The relationship between the dietary inflammatory index and prevalence of radiographic symptomatic osteoarthritis: data from the Osteoarthritis Initiative.

PURPOSE: To investigate whether higher dietary inflammatory index (DII((R))) scores were associated with higher prevalence of radiographic symptomatic knee osteoarthritis in a large cohort of North American people from the Osteoarthritis Initiative database. METHODS: A total of 4358 community-dwelling participants (2527 females; mean age 61.2 years) from the Osteoarthritis Initiative were identified. DII((R)) scores were calculated using the validated Block Brief 2000 Food-Frequency Questionnaire and scores were categorized into quartiles. Knee radiographic symptomatic osteoarthritis was diagnosed clinically and radiologically. The strength of association between divided into quartiles (DII((R))) and knee osteoarthritis was investigated through a logistic regression analysis, which adjusted for potential confounders, and results were reported as odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: Participants with a higher DII((R)) score, indicating a more pro-inflammatory diet, had a significantly higher prevalence of radiographic symptomatic knee osteoarthritis compared to those with lower DII((R)) score (quartile 4: 35.4% vs. quartile 1: 24.0%; p < 0.0001). Using a logistic regression analysis, adjusting for 11 potential confounders, participants with the highest DII((R)) score (quartile 4) had a significantly higher probability of experiencing radiographic symptomatic knee osteoarthritis (OR 1.40; 95% CI 1.14-1.72; p = 0.002) compared to participants with the lowest DII((R)) score (quartile 1). CONCLUSIONS: Higher DII((R)) values are associated with higher prevalence of radiographic symptomatic knee osteoarthritis.