Gene polymorphisms in tumor necrosis factor locus and waist–hip ratio in obese Koreans

Abstract

Background: The study was designed to investigate the association among tumor necrosis factor-beta (TNFβ)+252A/G, TNF-alpha (TNFα)-308G/A polymorphisms and anthropometric parameters related to obesity in Korean obese subjects. Methods: The study included 152 obese healthy subjects (BMI≥25 kg/m 2, range 25.0–40.4, age range 15–40 years) and 82 non-obese controls (BMI<25 kg/m 2, age range 15–40 years). Total fat mass and percent body fat were determined by dual-energy X-ray absorptiometry (DEXA). Genomic DNA was extracted and used for NcoI restriction fragment length polymorphism (RFLP)-based genotyping of TNF. Results: No differences were observed for allelic and genotype frequencies between obese and non-obese subjects. Also, no association of TNF polymorphisms was observed with body mass index (BMI) for genotype in obese subjects. In addition, age, percent body fat, BMI and cholesterol concentrations did not differ from TNF genotypes. However, waist-to-hip ratio (WHR) was significantly decreased in subjects with TNFα A/TNFβ G haplotype compared with other haplotypes carriers (0.92±0.03 vs. 0.94±0.06, P=0.005). Conclusions: These results suggest that TNF polymorphisms at position −308 and +252 are not a significant factor for BMI, but affect the WHR in obese Koreans.