Bone turnover predicts change in volumetric bone density and bone geometry at the radius in men.

ABSTRACT

Peripheral quantitative computed tomography scans of the distal and midshaft radius were performed in 514 European men aged 40-79 years at baseline and a median of 4.3 years later. Age-related changes in volumetric bone mineral density (vBMD) and bone geometry were greater in men with higher biochemical markers of bone turnover at baseline. INTRODUCTION: This study aimed to determine prospective change in bone density and geometry at the radius in men and examine the influence of bone turnover markers and sex hormones on that change. METHODS: Men aged 40-79 years were recruited from population registers in Manchester (UK) and Leuven (Belgium). At baseline, markers of bone formation (P1NP and osteocalcin) and resorption (ß-cTX and ICTP) were assessed. Total and bioavailable testosterone and oestradiol were also measured. Peripheral quantitative computed tomography (pQCT) was used to scan the radius at distal and midshaft sites at the baseline assessment and a median of 4.3 years later. RESULTS: Five hundred fourteen men, mean (SD) age of 59.6 (10.5) years, contributed to the data. At the midshaft site, there was a significant decrease in mean cortical vBMD (-0.04 %/year), bone mineral content (BMC) (-0.1 %/year) and cortical thickness (-0.4 %/year), while total and medullary area increased (+0.5 and +2.4 %/year respectively). At the distal radius, total vBMD declined (-0.5 %/year) and radial area increased (+0.6 %/year). Greater plasma concentrations of bone resorption and formation markers were associated with greater decline in BMC and cortical area at the midshaft and total vBMD at the distal site. Increased bone resorption was linked with an increase in total and medullary area and decrease in cortical thickness at the midshaft. Sex hormone levels were unrelated to change in pQCT parameters. CONCLUSIONS: Age-related changes in vBMD and bone geometry are greater in men with higher biochemical markers of bone turnover at baseline. Sex hormones have little influence on change in pQCT parameters.