Bone Abstracts

Denosumab (DNMB) is an effective treatment for osteoporosis with antiresorptive effect that has demonstrated to increase the bone mass and reduces the incidence of both vertebral and nonvertebral fractures in randomized controlled trials (RCTs).

Objectives: To confirm that this drug is actually effective in our experience into daily clinical practice as well.

Material and methods: 30 postmenopausal women, mean age 71 years (r=41–89), were treated with DNMB (60 mg Q6M) during 1 year. Calcium, phosphorus, and BTM of formation (P1NP) and resorption (CTX) were measured in serum at baseline, 6 months and 12 months by the following techniques: CTX by electrochemisluminescence and PINP by RIA. BMD were measured by DXA (Hologic c.v. in vivo 1.2%) at the lumbar spine (LS), femoral neck (FN), total hip (TH), and forearm at baseline and 12 months.

Results: DNMB did not produce significant variations in serum calcium and phosphorus. BTM decreased very significantly (P<0.001): CTX decreased 66% at 6 months and 65.9% at 12 months. P1NP decreased 55.11% at 6 and 44.9% at 12 months. BMD increased in LS 5% (P<0.001), TH 2.36% (P<0.001) and forearm 2.18% (P<0.01). BMD in FN also increased (1.57%) but was not statistically significant. There were not differences in BMD responses related with the use of previous antiosteoporotic treatments although the BTM were a different magnitudes in their decrease along the time. We found a correlation between changes in CTX and the gain in BMD at the level of CL, we did not found any other correlation between changes in BTM and the BMD in other localizations.

Conclusion: One year of treatment with DNMB causes a very significant decrease in the bone resorption and bone formation markers. DNMB produced a significant increase of the bone mass at LS, TH and forearm. The changes in BTM occurred just after 6 months of treatment with DNMB and changes in CTX are associated to progressive increasing of BMD in LS. Thus, we suggest that changes in CTX can be used as precocious indicators for the BMD later response after DNMB treatment