ESR1 and FTO genetic variants: impact on body weight reduction following bariatric surgery

Abstract

Background Variation in reduction of body weight after bariatric surgery has been observed. Genetics may have a role in the varying outcomes among obese patients. Aim of this research work was to examine the effect of genetic variants within the Fat Mass and Obesity-Related gene (FTO) (rs9939609) and Estrogen Receptor Alpha gene (ESR1) (rs712221) on body weight reduction and blood glucose control in obese individuals, six months following laparoscopic sleeve gastrectomy (LSG). Patients and methods Ninety obese individuals with BMI ≥35 kg/m2 undergoing LSG were recruited and followed up after 6 months. Genotyping for FTO gene (rs9939609) and ESR1 gene (rs712221) variants was done using Real-Time PCR (TaqMan probes). Results FTO (rs9939609) genotype AA was found to be associated with more obesity before operation (P value 0.005) and lead to successful surgery and weight loss (P value 0.023, OR 0.080, 95%CI 0.009–0.702). Patients with risk allele A had more weight loss and BMI reduction after operation compared to patients with non-risk allele T (P value <0.001). ESR1 (rs712221) genotype TT was found to be associated with more reduction of body weight six months after surgery when compared to genotypes TA and AA (P value 0.001). Carriers of the allele T of the ESR1 (rs712221) had more reduction of HbA1c after operation compared to patients with allele A (P value <0.001). Conclusion The single nucleotide variants; rs9939609 of FTO and rs712221 of ESR1 may be considered potential predictors of body weight reduction and/or blood sugar control following bariatric surgery for obese individuals.