Association between the glutathione S-transferase P1 (GSTP1) Ile105Val gene polymorphism in obese and overweight patients over 60 years Associação entre o polimorfismo Ile105Val do gene da glutationa S-transferase P1 (GSTP1) em pacientes obesos e com sobrepeso acima de 60 anos

Introduction: Obesity is related to the possibility of a number of metabolic damage associated with oxidative stress. The enzymes of the glutathione S-transferase (GST) family have the function of promoting detoxification; however, polymorphisms in the glutathione S-transferase P1 (GSTP1) gene generate less efficient alleles as well as a decrease in their amount and activity. Objective: This study aimed to analyze the frequency of the alleles (A and G) and the genotypes of the GSTP1 Ile105Val gene polymorphism, and its association with obesity in the elderly. Materials and methods: This was a cross-sectional study involving 232 subjects aged between 60-98 years, of both sexes, originating from southern Brazil. The volunteers were categorized according to the body mass index (BMI) in three groups: normal weight (n = 52), overweight (n = 133), and obese (n = 47). Anthropometry was evaluated and the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used for genetic analysis, from peripheral blood samples. Results: The allelic frequency in the elderly obese group was 37.2% for A and 62.8% for G allele, and the genotypic frequency observed was AA 8.5%, AG 57.4% and GG 34.1%. Both the G allele as the GG and AG genotypes were significantly higher in the obese group compared to the other groups (p < 0.001). Conclusion: A higher prevalence of the G allele was observed in elderly obese group, responsible for encoding an abnormal enzyme and consequent reduction of antioxidant defenses, which contribute to inflammation process and obesity in the elderly.