OBJECTIVES:

I. Determine the effect of human parathyroid hormone (1-34) on bone mass in middle-aged men with idiopathic osteoporosis.

PROTOCOL OUTLINE: This is a randomized, double blind, placebo controlled study. All patients self-administer daily subcutaneous injections of human parathyroid hormone (1-34) or placebo for a period of 2.5 years.

Patients are followed regularly for unacceptable toxicities.

PROTOCOL ENTRY CRITERIA:

--Disease Characteristics--

Osteoporosis as defined by: Bone mineral density at the lumbar spine or femoral neck that is 2.5 standard deviations below peak bone mass reference value (T score less than -2.5)

No family history of male osteoporosis

No other metabolic bone disease

--Prior/Concurrent Therapy--

Endocrine therapy:

• No concurrent glucocorticoid therapy
• No prior steroid use

Surgery: No prior gastrointestinal tract surgery

Other: No prior or concurrent anticonvulsant therapy

--Patient Characteristics--

Hematopoietic: Normal CBC

Hepatic: Normal liver function

Renal: Normal renal function

Other:

• Normal thyroid function
• Normal adrenal function
• Normal gonadal status
• No myeloma or other malignancy
• No alcoholism, hypercortisolism or diabetes mellitus
• No gastrointestinal tract disease or disorder associated with malabsorption