Association study of the BDNF gene polymorphism (G196A) with overweight/obesity among women from Northwest of Iran

Abstract

Background: Obesity is a health problem defined by surplus body fat accumulation and is one of the leading causes of morbidity and mortality. Earlier studies indicated the influence of brain-derived neurotrophic factor (BDNF) molecular alterations in the development of obesity. One of these variations is the G196A single nucleotide polymorphism (Val66Met; SNP rs6265), which impairs intracellular trafficking and reduces the secretion of BDNF. In this study, we evaluated the possible association of G196A polymorphism of the BDNF gene with body mass index (BMI) among women from the Iranian Azeri Turkish ethnic group. Four hundred eighty-four women including 343 women with obesity or overweight and 141 age-sex and ethnically matched healthy controls were genotyped for G196A SNP of BDNF gene by applying polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP) method. The association of this polymorphism with BMI was evaluated using analysis of covariance (ANCOVA), and the comparison of alleles and genotypes frequencies between patients (obese and/or overweight participants) and healthy controls was carried out using logistic regression models. Results: Individuals carrying Met-Met genotype have a significantly lower mean of BMI in comparison to those carrying non-Met/Met polymorphisms (P = 0.0138). Conclusions: In this study, the association of the Val66Met polymorphism of the BDNF gene with BMI as an obesity trait has been confirmed among the women from the Northwest of Iran.