The association between dietary inflammatory index with sleep quality and obesity amongst iranian female students: A cross-sectional study

Background Overweight, obesity and lack of sleep quality as inflammatory states are the common problems amongst college students and the Association of Dietary Inflammatory Index (DII) with these problems amongst this population is unknown. We aimed to evaluate the relationship of the DII with obesity and sleep quality amongst Iranian female students. Methods The present cross-sectional study was conducted on 249 female college students. The Dietary Inflammatory Index (DII) was calculated using a valid and reliable 147-item food frequency questionnaire (FFQ). To assess sleep quality, Pittsburgh Sleep Quality Index (PSQI) was used. Odds Ratio (OR) and 95% Confidence Intervals (CIs) were estimated for anthropometric indices and sleep quality according to the DII score. Linear regression was used to estimate the relationship between DII score with sleep and anthropometric indices. Results There was a significant association evident between DII and sleep quality (>5 is considered as poor quality of sleep); ie, the odds ratios between DII quartile 2 vs 1 (unadjusted model: OR = 0.33 (CI: 0.14-0.74), P for trend = .002; model 1: the fully adjusted OR = 0.31(CI: 0.12-0.78), P for trend = .005; model 2:OR = 0.30 (CI: 0.12-0.78), P for trend = .005) to quartile 4(unadjusted model: OR = 1.13(CI: 0.45-2.80); model 1: OR = 1.11(CI: 0.44-2.79); model 2:OR = 1.13(CI: 0.44-2.87), P for trend = .005). Also, odds ratios increased significantly from quartile 2 to quartile 4 in all models for DII and sleep quality. According to the continuous score of DII, there was a significant positive association between DII and sleep quality in all three models: unadjusted, model 1, and model 2 (OR = 1.21 (CI: 1.05-1.40), OR = 1.21 (CI: 1.03-1.43), and OR = 1.22 (CI: 1.03-1.44), respectively. Conclusions In this study, after removing the effect of confounding factors, participants in the highest quartile of DII score had significantly higher PSQI global score.