Changes in Brown Adipose Tissue in Boys and Girls during Childhood and Puberty

Abstract

Objective To characterize the changes in brown adipose tissue (BAT) during puberty in boys and girls. Study design We examined the prevalence and the volume of BAT at different stages of sexual development in pediatric patients who underwent positron emission tomography/computer tomography (PET/CT) studies. Results Of the 73 patients, 43 (59%) had BAT depicted on PET/CT. Visualized BAT was significantly less prevalent in PET/CT studies of pre-pubertal (Tanner stage 1) children than pubertal (Tanner stages 2-5) subjects (15% vs. 75%). Values for the volume of BAT also increased during puberty, but the magnitude of the increase was substantially greater during the final two stages of puberty (Tanner stage 4 or 5) than in earlier stages of sexual development (Tanner stages 1, 2, and 3) (Boys: 499±246 vs. 50±36, p <0.0001, Girls: 286±139 vs. 36±29, p = 0.024). Changes in BAT volume were also significantly greater in boys than in girls (p = 0.004) and were closely related to muscle volume (r’s = 0.52, 0.64 and both p’s<0.01, for boys and girls, respectively). Conclusion The depiction and the volume of brown fat increase during puberty. Metabolic and hormonal events related to the achievement of sexual maturity are likely responsible for the rapid increase in brown fat that occurs during puberty.

Discrimination Between Brown and White Adipose Tissue Using a 2-Point Dixon Water–Fat Separation Method in Simultaneous PET/MRI

“…Previous PET/CT studies provide conflicting information about sex dependence of BAT in pediatric cohorts (15,20), and further investigations should also determine sex effects on the presence and development of BAT.…”

“…To identify regions of BAT, the supraclavicular/cervical region was examined, because areas of adipose tissue can be easily identified and delineated in this area on anatomic images, and BAT in this region has been broadly characterized in PET/CT and autopsy studies (2,3,7,20). For areas of WAT, gluteal fat depots were evaluated because they are definable in every patient, and we expected to find exclusively WAT in the gluteal fat depots (3,29).…”

“…The development of precise and reliable tools for the quantification of body fat, its distribution, and determination of its type is highly needed. Several recent studies have investigated 18 F-FDG PET for identification of BAT, making PET/ CT a reference modality in BAT imaging (7,14,19,20) in particular as it is depicting metabolic activity of BAT depots. Nevertheless, MR imaging is currently thought of as the best tool in the evaluation of body fat because of its detailed soft-tissue characterization, superior spatial resolution, and the lack of exposure for the patient to ionizing radiation (21,22).…”

MRI characterization of brown adipose tissue in obese and normal-weight children

“…The recognition of BAT in children was first demonstrated in PET/CT scans from children with oncological conditions as part of routine cancer surveillance [19][20][21][22][23]. These studies have demonstrated that the volume and activity of BAT increases from childhood to adolescence [21] and during puberty [22,23]. However, FDG PET may not be the ideal imaging modality to identify and quantify brown adipose tissue.…”

Comparison of brown and white adipose tissues in infants and children with chemical‐shift‐encoded water‐fat MRI

“…Overweight subjects with high body-massindices (BMI) typically do not exhibit BAT uptake of 18F-FDG radiotracer in comparison to leaner subjects (7,8). Although BAT was traditionally believed to be present in all neonates and thought to be gradually lost after infancy, recent works have demonstrated on the contrary that metabolically active BAT is prevalent in pediatric and adolescent cohorts (9)(10)(11), as well as in adults (12,13).…”