Markers of bone metabolism in patients with type 2 diabetes mellitus

There are only a few reports on bone metabolism in type 2 diabetes. Impaired bone turnover in type 2 diabetes appears to result from decreased bone formation. Some studies suggest that poor glycaemic control in type 2 diabetes may contribute to osteopaenia. The aim of our study was to investigate biochemical markers of bone turnover in patients with type 2 diabetes, In our study 51 type 2 diabetes mellitus patients and 30 healthy persons were enrolled. 30 of the patients had macrovascular complications and 19 of them had microangiopathies. The mean age of the patients was 62.3 (9.3) years and the mean disease duration was 11.1 (7.0) years. Serum crosslaps (C-telopeptide, CIx), parathyroid hormone (PTH), calcium, inorganic phosphate, glucose, HbAlc, alkaline phosphatase and creatinine were measured. No differences between patients and controls were observed in serum PTH concentration and alkaline phosphatase activity. Patients had lower serum levels of CTX than controls [0.309 (0.277) vs 0.396 (0.196), p< 0.05]. In turn, serum levels of calcium and inorganic phosphates were higher in diabetic patients in comparison to the control group. We found a significant statistical correlation between CTx levels and PTH (r=0.48. p< 0.05). We also noticed a positive relationship between CTX, PTH and creatinine concentration. Our study suggests that decreased serum CTX levels in type 2 diabetes mellitus patients may be an effect of altered equilibrium in bone formation and resorption processes. A significant correlation between PTH and CTX and creatinine concentration indicate that renal function in diabetes patients may affect serum levels of bone metabolism markers.