Insulin Sensitivity in Men With the Metabolic Syndrome

• Status: Suspended
• Trial end date: 2011-03-01
• Target enrollment: 0
• Participant gender: Male

Summary

The metabolic syndrome is a medical condition defined by high levels of cholesterol in the blood, high blood pressure, central obesity (gain in fat around the region of the stomach), and insulin resistance (body responds less well to insulin). This state of impaired insulin resistance can lead to type 2 diabetes mellitus, which is one of the most common metabolic disorders in the U.S. Numerous studies have shown an inverse relationship between insulin resistance and testosterone levels in men, however, causality has not been established. This protocol investigates the role of testosterone in modulating insulin sensitivity in insulin resistant states such as the metabolic syndrome. The hypothesis is that testosterone administration will improve insulin sensitivity.

• Phase: N/A
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
• Collaborator: American Diabetes Association
• Treatments: Anastrozole; Goserelin; Insulin; Insulin, Globin Zinc; Methyltestosterone; Testosterone; Testosterone 17 beta-cypionate; Testosterone enanthate; Testosterone undecanoate

Criteria

Inclusion Criteria:

• Age 50-75 yr

• Diagnosis of the metabolic syndrome defined by the American Heart Association/National Heart, Lung, and Blood Institute guidelines as the presence of three or more of the following:

• Waist circumference > 102 cm

• Serum triglycerides > 150 mg/dL

• HDL cholesterol < 40 mg/dL

• Blood pressure > 130 mm Hg systolic or 85 mm Hg diastolic, or treatment with anti-hypertensives

• Fasting serum glucose > 100 mg/dL

• Plasma total testosterone level less than 300 ng/dL (1 SD below the mean for young healthy men)

• Stable weight for previous three months (no weight change greater than or equal to +/-10 lbs)

• Normal TSH, prolactin and prostate specific antigen (PSA) levels (<2.5 ng/mL)

Exclusion Criteria:

• New diagnosis of type 2 diabetes as defined by the ADA criteria: fasting glucose greater than 126 mg/dL or random blood glucose greater than 200 mg/dL on two occasions, or on oral hypoglycemic agents

• Contraindication to stress testing

• Contraindication to MRI scanning (Central nervous system aneurysm clips; Implanted neural stimulator; Implanted cardiac pacemaker or defibrillator; Cochlear implant; Ocular foreign body (e.g. metal shavings); Insulin pump; Metal shrapnel or bullet)

• History of testicular disorders (i.e. cryptorchidism)

• History of bleeding disorders (i.e. thrombocytopenia) or baseline hemoglobin levels less than 12g/dL

• History of metabolic bone disease (osteoporosis, osteomalacia)

• History of prostate cancer

• History of sleep apnea (subjects will also be excluded if at their baseline assessment they admit to heavy snoring, restless sleep, and/or excessive daytime somnolence)

• Symptoms of urinary outflow obstruction (i.e. benign prostatic hypertrophy)

• Illicit drug use or heavy alcohol use (>4 drinks/day)

• Allergic disorders

• Current medications (must exclude individuals taking the following medications):

• Testosterone,

• Cimetidine,

• Spironolactone,

• Ketoconazole,

• Finasteride,

• DHEA,

• Androstenedione,

• Oral steroids,

• GnRH analogs