[Association between TNF-alpha promoter G-308A and G-238A polymorphisms and obesity in Tehran lipid glucose study population]

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. Therefore, we examined the relationship between the G-308A and G-238A polymorphisms of TNF-alpha gene promoter variants and obesity in an Iranian population. Subjects of the Tehran Lipid and Glucose Study classified into two age groups under and above 18. Adults classified in three groups according to their body mass index and less than 18 years old subjects classified in two groups [under 85th percentile for their age and sex and above 85th percentile]. 244 persons were selected to examine -308 site and 239 persons were selected to examine -238 site. The mentioned polymorphisms were examined with PCR and RFLP methods. The allele frequency of TNF-alpha polymorphism was in the Hardy Weinberg equilibrium and there was no relation between BMI and the frequency of this allele. No association between G-308A and G-238A TNF-alpha promoter polymorphisms and obesity could probably indicate that it is not an important risk factor for obesity and consequently for cardiovascular disease

Association of TNF-alpha promoter G-308A polymorphism and body mass index and other obesity effective factors in Tehran lipid and glucose study

Obesity cause a lot of disease such as cardiovascular, type 2 diabetes, obstructive sleep apnea, some types of cancers and osteoarthritis. Reports show polymorphism at position -308 in the promoter region of TNF-alpha increase transcription of the gene in adipocytes. We, therefore, examined the relationship between this variant and BMI as an obesity criterion and other obesity affective factors in an Iranian population. 244 Subjects were randomly selected from the Tehran lipid and Glucose study which is a Cross Sectional Study and they were classified in two age groups under 18 and above 18. We measured FBS, HDL-C, LDL-C, triglyceride, cholesterol levels, CRP, IL-6, IL-10, Adiponectin, and HOMA for all individuals. Factors including Body mass index and blood pressure were measured too. A 107bp segment of the mentioned gene with PCR [Polymerase Chain Reaction] was amplified and the polymorphism with RFLP [Restriction Fragment Length Polymorphism] revealed. Undistributed Data were analyzed by kruskal-Wallis test and distributed Data were analyzed by ANOVA. We used one-way ANOVA test followed by post hoc multiple comparison [Tukey] to compare laboratory findings of BMI groups. All data were analyzed using SPSS 16. The allele frequency of TNF-alpha polymorphism was in the Hardy Weinberg equilibrium and the Genotype of all 244 subjects were GG[85.7%], GA[13.1%],AA[1.2%] and there was no relation between BMI and the frequency of this allele. In adolescent sbp] systolic blood pressure] in girls at GA state was significantly more than GG and CRP in boys at AA state was significantly more than the two other state In adult cholesterol in men at AA was significantly more than the two other state and LDL-C in women in GG was more than the two other state. Data from this study shows no association between G-308A TNF-alpha promoter polymorphism with increasing BMI, so probably it is not important risk factor for obesity in Iranian populations