Bone Abstracts

Introduction: Myostatin (growth differentiation factor 8, GDF-8) has an important role in the regulation of muscle mass, and mice lacking the myostatin gene show a generalized increase in bone density and strength. Type 2 diabetes subjects have an increased risk of fragility fractures despite of higher bone mass. Taking into account the myostatin influence in bone strength a better understanding of myostatin actions in type 2 diabetes is of interest.

Objectives: Our aims were to evaluate serum myostatin concentrations in type 2 diabetes patients, and to explore its relationship with bone mineral density (BMD), bone turnover markers and fractures.

Methods: Our study was a cross-sectional one including 73 type 2 diabetes patients. Concentrations of myostatin were measured by ELISA (R&D systems). BMD was evaluated by DXA (Hologic QDR 4500).

Results: Mean age was 56±6 years and duration of diabetes was 13±7 years. Serum myostatin showed no correlation with BMD at lumbar spine (r=0.074), femoral neck (r=0.130), or total hip (r=0.174), P>0.05 for all. Moreover, there was no relationship with bone turnover markers: OC: r=0.080; BSAP: r=0.150; TRAP: r=0.027; CTX: r=0.001, P>0.05 for all. Finally, myostatin showed no differences according to the presence of prevalent fractures: fractures 2800±1309 pg/ml vs no fractures 2542±957 pg/ml, P=0.372.

Conclusion: Our data does not support an association between serum myostatin and bone parameters in type 2 diabetes. A true lack of relationship in humans may be an explanation, although a disrupted regulation of this pathway in type 2 diabetes may also take place.