Selected markers of bone turnover in type 2 diabetic patients

Abstract

The mechanisms of bone alterations in diabetes mellitus type 2 (DM2) are complex and still poorly understood. It depends on the number of protective factors on bone health, such as hyperinsulinemia, obesity, estrogens as well as factors accelerating bone resorption (e.g. hyperglycemia). The aim of this study was to evaluate the concentrations of CTx (C-terminal cross-linked telopeptide of the alpha chain of type I collagen) and OCN (osteocalcin) in DM2 patients and to look for correlations between these markers and selected clinical data as well as biochemical parameters evaluated in routine diagnostics and monitoring of diabetes (glucose, lipid profile, urea, creatinine, parathyroid hormone, HbA1c, ALT, AST and alkaline phosphatase). The study was conducted in 45 patients with type 2 diabetes aged 60.7±10.3 years. The control group consisted of 25 healthy subjects aged 57.6±11.9 years. In DM2 patients the concentrations of OCN (14.5±8.8 ng/ml; p<0.001), CTx (0.3±0.2 ng/ml; p<0.05) were significantly lower than in healthy subjects (28.1±11.9 ng/ml, 0.5±0.2 ng/ml for OCN and CTx, respectively). Significantly higher levels of OCN (p<0.05) and CTx (p<0.01) were found in women than in men within the study group. In DM2 patients OCN concentration was positive correlated with CTx ​​(r=0.721, p=0.000), PTH (r=0.426, p=0.003) and negative with TG ​​(r=-0.349, p=0.019). Furthermore, CTx was directly correlated with ALP ​​(r=0.396, p=0.009) and PTH (r=0.413, p=0.005) as well as inversely with TG (r=-0.302, p=0.044) and HbA1c (r=-0.349, p=0.019). In conclusion, the observed lower levels of OCN and CTx and their positive inter-correlation may suggest overall slowed down bone metabolism with reduced bone formation and bone resorption in patients with DM2.