Decrease of the DNA methylation levels of the ADRB3 gene in leukocytes is related with serum folate in eutrophic adults

Yohanna de Oliveira, Raquel Patrícia Ataíde Lima, Rafaella Cristhine Pordeus Luna, Mussara Gomes Cavalcanti Alves Monteiro, Cássia Surama Oliveira da Silva, Rayner Anderson Ferreira do Nascimento, Keylha Querino de Farias Lima, Ana Hermínia Andrade e Silva, Flávia Emília Leite de Lima Ferreira, Rodrigo Pinheiro de Toledo Vianna, Ronei Marcos de Moraes, Naila Francis Paulo de Oliveira, Aléssio Tony Cavalcanti de Almeida, Alexandre Sérgio Silva, Alcides da Silva Diniz, Maria José de Carvalho Costa, Maria da Conceição Rodrigues Gonçalves

DNA methylation has been evidenced as a potential epigenetic mechanism related to various candidate genes to development of obesity. Therefore, the objective of this study was to evaluate the DNA methylation levels of the ADRB3 gene by body mass index (BMI) in a representative adult population, besides characterizing this population as to the lipid profile, oxidative stress and food intake. This was a cross-sectional population-based study, involving 262 adults aged 20-59 years, of both genders, representative of the East and West regions of the municipality of João Pessoa, Paraíba state, Brazil, in that were evaluated lifestyle variables and performed nutritional, biochemical evaluation and DNA methylation levels of the ADRB3 gene using high resolution melting method. The relationship between the study variables was performed using analyses of variance and multiple regression models. All results were obtained using the software R, 3.3.2. From the stratification of categories BMI, was observed a difference in the average variables values of age, waist-to-height ratio, waist-to-hip ratio, waist circumference, triglycerides and intake of trans fat, which occurred more frequently between the categories "eutrophic" and "obesity". From the multiple regression analysis in the group of eutrophic adults, it was observed a negative relationship between methylation levels of the ADRB3 gene with serum levels of folic acid. However, no significant relation was observed among lipid profile, oxidative stress and food intake in individuals distributed in the three categories of BMI. A negative relationship was demonstrated between methylation levels of the ADRB3 gene in eutrophic adults individuals with serum levels of folic acid, as well as with the independent gender of BMI, however, was not observed relation with lipid profile, oxidative stress and variables of food intake. Regarding the absence of relationship with methylation levels of the ADRB3 gene in the categories of overweight, mild and moderate obesity, the answer probably lies in the insufficient amount of body fat to initiate inflammatory processes and oxidative stress with a direct impact on methylation levels, what is differently is found most of the times in exacerbated levels in severe obesity.