Adipose Tissue Depots and Inflammation After Lifestyle Intervention Among Latino Youth With Obesity

Background: Pediatric obesity is associated with increases in regional adipose tissue volume and organ fat content which contributes to an unfavorable shift in the pro- and anti-inflammatory milieus. Lifestyle intervention can reduce regional adipose tissue volume and organ fat content but whether these reductions are associated with changes in proand anti-inflammatory markers among youth with obesity is unknown. Methods: A total of 40 Latino youth with obesity (age 13.5±1.4 y, Female 42.5%, BMI percentile 98.3±1.1) completed a 6-month community-based lifestyle intervention that included nutrition and health education classes (1 d/wk) and moderate-to-vigorous physical activity (3 d/wk). Changes in hepatic fat fraction (HFF), pancreatic fat fraction (PFF), visceral adipose tissue (VAT) volume, and subcutaneous abdominal adipose tissue (SAAT) volume were measured by magnetic resonance imaging. Fasting serum samples were analyzed for markers of pro-inflammation (tumor necrosis factor-alpha, TNF-α; interleukin-6, IL-6, monocyte chemoattractant protein-1, MCP-1) and anti-inflammation (IL-1 receptor antagonist, IL-1ra; high-molecular weight adiponectin, Adpn). Pre-post changes were tested using longitudinal growth models, adjusting for age, sex, and BMI. Results: Lifestyle intervention resulted in significant reductions in HFF (8.6±0.9% to 6.6±0.7%, p=0.006) and SAAT volume (6,412±146.5 to 5944.6±174.0 cm3, p=0.001) with no significant changes in PFF or VAT volume (both p>0.05). TNF-α (1.7±0.1 to 1.5±0.1 pg/mL, p=0.033), IL-1ra (1,131.1±119.2 to 926.0±103.1 pg/mL, p=0.026), and Adpn (1.9±0.3 to 1.6±0.3 µg/mL, p=0.004) were significantly reduced, whereas no changes were observed in IL-6 or MCP-1 (both p>0.05). Conclusions: Lifestyle-induced reductions in HFF and SAAT volume were accompanied by reductions in TNF-α, IL-1ra and Adpn among high-risk Latino youth. Whether reductions in adipose tissue depots mediate improvements in the inflammatory milieus, or vice versa, following lifestyle intervention has yet to be established.