Common mental disorders and their relationship with dietary patterns, plasma microRNA expression and intestinal permeability and inflammatory biomarkers in adults and older adults participants in the ISA Capital study

Abstract

Common mental disorders correspond to one of the main groups of morbidities associated with the risk of developing disabilities. Several studies show the role that diet plays on mental health outcomes, and more recent research has shown the effects of microRNA expression and inflammation biomarkers (including those of intestinal origin) on the pathophysiology of mental disorders. However, no study has presented results of the impact of these molecules on the relationship between diet and mental disorders. In this context, the objective of the present project will be to investigate the association between common mental disorders, dietary patterns, plasma microRNA expression, intestinal permeability, and inflammatory biomarkers in adults and older adults. The participants are part of the 2015 Health Survey of São Paulo (ISA-Capital) database, which is a population-based cross-sectional study, of the population residing in an urban area of São Paulo. The present study will use data from participants aged 18 or over. The presence of common mental disorders will be identified by the Self Reporting Questionnaire-20 (SRQ-20). Factor analysis will evaluate the dietary pattern, with food consumption data obtained by 24-hour food recall. The microRNA expression was analyzed in the aliquots of plasma using real-time qPCR. The microRNA that will be investigated were defined by a literature review: miR-16, miR-140-5p, miR-363, miR-486-5p, and miR-let-7c. Intestinal permeability will be evaluated by determining the serum concentration of lipopolysaccharide (LPS), zonulin, and intestinal fatty acid binding protein (I-FABP). The inflammatory biomarkers will be analyzed by the serum concentration of 11 inflammatory biomarkers: interleukin (IL-1²), IL-6, IL-10, tumor necrosis factor alpha, monocyte chemotactic protein 1, plasminogen activator inhibitor 1, and plasminogen activator molecules. 1 intercellular and vascular soluble adhesion. The associations between the independent variables and the outcome will be investigated by logistic regression models, adjusted and unadjusted. Mediation analysis will be conducted by structural equation modeling to assess indirect effects between the variables. A significance level of 5% (p < 0.05) will be adopted. Data analysis will be performed by the statistical programs Stata (version 14) and Mplus.