We assessed whether disease activity was associated with dietary habits, nutritional status, adipokines, and oxidative stress in patients with rheumatoid arthritis.

The subjects were 37 patients with RA. The assessment of the nutritional status included anthropometric and biochemical parameters. A food-frequency questionnaire and a 3-d diet record to assess dietary intake were used. The serum levels of adipokines and oxidative stress markers in sera and saliva were measured. The disease activity was determined using the 28 Disease Activity Score (DAS28). We divided the subjects into high (DAS28 ≥3.2) and low (DAS28 <3.2) disease activity groups.

The serum leptin and albumin levels were significantly lower, whereas the inflammatory markers were increased, in the high disease activity group. The dietary intake assessment showed a lower intake of fish oil and a lower ratio of monounsaturated fatty acid intake in the high disease activity group. There was a negative correlation between the DAS28 and the dietary intake of the ratio of monounsaturated fatty acid to total fatty acid intake. The serum oxidative stress marker (reactive oxygen metabolites) showed a positive correlation to the DAS28. The salivary reactive oxygen metabolites also correlated with C-reactive protein and serum reactive oxygen metabolites.

Altered serum adipokine levels with decreased albumin may reflect the deterioration that is associated with rheumatoid arthritis. An increased oxidative stress was observed in sera and saliva. Intakes of ω-3 polyunsaturated fatty acids, fish oil, and monounsaturated fatty acid seem to affect disease activity and may have beneficial effects by decreasing inflammation.