Antimalarial Drug May Reduce Diabetes Risk in RA Patients

PITTSBURGH, July 10 -- The risk of developing diabetes decreased 38% among rheumatoid arthritis patients taking the antimalarial drug hydroxychloroquine (Plaqueril), according to a preliminary study.

This reduced risk at a mean of 3.1 years, compared with similar patients not taking the drug, was still greater for patients who took the drug for more than four years. Mary Chester M. Wasko, M.D., of the University of Pittsburgh, and colleagues reported in the July 11 issue of the Journal of the American Medical Association

These patients had a 77% reduced risk compared with patients who had never taken the drug, the investigators reported.

The dose-related findings came from a prospective, multicenter observational study of 4,905 adults with rheumatoid arthritis. According to self-reports, 1,808 had taken hydroxychloroquine and 3,097 had never taken the drug.

The patients, with no prior diagnosis or treatment for diabetes, were recruited from seven outpatient university-based and community-based rheumatology practices in North America, with 21.5 years of follow-up (January 1983 through July 2004).

During the observation period, incident diabetes was reported by 54 patients who had taken hydroxychloroquine and by 171 patients who had never taken the drug. Incidence rates were 5.2 per 1,000 patient-years of observation compared with 8.9 per 1,000 patient-years of observation, respectively (P

Although this study showed a reduction specifically in rheumatoid arthritis, these findings may also be expected to occur in patients without rheumatoid arthritis, Dr. Wasko said. The beneficial changes in glucose metabolism and insulin sensitivity reported among patients with lupus, those with type 2 diabetes, and in animal models "suggest that these changes are not specific to rheumatoid arthritis," she said.

Limitations of the study included possible misclassification of some patients who reported no prior use of hydroxychloroquine. The racial homogeneity of the cohort (almost 90% white) may limit the generalizability of these findings, the researchers added.

"As quality of life and life expectancy improve for patients with rheumatoid arthritis, and health care costs escalate, the use of inexpensive, safe therapies that have multiple beneficial effects is attractive," the researchers wrote.

Dr. Wasko reported being a consultant to Centocor in cardiovascular outcomes in ongoing rheumatoid arthritis clinical trials and has been a coinvestigator in a Merck-sponsored study of thromboembolic markers in rheumatoid arthritis and osteoarthritis.

Dr.Wasko has received contractual reimbursement as site principal investigator for an Aventis-sponsored clinical trial of leflunomide in rheumatoid arthritis, ending in November 2002. Dr.Wasko also reported receiving contractual reimbursement as site principal investigator for rheumatoid arthritis clinical trials sponsored by Centocor, Roche, Human Genome Sciences, and Novartis. No other authors reported disclosures.

This study was supported by the Arthritis Foundation of Western Pennsylvania, the National Arthritis Foundation, the National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, and the Intramural Research Program, National Institute of Arthritis and Musculoskeletal and Skin Diseases.