DMARDs may reduce diabetes risk for patients with RA, psoriasis

Disease-modifying antirheumatic drugs (DMARDs) may lower diabetes (DM) risk in patients with rheumatoid arthritis (RA) or psoriasis, according to a study published in the June 22 issue of the Journal of the American Medical Association.

Researchers examined the relationship between newly recorded DM among 121,280 patients with a diagnosis of RA or psoriasis on at least 2 visits and their use of a variety of disease-modifying antirheumatic drugs (DMARDs). Administrative data from patients enrolled in 2 large health insurance programs-1 in Canada and 1 in the United States - were analyzed over a mean follow-up time of 5.8 months from the first DMARD prescription after study eligibility. Study duration was from January 1996 through June 2008, and patients were observed until they experienced an outcome, died, disenrolled from the health plan, or follow up ended.

To measure newly diagnosed DM and the use of a DM-specific medication, 4 mutually exclusive groups of DMARDs were defined:

(1) tumor necrosis factor (TNF) inhibitors with or without any other nonbiologic DMARDs;
(2) methotrexate without TNF inhibitors or hydroxychloroquine;
(3) hydroxychloroquine without TNF inhibitors or methotrexate; or
(4) other nonbiologic DMARDs without TNF inhibitors, methotrexate, or hydroxychloroquine.

The investigators concluded that the use of a TNF inhibitor or hydroxychloroquine but not methotrexate was associated with a reduced risk of DM compared with other nonbiologic DMARDs among patients with RA or psoriasis.

The researchers found that the incidence rate of DM was reduced in users of TNF inhibitors and hydroxychloroquine, compared with other nonbiologic DMARDs. They also found a suggestion of a reduced risk with methotrexate. The findings were consistent across a variety of sensitivity analyses, the authors noted.

“Considering these results in light of prior findings regarding improved insulin and glucose metabolism and reduced DM risk with hydroxychloroquine and TNF inhibitors, there is evidence suggesting a possible role for DMARDs and immunosuppression in DM prevention,” the authors wrote, noting that their findings should be considered hypothesis-generating and that future studies might address ability of these agents to prevent DM among patients with systemic inflammatory disorders.