This study is NOT currently recruiting participants.
Number
11-CH-0078
Sponsoring Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Recruitment Detail
Type: Completed Study; data analyses ongoing Gender: Male Min Age: 18 Years Max Age: 30 Years
Referral Letter Required
No
Population Exclusion(s)
Female;Children
Keywords
Cortisol; ACTH; Exercise
Recruitment Keyword(s)
None
Condition(s)
Healthy Volunteers
Investigational Drug(s)
Mifepristone
Investigational Device(s)
Intervention(s)
Drug: Mifepristone Drug: Placebo Drug: Spironolactone Drug: Dexamethasone
Supporting Site
National Institute of Diabetes and Digestive and Kidney Diseases
- The adrenal glands, located above the kidneys, produce hormones called glucocorticoids and mineralocorticoids. Glucocorticoids, especially the hormone cortisol, act on nearly all cells in the body with effects that are especially important to the body's stress response. They maintain heart function, blood pressure, and proper blood sugar levels, and help regulate the body's responses to infections and injury. Mineralocorticoids help to regulate salt and water levels in the body.
- Blood levels of cortisol have a natural day-to-night pattern: the highest levels occur in the morning and the lowest levels occur at night. This pattern is regulated by the hormone ACTH, which is made by the pituitary gland, and causes increased or decreased cortisol levels in response to the levels in the blood. Research has shown that older men have higher ACTH and cortisol levels than younger men, and that endurance-trained athletes have different cortisol levels than more sedentary individuals. Researchers are interested in studying these differences in cortisol levels and their potential effects on health.
Objectives:
- To compare cortisol levels and responses in sedentary young men and endurance-trained male athletes and elderly men.
Eligibility:
- Healthy men between 18 and 30 years of age who have exercised less than 1 hour each week for the past 3 years.
- Healthy men between 18 and 30 years of age who have regularly run more than 45 km (28 miles) per week for at least 3 months.
- Healthy men between 65 and 80 years of age who have exercised less than 1 hour each week for the past 3 years.
Design:
- Participants will be screened with a full medical history and physical examination, as well as blood and urine samples.
- Participants will collect saliva and urine samples at home, both for cortisol measurements. Saliva samples should be collected in the evening on 2 separate days, and urine samples should be collected continuously for 12-hour intervals (7 AM to 7 PM and 7 PM to 7 AM) over a single 24-hour period. Participants will provide baseline blood samples at the National Institutes of Health when they drop off the saliva and urine samples.
- Participants will have four separate evening/overnight tests at the National Institutes of Health. At these tests, participants will take study drugs or a look-alike capsule to block the effects of only glucocorticoid, only mineralocorticoid, both glucocorticoid and mineralocorticoid, or neither. Blood, saliva, and urine samples will be collected regularly from 7 PM to 7 AM the next morning.
- Participants will have a final clinic test in which they will take dexamethasone late in the evening (11 PM to midnight) and visit the National Institutes of Health by 8 AM the next morning to provide a blood sample.
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INCLUSION CRITERIA: Men aged 18 to 30 years of age are required for the young endurance trained and sedentary groups; men aged 65-80 years for the older study group, who will meet criteria for sedentary men below. Women and children are excluded to enhance homogeneity of responses and avoid the influence of menstrual cyclicity on the HPA axis. Sedentary: -Less than one hour physical activity per week for three years -No change in exercise anticipated for 6 weeks Trained: -Greater than 45km (28 miles) running per week for at least 3 months -No change in exercise anticipated for 6 weeks For all participants: -All races -Sleep-wake cycle with sleeping at night, wakening between 5 and 8 AM -BMI between 18 and 25 kg/M2 -Normal TSH and free T4 EXCLUSION CRITERIA: For all participants: -Sleep disorders as assessed by sleep apnea questionnaire -Smoking -No more than 2 servings of alcohol daily -Medications known to affect the HPA axis or steroid metabolism, including narcotics, Glucocorticoids, megace or CYP3A4 modulators -History of psychiatric or endocrine disorders -Marijuana or other illicit drug use -Recent appendicular or skeletal injury -Uncontrolled hypertension -Chronic pain requiring daily medication -Current treatment with medications related to mineralocorticoid function such as potassium, ACE-inhibitors, ARBs, diuretics, spironolactone -Frailty score of 4-7 on the Canadian Study of Health and Aging frailty scale (Rockman 2005) -Overtraining syndrome will be an exclusion and will be assessed by questionnaire -Abnormal creatinine level (greater than 1.2 mg/dl) -Liver function tests greater than two fold normal -Benzodiazepine use
Men aged 18 to 30 years of age are required for the young endurance trained and sedentary groups; men aged 65-80 years for the older study group, who will meet criteria for sedentary men below. Women and children are excluded to enhance homogeneity of responses and avoid the influence of menstrual cyclicity on the HPA axis.
Sedentary:
-Less than one hour physical activity per week for three years
-No change in exercise anticipated for 6 weeks
Trained:
-Greater than 45km (28 miles) running per week for at least 3 months
For all participants:
-All races
-Sleep-wake cycle with sleeping at night, wakening between 5 and 8 AM
-BMI between 18 and 25 kg/M2
-Normal TSH and free T4
EXCLUSION CRITERIA:
-Sleep disorders as assessed by sleep apnea questionnaire
-Smoking
-No more than 2 servings of alcohol daily
-Medications known to affect the HPA axis or steroid metabolism, including narcotics, Glucocorticoids, megace or CYP3A4 modulators
-History of psychiatric or endocrine disorders
-Marijuana or other illicit drug use
-Recent appendicular or skeletal injury
-Uncontrolled hypertension
-Chronic pain requiring daily medication
-Current treatment with medications related to mineralocorticoid function such as potassium, ACE-inhibitors, ARBs, diuretics, spironolactone
-Frailty score of 4-7 on the Canadian Study of Health and Aging frailty scale (Rockman 2005)
-Overtraining syndrome will be an exclusion and will be assessed by questionnaire
-Abnormal creatinine level (greater than 1.2 mg/dl)
-Liver function tests greater than two fold normal
-Benzodiazepine use
Principal Investigator
Referral Contact
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