HORMA: Hormonal Regulators of Muscle and Metabolism in Aging

Inclusion Criteria: Men who are 65-90 years of age Total serum IGF-1 (insulin-like growth factor) in the lower tertile for adults (56-167 ug/dl) Total serum testosterone of 150-550 ng/dL Exclusion Criteria: BMI (Body Mass Index) 35 kg/m2 or greater Weight instability (>3% change in prior 3 months) Daily intake of total kilocalories less than or equal to 0.8X the RDA and intake of protein between 0.8 and 1.4 g/kg/day inclusive Acute illness in the prior 30 days Resistance training (wt lifting) in the past 12 months Vigorous aerobic sports (Competing as a Master athlete in the prior 5 years; weekly swimming, racquet ball, cycling, tennis, in preceding 12 months) Use of an anabolic agent (androgen, androgen precursor, rhGH, etc) in the preceding 12 months Use of medications that might affect amino acid metabolism (e.g. beta-adrenergic blockers, beta-agonists, Ca2+ channel blockers, corticosteroids) Fasting sugar greater than or equal to 126 mg/dl or diabetes requiring Rx History of benign intracranial hypertension Heart failure, active angina, or myocardial infarction in the prior 6 months or history of aortic stenosis Uncontrolled hypothyroidism or hyperthyroidism Rheumatoid arthritis, cirrhosis or active hepatitis History of carpal tunnel syndrome Prior cancer other than squamous or basal cell carcinoma of the skin Sleep apnea or severe chronic lung disease Anticoagulation with heparin or coumadin Blood pressure not controlled with medication to <180/95 mm Hg Calculated creatinine clearance <50 cc/min Serum prostatic antigen >4.0 or American Urological Association score greater than or equal to 8 Hematocrit greater than or equal 52%, or ALT >1.5X ULN Failure to pass a modified Bruce treadmill stress test Severe disability limiting strength or physical function testing Dementia or cognitive impairment affecting a subject's ability to provide informed consent