THU0679 ADHERENCE TO THE MEDITERRANEAN DIET AND RISK OF RHEUMATOID ARTHRITIS IN THE FRENCH PROSPECTIVE E3N COHORT STUDY

Abstract

Background The Mediterranean diet (MD), widespread in Southern European countries, mainly consists of olive oil, cereal products, fresh or dried fruit and vegetables, nuts, a moderate amount of dairy and meat, and many condiments and spices. It has been associated with significant reduction of overall mortality, cardiovascular diseases, and neoplastic diseases. It has been suggested to have a beneficial effect on rheumatoid arthritis (RA) activity due to its richness in antioxidants and unsaturated fatty acids. However, data on MD as a prevention of RA are limited. Objectives To assess the association between adherence to MD and risk of RA in a general population cohort. Methods The E3N cohort study (Etude Epidemiologique aupres des femmes de la Mutuelle generale de l’Education Nationale) is a French prospective cohort of 98,995 healthy women included in 1990-91 and followed since then (median follow-up of 28 years). Among women who completed a food-frequency questionnaire, we calculated the modified MD score (from 0 to 9) according to the consumption status of nine food components. Incident RA cases were detected using a validation process using a specific validation questionnaire and a drug reimbursement database. Hazard ratios (HRs) and 95% confidence intervals (CIs) for incident RA were estimated using Cox proportional hazards regression models with age as the time scale, and adjusting for known risk factors of RA and potential confounders. Because of the known importance of smoking on RA risk, we performed analyses adjusted and stratified on the smoking status. Results Among 62,630 women, 480 validated incident RA cases were diagnosed after a mean (± standard deviation) of 11.7 (± 5.9) years after the food-frequency questionnaire. In the whole population, high adherence to MD was not associated with a decreased risk of RA (HR for a 6-9 vs. 0-3 score = 0.86, 95% CI: 0.68−1.09, Plinear trend = 0.11). However, among ever-smoking women (current or past smokers), high adherence to MD was associated with a decreased risk of RA (HR for a 6-9 vs. 0-3 score = 0.77, 95% CI: 0.53−1.05; Plinear trend = 0.025), while there was no association in non-smokers (HR for a 6-9 vs. 0-3 score = 0.98, 95% CI: 0.70−1.38, Plinear trend = 0.90). Conclusion High adherence to a MD could reduce RA risk in ever-smoking women. Further studies are needed to confirm our findings. Acknowledgement We would like to thank the Foundation for Research in Rheumatology (FOREUM) and the French Rheumatology Society (SFR) for their financial support. Disclosure of Interests Yann Nguyen: None declared, Carine Salliot: None declared, Amandine gelot: None declared, Juliette Gambaretti: None declared, Xavier Mariette Grant/research support from: Servier, Consultant for: AstraZeneca, Bristol-Myers Squibb, GlaxoSmithKline, Janssen, Pfizer, UCB Pharma, Marie-Christine Boutron-Ruault: None declared, Raphaele Seror: None declared