Supplementary Material for: The relationship of dietary inflammatory index with anemia in diabetic kidney disease: a cross-sectional study of the NHANES

Objective: This study examined the relationship between the Dietary Inflammatory Index (DII) and anemia in patients with diabetic kidney disease (DKD).
Methods: All the data was obtained from the National Health and Nutrition Examination Survey (NHANES) from 2007-2018. The final analysis included 1918 DKD patients, with 500 experiencing anemia. Weighted multivariate logistic regression models were used to assess the association between DII and anemia, with results expressed as odds ratios.
Results: Elevated DII scores correlated with an increased incidence of anemia (OR=1.13, 95%CI: 1.02-1.25). When analyzed as categorical variables, DII scores of 1.57-2.64 (OR=1.77, 95%CI: 1.13-2.77) and >2.64 (OR=1.78, 95%CI: 1.12-2.85) were linked to higher anemia risk. Subgroup analyses revealed consistent associations in individuals aged 65 and older (OR=1.92, 95%CI: 1.16-3.17), those with serum iron levels <73 ug/dL (OR=2.01, 95%CI: 1.11-3.62), and males (OR=2.23, 95%CI: 1.21-4.11). Higher DII scores correlated with greater odds of moderate-severe anemia (OR=1.22, 95%CI: 1.07-1.38).
Conclusion: The results indicate that elevated DII scores are associated with an increased occurrence of anemia in DKD patients, emphasizing the importance of lowering pro-inflammatory food consumption as a potential strategy to prevent anemia in this group.