Differential Impact of Weight Loss and Glycemic Control on Inflammasome Signaling
Luca Antonioli, Diego Moriconi, Stefano Masi, Dario Bottazzo, Carolina Pellegrini, Matteo Fornai, Marco Anselmino, Ele Ferrannini, Corrado Blandizzi, Stefano Taddei, Monica Nannipieri
Abstract
OBJECTIVE: Interleukin (IL)-1β is involved in obesity-associated inflammation and in the pathogenesis of type 2 diabetes (T2D) mellitus. Our aim was to correlate serum IL-1β and caspase-1 levels with weight loss, glucose metabolism, and insulin resistance (IR) after bariatric surgery. METHODS: A total of 32 patients with morbid obesity and T2D (Ob-T2D) and 29 patients with morbid obesity and normal glucose tolerance (Ob-NGT), treated by Roux-en-Y gastric bypass, were studied before and 1 year after surgery. Sixteen healthy individuals served as a control (HC) group. IR was assessed by the oral glucose insulin sensitivity method. Plasma IL-1β levels and caspase-1 were measured. RESULTS: Presurgery BMI was similar in Ob-NGT and Ob-T2D. IR was progressively impaired in Ob-NGT and Ob-T2D (P < 0.0001). Fasting plasma IL-1β and caspase-1 levels were lower in HCs than in patients with Ob-NGT or Ob-T2D (P < 0.02; P = 0.05), and both were inversely correlated with IR (P = 0.01; P = 0.02). After surgery, BMI decreased and IR improved to a similar extent in Ob-NGT and Ob-T2D (P < 0.0001). Plasma caspase-1 concentrations normalized in both groups (P < 0.0001), whereas plasma IL-1β levels normalized only in Ob-NGT. CONCLUSIONS: Plasma IL-1β and caspase-1 levels were inversely correlated with IR. Caspase-1 levels normalized after weight loss, whereas IL-1β normalized only in people without T2D, suggesting the persistence of a systemic inflammatory condition in people with T2D.