Use of biologic or targeted-synthetic disease-modifying anti-rheumatic drugs and risk of diabetes treatment intensification in patients with rheumatoid arthritis and diabetes mellitus

Objectives. Given that RA treatment might affect the severity of diabetes mellitus (DM), we compared the risk of DM treatment intensification in patients with both RA and DM newly initiating a biologic DMARD or tofacitinib. Methods. Using claims data from the IBM MarketScan database (2005-2016), we identified patients aged >= 18 years with RA who initiated abatacept, a TNF inhibitor (TNFi), rituximab, tocilizumab or tofacitinib. Patients were required to have type 1 or type 2 DM and to use at least one antidiabetic drug at baseline. We assessed DM treatment intensification (i.e. addition of a new insulin or non-insulin antidiabetic medication). We also assessed non-insulin antidiabetic medication switching events. Results. We included 10 019 patients with RA and DM initiating a biologic DMARD or tofacitinib. Baseline insulin use was the highest in rituximab initiators (44%) and lowest in tofacitinib initiators (35%). The incidence rate per 1000 person-years for DM treatment intensification ranged from 148.2 (tofacitinib) to 198.0 (rituximab). The risk of DM treatment intensification was similar between abatacept and TNFi [hazard ratio (HR) 0.97, 95% CI: 0.82, 1.15], rituximab (HR 0.99, 95% CI: 0.79, 1.23) and tocilizumab (HR 0.94, 95% CI: 0.74, 1.19), but lower for tofacitinib compared with abatacept (HR 0.67, 95% CI: 0.50, 0.90). The risk of non-insulin DM treatment switching was not different between abatacept and other biologic DMARDs. Conclusion. In patients with both RA and DM, we found no difference in the risk of DM treatment switching or intensification after initiating abatacept vs TNFi, rituximab and tocilizumab, whereas the risk appeared to be lower for tofacitinib.