Bone metabolism markers in young high-performance athletes

Introduction. When assessing bone metabolism markers in athletes under the age of 18, it should be borne in mind that, in comparison with adults, the pediatric population is characterized by higher values of these markers. Their maximum increase during puberty coincides with peak bone mass gain. Objective. To evaluate bone metabolism status in healthy high-performance athletes under the age of 18 based on the levels of C-terminal telopeptide (β-CrossLaps), osteocalcin, and N-terminal propeptide human procollagen type 1 (P1NP) in the blood serum. Materials and methods. A single-center, сross-sectional study involved 383 juvenile athletes aged 13–18 years (248 girls and 135 boys; average age 15.2 [14.0; 16.1] years) from Russian national sports teams. The study was conducted in the period from March 2021 to July 2023. All athletes were divided into groups according to age and gender. The male groups were as follows: 13.1–14.0 years old ( n = 3); 14.1–15.0 years old ( n = 11); 15.1–16.0 years old ( n = 43); 16.1–17.0 years old ( n = 42); and 17.1–18.0 years old ( n = 36). The female groups were as follows: 13.1–14.0 years old ( n = 17); 14.1–15.0 years old ( n = 51); 15.1–16.0 years old ( n = 65); 16.1–17.0 years old (n = 59); and 17.1–18.0 years old ( n = 56). The serum levels of osteocalcin, C-terminal telopeptide, and procollagen type 1 were evaluated in all athletes. The sexual maturity rating (SMR) was assessed according to the Tanner Scale. Statistical data processing was performed using the Statistica 10.0 software package (StatSoft Inc.; USA). Results. The maximum values of β-CrossLaps in boys (2.27 [1.14; 3.45] ng/mL) and girls (1.55 [1.10; 2.02] ng/mL) were observed at the age of 13–14 years. The levels of osteocalcin and P1NP in young high-performance athletes corresponded to the standards for children with a normal level of physical activity. The maximum values of P1NP were revealed at the age of 13–14 years in both male (767.8 [148.1; 1142.4] ng/ mL) and female (450.5 [268.6; 569.3] ng/mL) groups. In boys, the maximum values of osteocalcin (125 [89; 144] ng/mL) were detected at the age of 14–15 years; in girls (86 [62; 131] ng/mL) — at the age of 13–14 years. Conclusions. In young high-performance athletes, the β-CrossLaps level as the main marker of bone resorption significantly exceeds the population norms for children and adolescents with a normal level of physical activity. When assessing the level of β-CrossLaps, osteocalcin, and P1NP, reference values should be adjusted to account for the gender and sexual maturity stage of athletes. The data obtained can be used when interpreting the results of an in-depth medical examination of athletes from Russian national sports teams to identify bone remodeling disorders.