Associação do potencial inflamatório da dieta com indicadores de adiposidade corporal e sintomas depressivos em uma coorte de estudantes universitários

Abstract

Obesity and depression are conditions that are associated with chronic low-grade inflammation. These outcomes represent a challenge for public health, with high prevalence worldwide. University students are a vulnerable group to the development of both outcomes, due to the exposure represented by the university environment, which contributes to unfavorable lifestyle changes. Specific dietary patterns and components may have pro- or anti-inflammatory effects. The Dietary Inflammatory Index (DII) assesses the inflammatory potential of the diet and enables analysis of its association with health outcomes. Thus, the main theme of this thesis is the estimation of the DII and its association with indicators of body adiposity and depressive symptoms in a dynamic cohort of university students called ELESEU (Longitudinal Study on Lifestyle and Health of University Students). Students entering in the years 2016 and 2017 in full-time courses at a public university in the Midwest Region of Brazil and who were followed up until 2018 were evaluated in this thesis. As results of this thesis, two scientific manuscripts were elaborated, with a longitudinal analysis of the data, having the inflammatory potential of the diet as the independent variable of interest, assessed by means of the DII at baseline and estimated from 39 dietary parameters obtained by 24-hour food recall. The first manuscript aimed to estimate the DII and analyze its association with the trajectory of body adiposity markers in university students. Linear mixed-effects model analysis was used to estimate the trajectory of adiposity markers (body mass index [BMI], body fat percentage, waist circumference, and waist-to-height ratio) according to the DII tertiles. DII values ranged from -3.81 to 3.44, with a mean of 0.51 (95% CI: 0.40; 0.61), showing an association with the increase in markers of body adiposity, however, this increase was not different over time. The second manuscript examined the DII association with the risk of depressive symptoms among university students. The presence of depressive symptoms was assessed by the Patient Health Questionnaire-9, and a cut-off point ≥ 10 was used for the classification of individuals with depressive symptoms. Generalized linear models with logistic function allowed estimation of the relative risk and confidence intervals for association between the DII and depressive symptoms, comparing the baseline with the study follow-ups. After adjustment for potential confounding factors, university students showed a 1.13 (p=0.05) risk for depressive symptoms for each increase in one unit of the DII after one year of follow-up, and at the second year of follow-up, the risk of depressive symptoms among young university students was 1.28 (p=0.01) compared to baseline. It is concluded that the pro-inflammatory diet was associated with an increase in body adiposity markers and contributed to the increased risk of depressive symptoms among university students.