Brown and White Adipose Tissue Expression of IL6, UCP1 and SIRT1 are Associated with Alterations in Clinical, Metabolic and Anthropometric Parameters in Obese Humans

Aim: The present study aimed to analyze the expression of IL6, UCP1 and SIRT1 in adipose tissue (WAT and BAT) in association to clinical, metabolic and anthropometric parameters in obese humans. Methods: WAT and BAT samples from obese patients (n=27) were collected. IL6, UCP1 and SIRT1 markers were measured by qRT-PCR. The association between IL6, UCP1 and SIRT1 mRNA expression and anthropometric and clinical parameters were evaluated, using appropriate statistical tests. Results: Our results demonstrated that high levels of IL6 are associated with altered glucose levels in the WAT (p=0.01). In contrast, high levels of IL6 in the BAT were associated with decreased % fat (p=0.01) and fat weight (p=0.02) and increased mVO₂ (p=0.02) and VO₂ (p=0.02). For UCP1, a higher expression in the BAT was observed when compared to the WAT (p=0.0001). This gene expression was associated with lower values of BMI (p=0.03), % fat (P=0.02) and fat weight (P=0.02) and increased mVO₂ (p=0.041) and VO₂ (p=0.001). In the WAT, decreased levels of SIRT1 were associated with increased fat weight (p=0.02); in the BAT, associations were found for % fat (p=0.018) and mVO₂ (p=0.03). Conclusion: These results reveal different characteristics in the biological actions between WAT and BAT in obese humans. Increased levels of IL6, UCP1 and SIRT1 in the BAT were associated with metabolic parameters improvements.