(P23-010-23) Plasma miR-15a Levels Are Associated With Dietary Inflammatory Index and Inflammatory Status in Women: The 2015 ISA-Nutrition Study

Objectives: We investigated associations between the plasma expression of microRNAs (miRNA), Dietary Inflammatory Index (DII) and inflammatory status in adults from 2015 ISA-Nutrition Study, a household cross-sectional, population-based survey of residents from urban Sao Paulo, Brazil.

Methods: The analysis included 183 adults (aged 20-59 years, 54% female) without major systemic disease; use of antibiotics, anti-inflammatory, immunomodulators, antiretrovirals; chronic alcoholism; or pregnant/lactating women. The plasma expression of 21 miRNA was quantified by qPCR, using Spike-in cel-miR-39 and UniSp6 for normalization. Relative miRNA expression was calculated using the 2−∆∆CT method. Plasma interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-α, monocyte chemoattractant protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), adiponectin, hepcidin and leptin concentrations were determined by immunoassays and C-reactive protein by enzyme-linked immunosorbent assay. Energy-adjusted DII (EDII) was calculated from 29 nutrients and food components, with positive and negative EDII scores representing diets with proinflammatory and antiinflammatory potential, respectively. Multiple regression models were run to assess associations between EDII, miRNA expression and markers of inflammatory status.

Results: Participants were overweight/obese (59%) and 80% had a proinflammatory diet. Among 21 miRNA evaluated, only the plasma expression of miR-15a was associated with a pro-inflammatory EDII (β 0.31; 95% CI 0.001;0.612) and with higher IL-6:IL-10 ratio (β 0.03; 95% CI 0.001;0.05) in women, in the model adjusted for age and BMI. No associations were observed for the other inflammatory biomarkers evaluated or in men. Plasma expression of miR-15a was positively associated with the intake of trans fat (β 0.209; 95% CI 0.025;0.393) and negatively with vitamin C (β 0.03; 95% CI 0.001;0.05) and folate (β -0.003; 95% CI -0.005; -0.001).

Conclusions: Consumption of a proinflammatory diet is associated with increased plasma expression of miR-15a in women with proinflammatory status.

Funding Sources: São Paulo Research Foundation—FAPESP, grant numbers 2017/05125-7 and 2019/22934-1