High bone turnover is associated with accelerated bone loss but not with increased fracture risk in men aged 50 and over: the prospective MINOS study.

OBJECTIVES: The association of bone turnover markers (BTM) with bone loss and fracture risk in men is poorly studied. The morphological basis of such a relationship is unknown. The objective of this study was to evaluate the association between baseline BTM levels and subsequent bone loss and fracture risk in men.
METHODS: This study is a prospective 7.5-year follow-up of the cohort composed of 723 men aged 50-85 years. Serum concentrations of osteocalcin, bone alkaline phosphatase (BAP), procollagen type I N-terminal propeptide, C-terminal telopeptide of type I collagen (beta-CTX-I) and urinary excretion of deoxypyridinoline and beta-CTX-I were measured at baseline. Every 18 months, incident fractures were recorded and bone mineral density (BMD) was measured by dual energy x ray absorptiometry DXA (spine, hip, distal forearm, whole body).
RESULTS: Increase in BTM levels was associated with faster bone loss at the level of the trochanter, whole body and distal forearm. At the level of the distal radius and the ulna, increase in the serum BAP and beta-CTX-I levels were associated with faster apparent, net and estimated endosteal bone mineral loss. BTM levels did not correlate with the periosteal expansion rate. BTMs were significantly associated with bone mineral loss but their predictive power was poor. BTMs did not predict incident fractures.
CONCLUSIONS: In men aged 50 and over, accelerated bone turnover is associated with greater endosteal bone mineral loss. From a practical point of view, BTMs cannot be used for the prediction of accelerated bone loss or fractures in the clinical management of osteoporosis in men.