Bone density and markers of bone remodeling in type 1 male diabetic patients

Aims: To assess the prevalence and severity of bone disease in type 1 diabetic patients and to determine serum markers of bone remodeling as well as their relationship with bone mineral density (BMD). Methods: BMD [by dual energy x-ray absorptiometry (DXA)] and serum markers of bone remodeling [osteocalcin, c-terminal telopeptide of type I collagen (CTX)], leptin and osteoprotegerin (OPG) were measured in 42 adult males with type 1 diabetes. Twenty-four nondiabetic subjects served as controls. Results: In 40% of the patients, osteopenia at the lumbar spine (L1-L4) and/or at the left hip was found, and 7% met criteria for osteoporosis. L1-L4 BMD z-score was correlated with age (r=0.365, P=0.018) and a similar trend was observed at left hip. L1-L4 BMD z-score was negatively correlated with CTX and osteocalcin (r=-0.343, P=0.028; r=-0.376, P=0.024, respectively). A significant correlation was evidenced between BMD z-score at both lumbar spine and left hip and leptin values (r=0.343, P=0.03; r=0.395, P=0.012, respectively) but after adjustment for weight this correlation was no longer significant. Osteocalcin, CTX and leptin concentrations were comparable between patients and controls, while OPG concentrations tend to be higher in diabetic subjects (P=0.08). CTX was negatively correlated with age (r=-0.390, P=0.012) and positively correlated with osteocalcin (r=0.696, P < 0.001). OPG was positively correlated with age (r=0.507, P=0.001). Conclusion: Our results suggest that in diabetic subjects osteopenia is a relatively frequent complication but bone loss is attenuated with age progression. Whether this is also mediated by OPG and/or leptin remains to be confirmed.