In the context of male osteoporosis, we hypothesize that regional changes in trabecular bone, as well as changes in cortical porosity will play a major role, and thus also affect bone strength. In developing therapeutics the response of individual compartments, regional variations post-therapy will have considerable impact on selecting the therapies as well as monitoring response to therapy. This study, a precursor to other therapeutic trials, will lay the ground-work for the future.

We will recruit 80 subjects who will be stratified into groups based on their T-scores. All subjects will be imaged at Baseline and 12 months. Measures of bone micro-architecture in the tibia and radius using peripheral computed tomography, bone strength measures through finite element analysis will be obtained at all time points. DXA measures at the spine, femur and forearm will be obtained as reference measures. In addition whole body DXA scans will be performed for assessment of body composition.

Inclusion Criteria:

1. Men 50-85 years old
2. Patients must be willing to undergo a DXA scan.
3. Patients should be willing to undergo HRpQCT scan of the radius and tibia.

Exclusion Criteria:

1. Inability to tolerate CT scans

2. Use of medications known to impact bone and mineral metabolism:

   • use of a bisphosphonate or teriparatide in the last year or for >12 months ever;
   • current calcitonin;
   • prednisone >5 mg daily or the equivalent glucocorticoid for >10 days in the last 3 months;
   • current testosterone therapy;
   • current thiazolidinedione (TZD);
   • current androgen deprivation therapy;
   • current use of an antiepileptic agent that alters hepatic vitamin D clearance;
   • use of thyroid hormone replacement with current thyroid stimulating hormone <0.1 mIU/L

3. Disease known to affect bone (e.g., primary hyperparathyroidism, Pagets disease, clinically significant liver disease)

4. Illicit drug use or alcohol use >3 drinks/day

5. Serum calcium >10.2 mg/dL or calculated creatinine clearance <30 mL/min

6. Weight >350 pounds (the maximum weight limit of the DXA)

7. Hardware in the lumbar spine

8. History of bilateral hip replacement, or bilateral wrist or ankle fracture

Community UCSF VA Medical Center