Bone remodeling in men with type 2 diabetes: is it just the same thing as in women?

Background and aim: The mechanisms of reducing the bone mineral density (BMD) in men with type 2 diabetes are poorly understood. The aim of our study was to determine the relationships between the markers of bone remodeling and BMD in men with type 2 diabetes.Materials and Methods: The study included 59 men with type 2 diabetes, from 50 to 75 years of age. BMD and T-score were determined by dual-energy X-ray absorptiometry. A serum levels of parathyroid hormone (PTH), free testosterone, osteocalcin, osteoprotegerin, sclerostin, and urinary excretion of C-terminal telopeptides of type I collagen (CTX-I) were determined by ELISA. Control group comprised of 21 healthy subjects with normal BMD, matched by sex and age.Results: A reduced BMD was revealed in 29 patients, including 4 individuals with osteoporosis and 25 subjects with osteopenia. The levels of osteocalcin were decreased and the levels of osteoprotegerin and sclerostin were increased in observed diabetic subjects as compared to control (p=0.02, p<; 0.001 and p=0.02 respectively). The excretion of CTX-1 was reduced in patients with diabetes (p<; 0.001). There were no differences in PTH and free testosterone concentrations between control and diabetic subjects. In stepwise multivariate regression analysis, sclerostin was the most significant predictor for lumbar spine T-score (β=0.496, R
²
=0.23, p=0.00007), the level of PTH influenced the femoral neck T-score (β=-0.29, R
²
=0.26, p=0.005).Conclusions: The obtained results suggest that the bone remodeling in men with type 2 diabetes is reduced due to the inhibition of osteoblastogenesis and decrease in the bone formation and resorption. Therefore, the mechanisms of osteoporosis in men with type 2 diabetes may be different from those in postmenopausal diabetic women.