Changes Of Serum Tumor Necrosis Factor-alpha(TNF-α) And Free Fatty Acid(FFA) Levels In Obese Patients And Their Relationship With Insulin Resistance(IR)

Objective: To ascertain the relationship between serum levels of TNF- a and FFA in isolated obese subjects and obese IGT patients and their association with IR.Methods: The serum TNF- a levels were measured in 25 isolated obese subjects(llmen, ISwomen, age59 + 12),25 obese IGT patients(10men,15women,age58 ?14),25 non-obese DM(13 men, 12women,age56 ?13)and 25 normal subjects(10men, ISwomen, age52眑l) by RIA method. Serum FFA levels were measured by colorimetric method, and their fast glucose(FPG), fast serum-insulin(FINS),total-serum cholesterol(TC), low density-lipoprotein cholesterol (LDL) and high density lipoprotein cholesterol(HDL) were measured at the same time. The results were compared between obese and non-obese DM, and non-DM groups.Results: Serum TNF- a levels were much higher in isolated obese (1.74 + 0.56 ng/ml)and obese IGT groups(l .76 ?0.81 ng/ml )than that in the normal control (0.54 + 0.22 ng/ml)and non-obese DM groups(0.78 ?0.2 lng/ml)(p< 0.01 )as well as the FFA serum levels(l.34+ 0.91 |amol/mK 1.41 ?0.89umol/mK 0.47 ?0.21umol/ml ^ 0.65 + 0.22(amol/ml)(p < 0.01).Any significant difference of serum TNF- a and FFA levels were shown neither between isolated obese and obese IGT groups nor between the normal control and non-obese DM groups. TNF- a and FFA showed positive correlation with FINS(r=0.55,r=0.43^BMI(r=0.68, r=0.43)in isolated obese group , and they positively correlated to FINS(r=0.52, r=0.52)> IR(r=0.51, r=0.55)and BMI(r=0.41, r-0.55) in obese IGT group. However, they had no association with other factors in non-obese DM and normal groups. Multiple regression analysis showed that both TNF- a and FFA positively correlated to BMI and WHR.Conclusion: The results indicate that serum TNF- a and FFA levels increase high in isolated obese and IGT obese patients, and there is a strong positive relationship between them. The positive relationship between TNF- a , FFA and IR suggests that they both take part in the occur of insulin resistance. TNF- a and FFA correlate to BMI and WHR in obese patients, and theyelevate accompanied with obesity worse, but hyperglucaemia has no influence on them.