Sustained Effects of Interleukin-1 Receptor Antagonist Treatment in Type 2 Diabetes

OBJECTIVE - Interleukin (IL)-1 impairs insulin secretion and induces P-cell apoptosis. Pancreatic beta-cell IL-1 expression is increased and interleukin-1 receptor antagonist (IL-1Ra) expression reduced in patients with type 2 diabetes. Treatment with recombinant IL-1Ra improves glycemia and P-cell function and reduces inflammatory markers in patients with type 2 diabetes. Here we investigated the durability of these responses. RESEARCH DESIGN AND METHODS - Among 70 ambulatory patients who had type 2 diabetes, A1C >7.5%, and BMI >27 kg/m(2) and were randomly assigned to receive 13 weeks of anakinra, a recombinant human IL-1Ra, or placebo, 67 completed treatment and were included in this double-blind 39-week follow-up study. Primary outcome was change in P-cell function after anakinra withdrawal. Analysis was done by intention to treat. RESULTS - Thirty-nine weeks after anakinra withdrawal, the proinsulin-to-insulin (PI/I) ratio but not stimulated C-peptide remained improved (by -0.07 [95% CI -0.14 to -0.02], P = 0.011) compared with values in placebo-treated patients. Interestingly, a subgroup characterized by genetically determined low baseline IL-1Ra serum levels maintained the improved stimulated C-peptide obtained by 13 weeks of IL-1Ra treatment. Reductions in C-reactive protein (-3.2 mg/l [-6.2 to -1.1], P = 0.014) and in IL-6 (-1.4 mg/l [-2.6 to -0.3], P = 0.036) were maintained until the end of study. CONCLUSIONS - IL-1 blockade with anakinra induces improvement of the PIA ratio and markers of systemic inflammation lasting 39 weeks after treatment withdrawal.