Research on the correlation between Dietary Inflammation Index (DII) and stroke is limited. Patients with high body mass index (BMI), as a high-risk group for stroke, require attention. Therefore, we aimed to examine the interactive effects of dietary inflammation and BMI on the risk of stroke among adults in the United States.

Overall, 9,384 participants were included in this study. The exposure variable was the DII, which was calculated based on the overall inflammatory effect score, and the outcome was stroke. Overall, there was a positive relationship between DII (as a continuous variable) and stroke. Increased level of DII was significantly associated with increased risk of stroke (odds ratio [OR]: 1.21, 95% CI: 1.06–1.38), which was enhanced by higher BMI (OR: 1.35, 95% CI: 1.15–1.58) with significant additive interactions. There was a significant secondary interaction of copresence of BMI ≥25 kg/m2, systolic blood pressure (SBP) ≥140 mmHg, and high DII for increased stroke, with a further increase in OR to 1.41 (1.19–1.67).

This cross-sectional study shows that the relationship between higher DII levels and the significant increase in stroke prevalence was further amplified in patients with SBP ≥140 mmHg and higher BMI.