Adherence to Antimalarial Therapy and Risk of Type 2 Diabetes Mellitus Among Patients With Systemic Lupus Erythematosus: A Population‐Based Study

• Published in: Arthritis care & research (2010) 2021-05, Vol.73 (5), p.702-706
• Main Authors: Salmasi, Shahrzad, Sayre, Eric C., Antonio Aviña‐Zubieta, J., Esdaile, John M., De Vera, Mary A.
• Format: Article
• Language: English
• Subjects: Diabetes; Diabetes mellitus (non-insulin dependent); Lupus; Population studies; Population-based studies; Systemic lupus erythematosus
• ISSN: 2151-464X; 2151-4658
• DOI: 10.1002/acr.24147

Objective To evaluate the association between adherence to antimalarials and type 2 diabetes mellitus (DM) in patients with systemic lupus erythematosus (SLE). Methods Using administrative health databases in British Columbia, Canada, we conducted a retrospective, longitudinal cohort study of patients with incident SLE and incident antimalarial use. We established antimalarial drug courses by defining a new course when a 90‐day gap is exceeded between refills and we calculated proportion of days covered (PDC) for each course. We categorized medication taking as: 1) adherent (PDC ≥0.90), 2) nonadherent (0 < PDC < 0.90), and 3) discontinuer (no drug). Type 2 DM outcomes were based on outpatient or inpatient visits, or antidiabetic medication use. We used multivariable Cox proportional hazards models with time‐dependent variables. Results Over a median of 4.62 years of follow‐up in our incident cohort of 1,498 patients with SLE (90.8% women), we recorded 140 incident cases of type 2 DM. Multivariable hazard ratios were 0.61 (95% confidence interval [95% CI] 0.40–0.93) for adherent and 0.78 (95% CI 0.50–1.22) for nonadherent, respectively, as compared to discontinuers. Conclusion Our findings of a protective effect of adherence to antimalarials in preventing type 2 DM provides further support for the importance of adherence to antimalarials to obtain the benefits of therapy.