Relevance of brown adipose tissue in infancy and adolescence

Brown adipose tissue (BAT) was thought to disappear after infancy. Recent studies finding BAT in patients undergoing positron emission tomography/computed tomography (PET/CT) have renewed the interest in deciphering the relevance of this tissue in humans. Available data suggests that BAT is more prevalent in children than in adults, and that its activation during adolescence is associated to significantly less gains in weight and adiposity. Data also shows that pediatric patients with metabolically-active BAT on PET/CT examinations have significantly greater muscle volume than patients with no identifiable BAT. Both the activity and the amount of BAT increase during puberty. The magnitude of the increase is higher in boys when compared to girls, and closely related to gains in muscle volume. Hence, concurrent with the great gains in skeletal muscle during infancy and puberty, all infants and adolescents accumulate large amounts of BAT. These observations are consistent with in vitro investigations suggesting close interactions between brown adipocytes, white adipocytes, and myocites. In this review, we discuss the potential role of this tissue in regulating weight and musculoskeletal development in children.