Background: The role of TNF-alpha in contributing to obesity-associated cardiovascular and metabolic risk has gained much attention.
Materials and methods: Paired biopsies of omental and subcutaneous fat were collected from 16 lean subjects and 32 central obesity subjects. The expression of TNF-alpha in omental and subcutaneous fat was quantified by western blotting method, and correlations with plasma PAI-1, homeostasis model assessment insulin resistance (HOMA-IR), and lipid were investigated.
Results: In obese female, TNF-alpha expression was higher in the omental than in the subcutaneous fat tissue. There was no significant difference in the levels of TNF-alpha between subcutaneous and visceral fat in obese male. Significant positive correlations were found between omental TNF-alpha protein and plasma PAI-1 levels in obesity. In obese female subjects, omental TNF-alpha protein levels showed a close association with most of the parameters studied: fasting glucose (r=0.541, P<0.05); fasting insulin (r=0.599, P<0.01); HOMA-IR (r=0.546, P<0.05); triglycerides (r=0.469, P<0.05); HDL-cholesterol (r=-0.759, P<0.01). In obese male population, correlations between omental TNF-alpha protein levels and fasting glucose (r=0.762, P<0.01); fasting insulin (r=0.622, P<0.05); triglycerides (r=0.650, P<0.05); HDL-cholesterol (r=-0.880, P<0.01) were found.
Conclusion: Omental TNF-alpha may play a key role in contributing to cardiovascular risk in central obesity subjects.