Serum bone turnover markers were associated with bone mass in late prepuberty and early puberty

Aim To analyse the association between bone turnover markers and bone mass in children and young adults. Methods This descriptive study followed 132 children (68 boys/64 girls) from Malm & ouml;, Sweden, as controls in a school-based intervention study (2000-2017). Height, weight, Tanner stage and bone mass were measured annually from ages 8 to 15 years, with follow-ups at 19 and 23 years of age. Serum markers for bone formation (bone-specific alkaline phosphatase (bALP), N-terminal propeptide of collagen type 1 (PINP), osteocalcin) and resorption (C-terminal telopeptide crosslinks (CTX), tartrate-resistant acid phosphatase (TRAcP 5b)) were collected at ages 9.9 +/- 0.6 (mean +/- SD) (n = 78), 12.0 +/- 0.6 (n = 64), 14.9 +/- 0.8 (n = 52), 18.8 +/- 0.3 (n = 34) and 23.3 +/- 0.6 years (n = 56). Results Compared to girls, boys showed higher bone turnover markers at ages 15, 19 and 23 years (all p < 0.05). At 10 years of age (Tanner stage 1 and 2), bALP and TRAcP 5b correlated with current bone mass (adjusted for age and sex), while bALP, PINP, osteocalcin and CTX correlated with bone mass change over the next 2 years (adjusted for age, sex and interval) (all p < 0.05). Conclusion Bone turnover markers in early Tanner stages predicted both current bone mass and subsequent bone mass changes.