Influência do polimorfismo do gene Pro12Ala do PPAR-Y 2 sobre os parâmetros antropométricos, hemodinâmicos e autônomicos de adolescentes obesos

Abstract

Introduction: PPAR-γ 2 is a nuclear receptor that differentiates adipocytes, adequately stores lipids and attenuates hypertension. The PPAR - γ 2 Pro 12 Ala gene polymorphism reduces the activity of this receptor by up to 50%. Therefore, this polymorphism has been associated with obesity, arterial hypertension and other cardiovascular diseases. Since hypertension and obesity provide autonomic imbalance, it is not yet known if this genetic mutation can be associated with an increase in sympathetic nervous expression in obesity and Other autonomic modular changes. Objective: To analyze the influence of PPAR-γ 2 Pro12 Ala gene polymorphism on the anthropometric, hemodynamic and autonomic parameters of obese adolescents. Materials and methods: A cross-sectional study was carried out in São Luís, Brazil, with 95 adolescents between 11 and 19 years of age, divided into groups of eutrophic (GE), obese (GO) and obese with polymorphism (GOP). The measurements of height, weight, BMI,% of fat, BP and sexual maturation were obtained. Heart rate data were also collected through the ECG for the autoregressive analysis of heart rate variability, considering the variables SDNN, RMSSD, LF and HF (ms and n.u), in addition to the LF / HF index. The identification of the polymorphism was examined By genotyping for Pro12Ala using the Restriction Fragment Polymorphism - Polymerase Chain Reaction (PCR - RFLP). ANOVA was used to compare the groups. Results: The genotype frequency corresponded to Pro / Pro 81%, Pro / Ala 16%. Pro allelic frequency was 90% and Ala was 9%. Variables that were significantly increased in GOP compared to GE (p <0.05 ) Were: body weight (61.3 kg vs.47.5 kg), waist circumference (74.4 cm vs.63.7 cm) and fat mass% (25.6% vs.18.6%) . Significantly higher values of GO were compared with SBP (113.7 mmHg vs.104.5 mmHg), DBP (66.0 mmHg vs.60.2 mmHg), LF n.u (50.56 n.u vs. .38.71 n.u), HF% (49.46 n.u vs..61.29 n.u) and LF / HF index (1.13 vs.0.68). Conclusion: Obesity is an independent condition for autonomic modulation alterations, since the polymorphism of the Pro 12 Ala gene did not influence the anthropometric, hemodynamic and autonomic alterations of obese adolescents.