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

Mayo Clinic

Status and phase: Completed; Phase 1

Conditions: Healthy

Treatments: Drug: Saline; Other: Fasting procedure; Other: Exercise; Drug: Hyperglycemia; Procedure: Blood Draws

Study type: Interventional

Funder types: Other

Identifiers

NCT01800370

12-007753

Details and patient eligibility

About

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.

Enrollment: 40 patients

Sex: Male

Ages: 18 to 80 years old

Volunteers: Accepts Healthy Volunteers

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.

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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40 participants in 3 patient groups, including a placebo group

Hyperglycemia

Experimental group

Description:

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.

Treatment:

Drug: Hyperglycemia

Procedure: Blood Draws

Other: Fasting procedure

Saline

Placebo Comparator group

Description:

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.

Treatment:

Procedure: Blood Draws

Drug: Saline

Other: Fasting procedure

Exercise

Experimental group

Description:

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.

Treatment:

Procedure: Blood Draws

Other: Fasting procedure

Other: Exercise