Effect of vitamin E supplementation in rheumatoid arthritis: a systematic review and meta-analysis

Association Between Composite Dietary Antioxidant Index and the Risk of Endometriosis-Related Rheumatoid Arthritis in Women of Childbearing Age: A Cross-Sectional Study Based on the National Health and Nutrition Examination Survey Database

Purpose

To evaluate the association between Composite Dietary Antioxidant Index (CDAI) and the risk of endometriosis (EM)-related rheumatoid arthritis (RA) in women of childbearing age.

Methods

Using the data from the National Health and Nutrition Examination Survey database, this cross-sectional study included women of childbearing age. The CDAI was obtained by summing the standardized Z-values of the dietary intakes. EM was diagnosed based on a questionnaire-based survey. The outcome of this study was the presence of RA, which was defined by a questionnaire. The associations of CDAI and EM with the risk of RA were determined using weighted logistic analysis. Additive interaction was evaluated using the relative excess risk due to interaction (RERI), the attributable proportion due to interaction (AP), and the synergy index (S).

Results

In total, 3803 patients were included, of which 74 patients (1.99%) were with RA. A lower CDAI [odds ratio (OR): 1.85, 95% confidence interval (CI): 1.12 to 3.04, P= 0.015] and the presence of EM (OR: 3.05, 95% CI: 1.19 to 7.81, P= 0.023) was associated with the risk of RA. The result demonstrated an additive interaction of a lower CDAI and the presence of EM on the risk of RA (OR: 6.19, 95% CI: 2.33 to 16.43, P <0.001, P of trend =0.007). Nevertheless, there was no significant additive interaction after being assessed by the RERI, AP, and S. However, a joint effect of a lower CDAI and EM on the risk of RA (OR: 3.94, 95% CI: 1.35 to 11.51, P= 0.013) was observed.

Conclusion

Our study identified EM, and lower CDAI, was related to the risk of RA. Lower CDAI score was also associated with the risk of EM-related RA. This study indicates the importance of antioxidant intake in daily diet for the management of EM-related RA.

Lifestyle Factors and Their Influence on Rheumatoid Arthritis: A Narrative Review

In recent years, a possible association of lifestyle factors with rheumatoid arthritis (RA) has attracted increasing public interest. The aim of this review is to provide an overview of the extent and the limitations of current evidence regarding lifestyle factors and RA. The PubMed medical database was screened for epidemiological and prospective studies investigating the contribution of lifestyle factors to the development and the course of the disease. Large epidemiological studies have identified smoking, unhealthy diet and adiposity, as well as a low educational level and low socioeconomic status, as factors that increase the incidence of RA. In addition, several lifestyle habits influence the response of RA to antirheumatic drugs. Among others, smoking, obesity and poor physical activity are associated with a worse treatment outcome. Methodological problems often impair firm conclusions with respect to the causal role of these factors in the risk and the course of RA. However, current evidence is sufficient to recommend a healthy diet, the prevention of obesity, the cessation of smoking and the maintenance of a high level of physical activity to support the effectivity of modern antirheumatic medication.