Lower serum osteocalcin concentrations in patients with type 2 diabetes and relationships with vascular risk factors among patients with coronary artery disease

Background

Lower serum concentrations of the osteoblast-derived protein, osteocalcin, have been associated with poorer glycemic control, insulin resistance and atherosclerosis, and with the development of type 2 diabetes (T2DM).

Methods

This study compares concentrations of two physiological forms of osteocalcin, carboxylated (cOCN) and uncarboxylated (unOCN), between participants with T2DM (n?=?20) and age-, gender- and body mass index (BMI)-matched participants without T2DM (n?=?40) among patients with coronary artery disease (CAD), and it explores relationships between osteocalcin concentrations and cardiovascular risk factors.

Results

Concentrations of unOCN (2.71?±?1.86 vs. 4.70?±?2.03?ng/mL; t?=??3.635, p?=?0.001) and cOCN (8.70?±?2.27 vs. 10.77?±?3.69?ng/mL; t?=??2.30, p?=?0.025) were lower in participants with T2DM. In participants without T2DM, concentrations of cOCN were associated with fitness (VO_2Peak rho?=?0.317, p?=?0.047) and lower body fat (rho?=??0.324, p?=?0.041). In participants with T2DM, lower unOCN was associated with HbA1c (rho?=??0.516, p?=?0.020). Higher body mass was associated with higher unOCN (rho?=?0.423, p?=?0.009) in participants without T2DM, but with lower concentrations of both unOCN (rho?=??0.590, p?=?0.006) and cOCN (rho?=??0.632, p?=?0.003) in participants with T2DM.

Conclusion

In patients with CAD, lower osteocalcin concentrations were related to type 2 diabetes, and to adverse fitness, metabolic and obesity profiles.