[Bone metabolism in child and adolescent athletes: a systematic review].

BACKGROUND: Physical exercise is beneficial for the prevention of osteoporosis. Bone metabolism markers are the main indicators of metabolic balance and may indicate early risk in bone tissue.

AIM: This systematic review aims to summarize and update present knowledge about bone metabolism markers in child and adolescent athletes.

METHOD: Literature search was conducted up to March 2017 in PubMed and Sport Discus. A total of 19 studies (case-control, longitudinal and randomized control trials) met the inclusion criteria and were included in the review.

RESULTS: In females, bone remodeling decreases with age independently of sport practiced. Athletes with amenorrhea had lower levels of both markers of bone turnover than control subjects. High-impact sports present higher biomarkers in females. A brief period of training have positive effects in bone formation markers in adolescent males.

CONCLUSIONS: The age, sex type of exercise and sport, and performance level of the subjects can deeply affect bone metabolism markers during adolescence. More studies are needed to establish common criteria for metabolic response to physical exercise in these stages.