IL-1 inhibition improves insulin resistance and adipokines in rheumatoid arthritis patients with comorbid type 2 diabetes: An observational study

Abstract

Recently, it has been shown that some well-known pathogenic mediators in rheumatoid arthritis (RA), such as interleukin-1β (IL-1β) and tumor necrosis factor (TNF), could play a pathogenic role in insulin resistance and (IR) and type 2 diabetes (T2D).In this 6-month longitudinal study, we aimed at investigating if the inhibition of IL-1 or TNF is associated with an improvement of IR in RA patients with comorbid T2D and the possible effects on selected serum adipokines. RA patients with comorbid T2D were recruited among those undergoing treatment with anakinra (ANA) or with TNF inhibitor (TNFi). The 1998-updated version of the Homeostasis Model Assessment (HOMA2) was used to calculate surrogate indexes of IR (HOMA2-IR) and steady-state beta cell function (%B) from fasting values of glucose and C-peptide. Glucagon, adiponectin, adipsin, leptin, and resistin were also measured. All these parameters were collected at baseline, after 3 and 6 months of treatment.ANA-treated patients showed a significant improvement in HOMA2-%β, HOMA2-IR, and glucagon. In TNFi-treated patients, no significant difference was observed analyzing these metabolic parameters. Adipsin and resistin decreased after 6 months in ANA-treated patients whereas, no difference was recognized analyzing adiponectin and leptin. In TNFi-treated patients, leptin and resistin significantly increased, whereas no difference was found analyzing adiponectin and adipsin, during the follow-up.Our data may suggest a beneficial effect of IL-1 inhibition on measures of metabolic derangement in RA-associated T2D. If further confirmed by larger studies, IL-1 targeting therapies may represent a tailored approach in these patients.

Figure 1

Study design. A 6-month longitudinal cohort study was designed, in which RA patients with comorbid T2D were consecutively recruited among those undergoing treatment with anakinra and age- and gender-matched RA patients undergoing treatment with TNFis.

Figure 2

Glucose homeostasis assessment before and after treatment. Different parameters assessing glucose homeostasis before and after treatment with anakinra (ANA) and tumor necrosis inhibitor (TNFi) are reported. (A) HOMA2-IR, homeostasis model assessment – insulin resistance; (B) HOMA2-%BETA, homeostasis model assessment – estimated steady-state β cell function; (C) glucagon.

Figure 3

Adipokines assessment before and after treatment. Selected adipokines are reported before and after treatment with anakinra (ANA) and tumor necrosis inhibitor (TNFi). (A) adiponectin; (B) adipsin; (C) leptin; (D) resistin.