Serum selenium, serum alpha-tocopherol, and the risk of rheumatoid arthritis

Antioxidant micronutrients have been hypothesized to provide protection aga inst rheumatoid arthritis. We investigated. serum selenium and serum alpha- tocopherol for their prediction of subsequent development of rheumatoid art hritis in a case-control study nested within a Finnish cohort of 18,709 adu lt men and women who had neither arthritis nor a history of it at the basel ine examination in 1973-1978; by late 1989, 122 had developed rheumatoid ar thritis. Of the incident cases, 34 were rheumatoid factor-negative. Three c ontrols per each incident case were individually matched for sex, age, and municipality. Serum selenium and alpha-tocopherol concentrations were measu red from stored serum samples collected at baseline. Serum selenium was inv ersely related to subsequent occurrence of rheumatoid factor-negative but n ot rheumatoid factor-positive rheumatoid arthritis. The relative risks, adj usted fur smoking and serum total cholesterol, for the highest relative to the lowest tertile of serum selenium, were 0.16 [95% confidence interval (C I) = 0.04-0.69] for rheumatoid factor-negative and 0.96 (CI = 0.49-1.90) fo r rheumatoid factor-positive rheumatoid arthritis. During the first 10 year s of follow-up, the relative risk for rheumatoid arthritis for the highest compared with the lowest tertile of serum alpha-tocopherol was 0.44 (CI = 0 .19-0.99). No association was found for longer follow-up periods. Low selen ium status may be a risk factor for rheumatoid factor-negative rheumatoid a rthritis, and low alpha-tocopherol status may be a risk factor for rheumato id arthritis independently of rheumatoid factor status.