Abstract
BACKGROUND: A consistent connection has been increasingly reported between rheumatoid arthritis (RA), insulin resistance (IR), and type 2 diabetes (T2D). The β-cell apoptosis induced by pro-inflammatory cytokines, which could be exaggerated in the context of RA, is associated with increased expression pro-apoptotic proteins, which is dependent on JAnus Kinase/Signal Transducer and Activator of Transcription (JAK/STAT) activation. On these bases, we aimed to evaluate if the administration of tofacitinib, a potent and selective JAK inhibitor, could simultaneously improve glycaemic parameters and inflammatory markers in patients with RA and comorbid T2D. METHODS: The primary endpoint was the change in the 1998-updated homeostatic model assessment of IR (HOMA2-IR) after 6 months of treatment with tofacitinib in RA patients with T2D. Consecutive RA patients with T2D diagnosis were included in this proof-of-concept, open, prospective, clinical study, which was planned before the recent emergence of safety signals about tofacitinib. Additional endpoints were also assessed regarding RA disease activity and metabolic parameters. RESULTS: Forty consecutive RA patients with T2D were included (female sex 68.9%, mean age of 63.4 ± 9.9 years). During 6-month follow-up, a progressive reduction of HOMA2-IR was observed in RA patients with T2D treated with tofacitinib. Specifically, a significant effect of tofacitinib was shown on the overall reduction of HOMA2-IR (β = - 1.1, p = 0.019, 95%CI - 1.5 to - 0.76). Also, HOMA2-β enhanced in these patients highlighting an improvement of insulin sensitivity. Furthermore, although a longer follow-up is required, a trend in glycated haemoglobin reduction was also recorded. The administration of tofacitinib induced an improvement in RA disease activity, and a significant reduction of DAS28-CRP and SDAI was observed; 76.8% of patients achieved a good clinical response. In this study, no major adverse events (AEs) were retrieved without the identification of new safety signals. Specifically, no life-threatening AEs and cardiovascular and/or thromboembolic events were recorded. CONCLUSIONS: The administration of tofacitinib in RA with T2D led to a simultaneous improvement of IR and inflammatory disease activity, inducing a "bidirectional" benefit in these patients. However, further specific designed and powered studies are warranted to entirely evaluate the metabolic effects of tofacitinib in RA patients with T2D.