Associação do polimorfismo da enzima Superóxido Dismutase Dependente de Manganês (MnSOD) com marcadores redox, inflamatórios, atividade física e consumo alimentar dos idosos do Emisus

Abstract

INTRODUCTION: Aging is a biologically natural process involving several morphophysiological changes. Some studies have recommended that food consumption rich in fruits, vegetables and proteins and the regular practice of physical exercise, can contribute to achieve an aging with fewer morbidities. On the other hand, studies have suggested that poor food intake in foods rich in antioxidant molecules combined with sedentary lifestyle is closely associated with chronic inflammation and oxidative stress. The action of antioxidant systems can minimize the damage caused by free radicals and / or reactive oxygen species (RL / ERO) to the body. One of the major defense against (RL / ERO) enzymes is the manganese-dependent enzyme superoxide dismutase (MnSOD). The gene encoding this enzyme is polymorphic and the Val16Ala variant is linked to aging, oxidative stress, and non-transmissible chronic diseases. PURPOSE: to verify the association of the Val16Ala polymorphism with REDOX and inflammatory markers, along with diet in the elderly participants of the EMISUS study. METHODS: Cross-sectional, observational and descriptive study. Based on the data obtained in the Epidemiological and Clinical Study of the Elderly attended by the Family Health Strategy (FHS) of the Municipality of Porto Alegre - EMISUS, conducted between March 2011 and December 2012. In all individuals, the following variables were investigated : Demographic: gender, age, marital status, schooling and income; Anthropometric: weight, height, body mass index (BMI) and waist circumference; Biochemical: total cholesterol (Col-T), triglycerides, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and glucose; Inflammatory: C-reactive protein (USP) and Interleukin-6 (IL-6); REDOX markers: advanced protein oxidation products (AOPP), ischemia-modified albumin (IMA), nitric oxide metabolites (NOx), plasma iron abatement capacity (FRAP), and malondialdehyde (MDA) and MNSOD gene polymorphism. The Val16Ala polymorphism was evaluated by Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP); Physical activity: sedentary, active and caloric expenditure; Diet: intake of fruits, vegetables and proteins of plant and animal origin. Data were analyzed using descriptive statistical analysis (percentage, median, mean and standard deviation) and ANOVA. For the verification of the balance between allele and genotype frequencies the Hardy-Weinberg formula was applied. The level of significance was set at p <0.05. RESULTS: 270 elderly people with mean age of 68.5 ± 7.5 years were evaluated. Most of the sample consisted of the female 168 (62.2%) and the majority of the white 175 (65.8%). The allele 11 frequencies were as follows: A = 0.54 and V = 0.46 and the genotype frequencies were: 54.4% of AV, 18.5% VV and 27.03% of elderly with AA genotype. Older individuals with AA genotypes more frequently have AOPP in the quartile 25 [157.8 μmolL (137.1 μmolL -190.9 μmolL)], whereas elderly individuals with VV genotype have AOPP in the quartile 75 [103,6 μmolL (96, 8 μmol -114.0 μmolL)] (P = 0.023). Older individuals with AA genotypes more frequently have FRAP in the quartile 50 [627.0 μmolL (526,0 μmolL -718,5 μmolL)] and genotypic VV, in quartile 25 [190,0 μmolL (100,0 μmolL -370, 0 μmolL)] (P = 0.038). No statistically significant differences were observed between MNSOD genotypes and MDA, NOx and IMA oxidative markers. Regarding food intake, most of the elderly reported consuming two or more weekly portions of vegetables and eggs (87.2%) and 66.7% and consuming at least two daily servings or more of fruits and vegetables. It was observed that heterozygotes consumed two or more daily servings of fruits and vegetables (P = 0.017), homozygotes for allele A, ingested two or more weekly portions of vegetables and eggs, (P = 0.002). The median HOMA-IR was higher in the elderly with VV genotypes than in the AV genotype (P = 0.029), the median insulin was higher in the VV genotype than in the AV (P = 0.025). In relation to the lipid profile, it was verified that the group with that of the AA genotype presented higher averages of high density lipoprotein concentration, in relation to the AV (P = 0.029). CONCLUSION: Val16Ala polymorphism is associated with AOPP and FRAP levels and is also associated with fruit, vegetable, vegetable and egg consumption, as well as cardiometabolic risk factors in the elderly. However, no association of this polymorphism with the caloric expenditure in this sample was found.