BACKGROUND: In obesity, increased tumor necrosis factor (TNF)-alpha level is 
involved in the development of insulin resistance. Toll-like receptor (TLR)-4 
and TLR2 are expressed in adipose tissue, and polymorphisms of these receptors 
may influence TNF-alpha secretion from adipocytes. In our study, TNF-alpha, 
soluble TNF receptor 1 (sTNFR1), and soluble TNF receptor 2 (sTNFR2) levels were 
determined, and any association between polymorphisms of TLR4 (D299G, T399I), 
TLR2 (R753Q, R677W), and cytokine levels was assessed in obese children and 
non-obese control subjects.
MATERIAL/METHODS: In a cross-sectional study, 79 obese children and 42 matched 
non-obese control children were investigated. Cytokine levels were measured by 
enzyme amplified sensitivity immunoassay. TLR4 and TLR2 polymorphisms were 
determined using polymerase chain reaction - restriction fragment length 
polymorphism technique.
RESULTS: TNF-alpha and sTNFR2 levels in obese children were significantly 
(P<.01) higher than controls. Significant (P<.05), positive, linear correlations 
were observed between TNF-alpha, sTNFR2 levels, and BMI. Patients carrying the 
mutant alleles of TLR4 (299G and 399I) had lower TNF-alpha and sTNFR2 levels 
compared to patients carrying wild-type alleles (299D and 399T) (TNF-alpha 
4.4+/-0.7 pg/mL vs 5.5+/-0.9 pg/mL; sTNFR2 2.9+/-1.2 ng/mL vs 4.4+/-1.1 ng/mL; 
P<.001). The R753Q polymorphism of TLR2 was not associated with altered cytokine 
levels, and the R677W polymorphism was not detected in the sample population.
CONCLUSIONS: Serum levels of TNF-alpha and its soluble receptors are elevated 
and associated with increasing BMI values in obese children. Serum cytokine 
levels, as modifying factors of insulin resistance, may be affected by TLR4 
polymorphisms in obese children.