Dietary Inflammatory Index and Magnetic Resonance Imaging–Detected Knee Structural Change and Pain: A 10.7‐Year Follow‐up Study

Abstract

ObjectiveTo determine whether the dietary inflammatory index (DII®) scores were associated with knee structural changes and pain over a 10.7‐year follow‐up.MethodsThis study utilised data from a prospective population‐based cohort study (mean age 63 years, 51% female) in which 1,099, 875, 768 and 566 participants completed assessments at baseline, 2.6, 5.1 and 10.7 years, respectively. T1‐weighted and T2‐weighted MRI was performed to measure cartilage volume (CV) and bone marrow lesions (BMLs) at baseline and 10.7 years. The Western Ontario and McMaster Universities Osteoarthritis Index pain questionnaire was used to measure knee pain at each visit. Pain trajectories (‘Minimal Pain’, ‘Mild Pain’, and ‘Moderate Pain’) were previously identified. Baseline energy‐adjusted DII (E‐DIITM) scores were calculated. Linear, log‐binomial regression, linear mixed‐effects modelling and multi‐nominal logistic regression were used for analyses.ResultsThe mean E‐DII score at baseline was ‐0.48±1.39. In multivariable analyses, higher E‐DII scores were not associated with tibial CV loss or BML size increase except for medial tibial BML size increase. Higher E‐DII scores were associated with greater pain score (β=0.21, 95% CI 0.004‐0.43) and an increased risk of belonging to ‘Moderate pain’ compared to ‘Minimal Pain’ trajectory group [relative risk ratio (RRR): 1.19, 95%CI 1.02‐1.39].ConclusionA proinflammatory diet, as indicated by higher DII score, may be associated with greater pain score and higher risk of more severe pain trajectory over 10 years. However, inconsistent findings related to structural changes suggest a discordance between the potential impact of diet on structural damage and pain in knee OA.