Association of SNP rs7181866 in the nuclear respiratory factor-2 beta subunit encoding GABPB1 gene with obesity and type-2 diabetes mellitus in South Indian population

Abstract GABPB1, known as nuclear respiratory factor 2 (Nrf2), activates mitochondrial genes that are responsible for oxidative phosphorylation. Earlier studies on GABPB1 reported that two single nucleotide polymorphisms (SNPs) such as rs7181866 and rs8031031, to be associated with increased endurance in athletes. In the present study, a cohort of 302 South Indians, including normoglycemic healthy controls, T2DM with and without obesity were genotyped for the two SNPs by PCR-RFLP method and correlated with serum adipokines. The ‘G’ allele of rs7181866 was found to be associated with obesity whereas rs8031031 didn't show any significant association with obese individuals. The increased levels of adipokines such as Leptin, IL-6 and TNF-α and decreased adiponectin were found among obese-T2DM, when compared to non-obese T2DM subjects. Further, Factor analysis on metabolic components revealed four factors which accounts for 71.5% for non-obese control and 88.3% for obese T2DM of variance. The bias-corrected and accelerated bootstrap analysis revealed GG genotype to have significant positive and negative correlation with both TNF-α and adiponectin. In conclusion, the G allele of (rs7181866 A/G) was found to be significantly associated with risk for obesity among T2DM subjects.