Asociación entre polimorfismos de la región promotora del gen del factor de necrosis tumoral alfa (TNF-alfa) con obesidad y diabetes en mujeres chilenas / Association between tumor necrosis factor-alpha promoter polymorphisms and type 2 diabetes and obesity in Chilean elderly women

ABSTRACT

Background: Tumor necrosis factor-alpha (TNF-alpha) has an increased expression in the adipose tissue of obese subjects and is involved in insulin resistance. Aim: To screen for associations between -308G/A, -238G/A, -376G/A and -163G/A genetic variants of the TNF-alpha gene, diabetes and obesity-related variables. Material and methods: A group of 263 elderly women aged 60-90 years were recruited. Among them, an oral glucose tolerance test was performed and serum lipids measured in 100 women. TNF-alpha genotypes were determined by polymerase chain reaction (PCR) and analysis of restriction fragment lenght polymorphisms. Results: No significant differences were found when comparing allele frequencies in TNF-alpha polymorphisms of normal subjects with those having impaired glucose tolerance or type 2 diabetes. After excluding patients with previous diagnosis of diabetes, no significant differences by polymorphism carrier status were found for plasma levels of lipids, glucose and insulin. Additionally, no significant differences were found for the association between variables related to adiposity and the ¡308G/A polymorphisms. Conclusions: It is unlikely that polymorphisms in the promoter region of the TNF-alpha gene have a major influence in obesity and diabetes phenotypes in Chilean elderly women.