Pro-inflammatory dietary pattern is associated with fractures in women: an eight-year longitudinal cohort study

Summary: In this study, during 8 years of follow-up, we reported that higher dietary inflammatory index values were associated with a higher risk of incident fractures in women, but not in men, after adjusting for potential confounders. Introduction: Inflammation is a key risk factor for many adverse outcomes in older people. While diet is a potential source of inflammation, little is known about the impact of inflammatory diet on fractures. Thus, we investigated whether higher Dietary Inflammatory Index (DII)(TM) ® scores are associated with fractures in a cohort of North American people. Methods: This longitudinal study with a follow-up of 8 years included 3648 participants (1577 males and 2071 females; mean age = 60.6 years) with/at risk of knee osteoarthritis participating with in the Osteoarthritis Initiative. DII scores were calculated using the validated Block Brief 2000 Food Frequency Questionnaire, categorized into sex-specific quintiles. Information on fractures was obtained through self-reported history of fractures at hip, spine, and forearm. The relationship between baseline DII score and incident fracture was assessed through a Cox's regression analysis, adjusted for potential baseline confounders, and reported as hazard ratios (HRs). Results: During 8 years of follow-up, 560 individuals developed fractures (15.4%). Adjusting for 10 potential confounders, women in the highest DII score quintile (i.e., most pro-inflammatory diet) had a significantly higher risk for fractures (HR = 1.46; 95% CI = 1.02-2.11) compared to women in the lowest quintile. An increase in one standard deviation of DII scores significantly predicted fracture onset in women (adjusted HR = 1.14; 95% CI = 1.02-1.27). The association between DII score and fractures was not significant among men or in the sample as whole. Conclusion: Pro-inflammatory diet is associated with a higher incidence of fractures in women but not men.