Relação do polimorfismo RS1801282 do Gene PPARY com obesidade e síndrome metabólica em adolescentes: um estudo de coorte em São Luís-MA

Abstract

Obesity, characterized by excessive accumulation of body fat, is often identified using the body mass index. Obese individuals, especially those with excess abdominal fat, are at an increased risk of developing metabolic syndrome (MetS). Both, obesity and MetS are directly related to diseases of the cardiovascular system, of multifactorial origin determined by a complex interaction between genetic and environmental factors. Single Nucleotide Polymorphisms (SNP) in several genes have been associated with protective factors or genetic predisposition for the development of these clinical outcomes, such as the rs1801282 polymorphism of the PPARγ gene related to adipogenesis, glucose and lipid metabolism, as well as inflammatory processes. Therefore, the chapter I of this research presents a systematic review, whose main objective was to summarize results of studies that associated the rs1801282 polymorphism with obesity in adolescents and children. The methodology was the active search for scientific articles in databases in Portuguese and English, only studies with genotyping data for this genetic variant being included. The results found demonstrate that the development of obesity and metabolic disorders may be associated with the rs1801282 polymorphism of the PPARγ gene, but this relationship is interfered by other factors such as sex, ethnicity, and lifestyle habits, in addition to complex biomolecular mechanisms, with not therefore, there is a consensus in the literature regarding the action of this gene. In chapter II, the proposal was to correlate obesity, indicators of metabolic syndrome with the presence of the rs1801282 polymorphism in a group of adolescents. This research is a cross-sectional design, nested within a birth cohort in the city of São Luís, MA, with the participation of 491 individuals, 248 obese adolescents (case) and 243 non-obese (control). In the analysis, socioeconomic, demographic, behavioral, anthropometric, clinical, biochemical, and genetic variables were evaluated. The results demonstrated that obese adolescents had altered BMI, waist circumference and LDL compared to the control group (p<0.001). The frequency of the polymorphic allele (G) was 8.55% in the study population, but there was no direct association with the development of obesity. However, the association analysis of genotypes with components related to Metabolic Syndrome demonstrated that systolic blood pressure (SBP) showed significant differences between genotypes in the group of obese adolescents, with GG individuals having lower SBP values (p=0.027), as well as glycemic rates showed differences between the groups, with heterozygous individuals (CG) in the non-obese group having lower blood glucose levels (p=0.005). Thus, in this population of adolescents from a Brazilian cohort, the rs1801282 polymorphism of the PPARγ gene was associated with protective factors related to the components of MetS.