To the Editor: In their multicenter study of the association between treatment with hydroxychloroquine and the risk of diabetes mellitus, Dr Wasko and colleagues1 followed up a large cohort of patients with rheumatoid arthritis for 21.5 years. After adjustment for diabetes risk factors and prednisone use, the authors concluded that treatment with hydroxychloroquine was associated with a reduced risk of developing diabetes. The use of prednisone was evaluated as “ever” or “never” and the percentage of time using the drug during the observation period was calculated.
Di Comite G, Rossi CM. Risk of Diabetes in Patients With Rheumatoid Arthritis Taking Hydroxychloroquine. JAMA. 2007;298(20):2368-2370. doi:10.1001/jama.298.20.2368-b