Dietary inflammatory index is associated with severe depression in older adults with stroke: a cross-sectional study

Inflammation is involved in the pathogenesis of stroke and depression. We aimed to investigate the association between the dietary inflammatory index (DII) and depression in American adults with stroke. Adults with stroke were enrolled in the National Health and Nutrition Examination Survey between 2005 and 2018 in the USA. The DII was obtained from a 24-h dietary recall interview for each individual. Multivariate regression and restricted cubic spline analyses were conducted to evaluate the association between DII and depression in adults with stroke. The mean age of the 1239 participants was 63·85 years (50·20 % women), and the prevalence of depression was 18·26 %. DII showed a linear and positive association with severe depression in adults with stroke (OR 1·359; 95 % CI 1·021, 1·810; P for non-linearity = 0·493). Compared with those in the lowest tertile of the DII, adults with stroke in the third tertile of the DII had a 3·222-fold higher risk of severe depression (OR 3·222; 95 % CI 1·150, 9·026). In the stratified analyses, the association between DII score and severe depression was more significant in older adults (P for interaction = 0·010) but NS with respect to sex (P for interaction = 0·184) or smoking status (P for interaction = 0·396). No significant association was found between DII and moderate-to-moderately severe depression in adults with stroke. In conclusion, an increase in DII score was associated with a higher likelihood of severe depression in older adults with stroke.