Study of the Relationship between disease severity, quality of life and serum levels of inflammatory factors and total antioxidant capacity with dietary inflammatory index and dietary total antioxidant capacity in patients with rheumatoid arthritis

Abstract

Abstract Objective: Inflammation and oxidative stress are two very important factors in the onset and progression of rheumatoid arthritis (RA). Meanwhile, food and nutrition play important roles in controlling inflammation and oxidative stress. The aim of this study was to investigate the relationship between disease severity, quality of life and the levels of inflammatory factors and total serum antioxidant capacity (TAC) with inflammatory index and dietary antioxidant capacity in patients with RA. Methods: The present study Was a cross-sectional observational study that targets subjects with RA. Participants in this study included 100 people with RA and 100 apparently healthy people in the age range of 20-70. Food intake was assessed using a food frequency questionnaire; and (dTAC) and dietary inflammatory index (DII) were calculated using its data. Serum levels of inflammatory factors including TNF-α, hs-CRP and TAC were measured using ELISA kits. Results: DII and dietary TAC scores were higher (P = 0.002) and lower (P = 0.07) in RA patients compared to control group, respectively; However, no significant difference was observed in mean of dTAC between the groups. Evaluation of the relationship between serum hs-CRP, TNF-α and RF levels with DII quarters showed that an increase in DII score was associated with increase in inflammation. Evaluation of the relationship between serum TAC levels and dTAC showed no significant relationship between the variables. dTAC was not significantly associated with disease severity; However, DII was directly associated with increased disease severity (P = 0.001). The results of the present study showed that for each unit increase in DII score, the severity of the disease increases by 1.11 units. There was also a direct and significant relationship between serum hs-CRP levels and disease severity. On the other hand, the correlation between inflammatory factors and serum TAC with quality of life and disease severity showed that high levels of TNF-α and hs-CRP were associated with decreased quality of life and increased disease severity and the correlation between serum TAC levels and quality of life only was significant. Increased serum TAC has been associated with decreased quality of life. Mean serum TNF-α, hs-CRP and TAC were higher in RA subjects than control group. Conclusion: The results of the present study showed that diets with low DII potential can play a significant role in improving the severity of RA. Therefore, based on the results, interventional studies with low DII diets are recommended to reduce the severity of the disease in these patients.