning at 1900 h on the evening prior to each study visit, subjects will remain fasting except for water, diet soda, and other non-caloric and non-caffeinated fluids, until 1300 h the next day.<br>|
| Placebo Comparator: Saline<br>Saline (rest controlled) will be induced by i.v. injection of 25 mL of saline over 3 minutes with the subject supine. Includes blood draws and fasting requirements. | Drug: Saline<br>* Saline (rest controlled) will be induced by i.v. injection of 25 mL of saline over 3 minutes with the subject supine.<br>Procedure: Blood Draws<br>* Blood will be sampled every 10 min from 0700 to 1300 h. Each intervention will begin at 0800 h after 1 h of baseline sampling, and be completed by 0900 h. Intervention is followed by 4 additional h of sampling to capture recovery (total sampling 6 h). Ten-min samples are for Te, LH, ACTH, cortisol, and GH. Glucose will be checked every 30 min. At 07000 h an archival serum sample will be obtained for safety-monitoring purposes.<br>Other: Fasting procedure<br>* Beginning at 1900 h on the evening prior to each study visit, subjects will remain fasting except for water, diet soda, and other non-caloric and non-caffeinated fluids, until 1300 h the next day.<br>|
| Experimental: Exercise<br>Monitored exercise of 7-minute biking, 2-minute arm weights and a blood draw at the 10-minute time point will be repeated 3 times,which takes 30 minutes. Bilateral arm curls begin at 20 pounds and decrease by 5 pounds as needed to sustain 2 minutes of exercise at a rate of 1 complete curl every 2 seconds. Includes blood draws and fasting requirements. | Other: Exercise<br>* Monitored exercise of 7-minute biking, 2-minute arm weights and a blood draw at the 10-minute time point will be repeated 3 times,which takes 30 minutes. Bilateral arm curls begin at 20 pounds and decrease by 5 pounds as needed to sustain 2 minutes of exercise at a rate of 1 complete curl every 2 seconds.<br>Procedure: Blood Draws<br>* Blood will be sampled every 10 min from 0700 to 1300 h. Each intervention will begin at 0800 h after 1 h of baseline sampling, and be completed by 0900 h. Intervention is followed by 4 additional h of sampling to capture recovery (total sampling 6 h). Ten-min samples are for Te, LH, ACTH, cortisol, and GH. Glucose will be checked every 30 min. At 07000 h an archival serum sample will be obtained for safety-monitoring purposes.<br>Other: Fasting procedure<br>* Beginning at 1900 h on the evening prior to each study visit, subjects will remain fasting except for water, diet soda, and other non-caloric and non-caffeinated fluids, until 1300 h the next day.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Testosterone concentration after 30 minutes of exercise | During the exercise visit subjects will perform an exercise test on a bike and lift weights with both arms for a total of 30 minutes. | 30 minutes after initiating exercise | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Male, Healthy