Bone turnover markers predict bone mass development in young adult men: a five-year longitudinal study.

CONTEXT Peak bone mass is an important factor for the lifetime risk of developing osteoporosis. Ways to predict bone development in young adulthood are lacking. Objective and Main Outcome Measures: The aim of this study was to investigate whether baseline measurements of bone turnover markers could predict bone development in early adulthood in men. DESIGN, SETTING, AND PARTICIPANTS In total, 817 men (age at baseline, 18.9 ± 0.6 y; mean ± SD) from the population-based Gothenburg Osteoporosis and Obesity Determinants Study were included in this 5-year longitudinal study. Areal bone mineral density (aBMD) and bone mineral content (BMC) were measured using dual-energy x-ray absorptiometry, and volumetric BMD (vBMD) and cortical bone size were measured using peripheral quantitative computed tomography. Blood samples were collected at the baseline visit, and levels of osteocalcin (OC) and N-terminal telopeptide of type I collagen were analyzed. RESULTS OC was a positive predictor of the increase in aBMD and BMC of the total body (R(2): aBMD, 6.6%; BMC, 4.9%), lumbar spine (R(2): aBMD, 5.4%; BMC, 5.7%), and radius (R(2): aBMD, 14.8%; BMC, 12.8%) between 19 and 24 years (P < .001). Men in the highest OC quartile at baseline (35.2 ± 4.4 ng/mL; mean ± SD) gained markedly more in radius cortical cross-sectional area (4.0 ± 4.3 vs 1.9 ± 2.9 mm(2)) and trabecular vBMD (11 ± 7 vs 3 ± 12 mg/mm(3)) than men in the lowest OC quartile at baseline (17.7 ± 2.3 ng/mL; mean ± SD) (P < .001). CONCLUSION A high OC level at the age of 19 predicts a favorable development in BMD, BMC, and bone size between 19 and 24 years of age.