Objective:A number of candidate genes have been in implicated in the pathogenesis of obesity in humans. Tumor necrosis factor-alpha $(TNF-{\alpha})$ is expressed primarily in adipocytes, and elevated levels of this cytokine have been linked to obesity and insulin resistance. Recently, the A allele of a polymorphism at position 308 in the promoter region of $TNF-{\alpha}$ (G-308A) has been shown to increase transcription of the gene in adipocytes. Therefore, we designed this study to test whether obese and non-obese subjects differ in $TNF-{\alpha}$ genotype distribution, and how the genotypes affect anthropometric parameters, including degrees of body mass index (BMI).
Methods: The study included 153 obese but otherwise healthy women ($BMI{\geq}kg/m^2$, range 25-54.7, age range 15-40 years) and 82 non-obese healthy women ($BMI, age range 15-40 years). Total fat mass and percent body fat were determined by dual-energy X-ray absorptiometry. Genomic DNA was extracted and used for Ncol restriction fragment length polymorphism (RFLP) based genotyping of $TNF-{\alpha}$.
Results: No differences were observed for allelic and genotype frequencies between the obese ($BMI{\geq}25$) and non-obese women. Also, no association of TNF-(l polymorphism was observed with body mass index (BMI) for genotype in obese women. In addition, age, pertent body fat, BMI, and cholesterol levels did not differ by $TNF-{\alpha}$ genotype. However, waist-tohip ratio (WHR) was significantly lower in subjects with $TNF-{\alpha}$ GA or AA genotype (0.94 0.07 vs. 0.920.03, P<0.005).
Conclusion: These results suggest that $TNF-{\alpha}$ promoter polymorphism at position-308 is not a significant factor for BMI, but affects the WHR in obese healthy women from Koreans.
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