ABSTRACT
OBJECTIVES: To analyze the mRNA expression of interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α) in the liver and white adipose tissue samples of individuals with class III obesity (body mass index ≥40.0kg/m2) with non-alcoholic fatty liver disease (NAFLD). METHODS: This cross-sectional study included patients with class III obesity exhibiting early or late morphological presentation of NAFLD (non-alcoholic hepatic steatosis [NAFL], n=8 and non-alcoholic steatohepatitis [NASH], n=13, respectively). All patients underwent bariatric surgery and peripheral blood, liver, and visceral white adipose tissue (WAT) samples were collected. Socio-demographic, anthropometric, clinical, plasma biochemical, and nutritional characteristics of each study subject were assessed and compared between patients presenting with NAFL and NASH. IL-6 and TNF-α mRNA expression in the liver and WAT samples were measured by using quantitative real time-polymerase chain reaction (qRT-PCR). RESULTS: Individuals with class III obesity and NASH showed higher body mass index (BMI) and higher IL-6 and TNF-α mRNA expression in the WAT compared to that of patients with NAFL (p=0.01, for all associations). CONCLUSIONS: Individuals with class III obesity with higher morphological severity of NAFLD exhibited higher BMI and higher IL-6 and TNF-α expression in the WAT. Future prospective studies are warranted to determine how BMI, IL-6, and TNF-α affect the progression of NAFLD in individuals with class III obesity.
Subject(s)
Body Mass Index , Interleukin-6/metabolism , Intra-Abdominal Fat/metabolism , Non-alcoholic Fatty Liver Disease/complications , Non-alcoholic Fatty Liver Disease/metabolism , Obesity, Morbid/complications , Tumor Necrosis Factor-alpha/metabolism , Adult , Bariatric Surgery , Biomarkers/metabolism , Cross-Sectional Studies , Female , Gene Expression Profiling , Humans , Inflammation Mediators/metabolism , Male , Middle Aged , Non-alcoholic Fatty Liver Disease/physiopathology , Non-alcoholic Fatty Liver Disease/surgery , Obesity, Morbid/metabolism , Obesity, Morbid/physiopathology , Obesity, Morbid/surgery , Severity of Illness Index , Young AdultABSTRACT
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.
