Correlation between serum N-terminal mid-fragment of osteocalcin and index of glucose metabolism after fracture

  Objective  To investigate the relationships between serum N-terminal mid-fragment of osteocalcin (N-MID OC) and hemoglobin A1c(HbA1c), fasting plasma glucose(FPG), fasting insulin (FINS) and C-peptide (C-P).

  Methods  A total of 196 male patients with single closed fracture were included in fracture group and 64 healthy men in healthy control group based on a retrospective study method, and the general data and biochemical indexes of the two groups were compared. The fracture patients were divided into four subgroups according to N-MID OC quartile, and the levels of HbA1c, FPG, FINS and C-P in four groups were compared. The correlations of serum N-Mid OC level with glucose metabolism and biochemical indexes were analyzed.

  Results  There were no differences in age, body mass index, serum creatinine and HbA1c between the fracture group and the healthy control group (P>0.05). Leukocyte, alanine aminotransferase, aspartate aminotransferase, FPG, FINS, C-P in the fracture group were higher than those in the healthy control group, while platelets, hemoglobin, calcium ions, the levels of 25-hydroxyvitamin D₃ and N-MID OC levels were lower than those of the healthy control group (P < 0.05). There were significant differences in age, platelets, FPG, and N-MID OC in the subgroups (P < 0.05). Correlation analysis showed that serum N-MID OC was negatively correlated with age (r=-0.280, P < 0.001), HbA1c(r=-0.081, P=0.011) and FPG(r=-0.196, P=0.006). After adjusting for age factor, multiple linear regression analysis showed that FPG was an independent factor affecting serum N-MID OC of patients with single closed fracture(β=-0.147, P < 0.001, 95%CI, -0.663 to -0.023).

  Conclusion  There is a correlation between glucose metabolism and serum N-MID OC after fracture, which may be a factor affecting bone metabolism.