Impaired Cold Stimulated Supraclavicular Brown Adipose Tissue Activity in Young Boys with Obesity

Childhood obesity is a growing worldwide problem. In adults, lower cold-induced brown adipose tissue (BAT) activity is linked to obesity and metabolic dysfunction; this relationship remains uncertain in children. In this cross-sectional study, we compared cold-induced supraclavicular (SCV) BAT activity (percent change in proton density fat fraction (PDFF)) within the SCV region after one hour of whole-body cold exposure (18°C), using magnetic resonance imaging (MRI) in 26 boys aged 8-10 years: 13 with normal body mass index (BMI), and 13 with overweight/obesity. Anthropometry, body composition, hepatic, and visceral fat (VAT), and pre-and post-cold PDFF of the subcutaneous adipose tissue (SAT) in the posterior neck region and the abdomen were measured. Boys with overweight/obesity had lower cold-induced percent decline in SCV PDFF compared to those with normal BMI (1.6±0.8 vs 4.7±1.2 %, p=0.044). SCV PDFF declined significantly in boys with normal BMI (2.7±0.7 %, p=0.003) but not in boys with overweight/obesity (1.1±0.5 %, p=0.053). No cold-induced changes in the PDFF of either the neck SAT (-0.89±0.7 %, p= 0.250 vs 0.37±0.3 %, p= 0.230) or the abdominal SAT (-0.39±0.5 %, p=0.409 and 0.25±0.2 %, p= 0.139 for normal BMI and overweight/obesity groups respectively) were seen. The cold-induced percent decline in SCV PDFF was inversely related to BMI (r=-0.39, p= 0.047), waist circumference (r= -0.48, p= 0.014), and VAT (r= -0.47, p= 0.014). Thus, in young boys, as in adults, BAT activity is lower in those with overweight/obesity, suggesting that restoring activity may be important for improving metabolic health.