Bone, testosterone and glucose metabolism.

Rationale:

Osteoporosis is a common disease that is characterized by low bone mass with microarchitectural disruption and skeletal fragility, resulting in increased risk of fracture. Normally, bone quality is maintained by a dynamic process, known as bone remodeling. Animal research shows that osteocalcin, secreted by osteoblasts, acts as a hormone and influences the male gonal axis and insuline sensitivity.



Objective of the study:

The objective of the study is to study the relationship between undercarboxylated osteocalcin levels, testosterone concentrations, glucose tolerance and insulin sensitivity in male subjects with primary osteoporosis.



Study design:

Open label randomized controlled cross-over trial.



Study population:

Male objects with recently diagnosed primary osteoporosis.



Intervention:

The participants will be randomized to two treatment groups (Teriparatide 12 weeks or no treatment 12 weeks), in a cross-over design.



Main study parameters/endpoints:

1. Undercarboxylated osteocalcin;

2. Testosterone concentrations;

3. Glucose tolerance;

4. Insulin sensitivity.

The hypothesis is that bone influences the male gondal axis and insuline sensitivity.

Baseline, 6 weeks, 12 weeks, 18 weeks, 24 weeks.

The participants will receive Teriparatide treatment for 12 weeks and no treatment for 12 weeks in a crossover design.

After finishing both interventions (t=12 weeks and t=24 weeks) patients will undergo an oral glucose tolerance test and a hyperinsulinemic euglycemic clamp, and whole body dual-energy X-ray absorptiometry (DXA scan).