Association between polymorphisms in PSCK9, INSIG2 and FTO genes and the development of metabolic Syndrome in patients with severe obesity

Abstract

Metabolic syndrome (MS) is a term used to characterize risk factors that directly increase the risk of type 2 diabetes, cardiovascular disease, obesity and mortality. There are different definitions or diagnostic criteria. The global prevalence of MS varies from 10% to 84% depending on the region, city or rural environment, population studied and the definition used for diagnosis. Environmental factors related to genetic factors are involved in the development of MS. Several single nucleotide polymorphisms (SNPs) are associated with risk factors that predispose to metabolic syndrome, however are not well-established genes involved in this process. The E670G polymorphism in the PCSK9 gene has an important role in cholesterol metabolism by modulating the number of low density lipoprotein receptor (LDLR), increasing circulating levels of LDL-cholesterol. The rs75666605 polymorphism in the INSIG2 gene also has established role in cholesterol metabolism and glucose. Moreover, the rs9939609 polymorphism in the FTO gene is directly related to an increased accumulation of body fat. Objective: To analyze the association between E670G polymorphisms in the PCSK9 gene, rs75666605 polymorphism in INSIG2 gene and rs9939609 polymorphism in FTO gene with the development of metabolic syndrome in patients with severe obesity. Patients and Methods: Will be selected 150 individuals of mixed population, between 18 and 60 years with obesity class II or III candidates for bariatric surgery, which will be selected in the Bariatric Surgery Clinic of the University Hospital of the Ribeirao Preto Medical School ( HCFMRP-USP). It is a transversal study in which all patients will be submitted to nutritional assessment (weight, height, body mass index and waist circumference), blood pressure measurement, questionnaire of life habits, personal history and family history of chronic diseases. Indeed, biological material will be collected (peripheral blood) for genetic (Polymerase Chain Reaction in real time) and biochemical analysis (fasting glucose, and lipid profile). Statistical analysis will be performed Kolmogorovi-Smirnov test, t test and Fisher test or chi-square test (p <0.05).