Changes in brown adipose tissue in boys and girls during childhood and puberty.

OBJECTIVE To characterize the changes in brown adipose tissue (BAT) occurring during puberty in boys and girls. STUDY DESIGN We examined the prevalence and the volume of BAT at different stages of sexual development in 73 pediatric patients who underwent positron emission tomography (PET)/computed tomography (CT) studies. RESULTS Of the 73 patients studied, 43 (59%) had BAT depicted on PET/CT. The presence of BAT was detected significantly less frequently on PET/CT in prepubertal subjects (Tanner stage 1) than in pubertal subjects (Tanner stages 2-5) (15% vs 75%). BAT volume also increased during puberty, with a significantly greater magnitude of the increase in the final 2 stages of puberty (Tanner stages 4 and 5) than in earlier stages (Tanner stages 1-3) (boys: 499 ± 246 vs 50 ± 36, P < .0001; girls: 286 ± 139 vs 36 ± 29, P = .024). Changes in BAT volume were also significantly greater in boys than in girls (P = .004) and were closely related to muscle volume (r = 0.52, P < .01 for boys; r = 0.64, P < .01 for girls). CONCLUSION The presence and volume of BAT increase rapidly during puberty. Metabolic and hormonal events related to the achievement of sexual maturity are likely responsible for this increase.