61st EASD Annual Meeting of the European Association for the Study of Diabetes SO 019 It's beta cell replacement time: 402 - Continuous glucose monitoring and assessment of islet function in autologous islet transplantation after total pancreatectomy for pancreatic neoplasia: preliminary data from the Verona cohort

Background and aims: Total pancreatectomy with autologous islet transplantation (TPAIT) has been proposed as an alternative to high-risk pancreatic anastomosis after pacreaticoduodenectomy for prevention of surgical complications, while maintaining low risks to develop brittle pancreatogenic diabetes. However, few studies have investigated the relationship between continuous glucose monitoring (CGM) profiles and TPAIT outcomes. Materials and methods: Between September 2023 and March 2025, 10 patients with pancreatic neoplasia underwent TPAIT (males/females 5/5, age 60 [IQR 55-68] years, islet infusion 1912 [IQR 1724 - 3074] IEQ/kg) at the Verona University Hospital. At 3 (n=10), 6 (n=8) and 12 months (n=6) after TPAIT, CGM profiles were collected, and islet metabolic function was assessed through the most recent Igls-derived criteria and BETA-2 score. CGM metrics were compared across Igls categories. Results: Igls criteria layered islet function across available time points (n=24) as optimal (n=10), good (n=6), marginal (n=7) and failure (n=1). BETA-2 score progressively fell across the 4 Igls categories (median [IQR] 19.4 [17.7-19.8], 13.6 [11.8-15.7], 5.3 [2.2-11.9], 1.42, respectively; p=0.001). In CGM profiles, optimal vs good and marginal outcomes showed significantly higher time in range (TIR) and in tight range (TITR) (TIR: 97.0% vs 75.5%, p 0.004, and 70.0%, p 0.005; TITR: 86.5% vs 41.0%, p=0.004, and 40.0%, p=0.005), and lower time above range (TAR) and glycemia risk index (GRI) (TAR: 1.5% vs 24.5%, p=0.003, and 29.0%, p <0.001; GRI: 4.0 vs 22.0, p=0.007, and 32.0, p=0.009). Spearman’s correlation analyses (rho) confirmed inverse associations of Igls stages with TIR and TITR (-0.566, p=0.005 and -0.684, p<0.001, respectively) and positive associations with TAR, CV and GRI (0.598, p=0.003; 0.460, p=0.025; 0.508, p=0.013, respectively). TIR, TITR, TAR, CV and GRI showed consistent associations also with BETA-2 score (0.813, 0.859, -0.828, -0.688, -0.735, all p<0.001, respectively), and with infused islet equivalents (0.502, p=0.013; 0.586, p=0.003; -0.585, p=0.003; -0.530, p=0.009; -0.456, p=0.026, respectively). Conclusion: Optimal islet function after TPAIT, as assessed by Igls or BETA-2 score, was associated with longer time spent in euglycemia and lower time spent in hyperglycemia, as documented by CGM. Several CGM metrics, including TIR, TITR, TAR and GRI, were strongly and consistently related with Igls and BETA-2 score, thereby possibly validating their roles of good clinical indicators of islet glucose competence.