137-LB: Modified Personal Glycemic State Model Predicts the Need for Islet Transplantation in Human

Abstract

Continuous glucose monitoring (CGM) has become a valuable tool for assessing glycemic control. The personal glycemic state (PGS)1 is a mathematical model that considers 5 CGM data elements (mean blood glucose, percent time in range, glucose variability percentage, and frequency of moderate and severe hypoglycemia) equally to generate a score representing the degree of metabolic control. Our adapted personal glycemic state for islet transplant (PGSFIT) targets normoglycemia in islet transplantation by limiting the percent time in range to 70-140mg/dl instead of commonly used 70-180mg/dl, and uses weighted components without limiting the influence of any individual component on the total score. This allowed us to account for T1D patients keeping blood glucose high to avoid hypoglycemia or low to avoid long term complications despite increased hypoglycemia. Using PGS and PGSFIT to analyze glycemic control in 16 subjects with T1D post allogenic islet transplantations showed concordance in classifying the glycemic control as acceptable (PGS/PGSFIT <15) or unacceptable (≥15) in 88% of the cases when variability was low (standard deviation of PGS components ≤ 0.1), and both PGSFIT and PGS models had excellent correlation with fasting c-peptide results. In contrast, when variability was high (standard deviation of PGS components > 0.1), 71% of patients deemed clinically suitable for repeat transplant had PGSFIT score ≥15 but only 14% had PGS score ≥15. In patients who had not yet received their final islet infusion, high parameter variability and PGSFIT ≥15 was associated with lower fasting C-peptide compared to patients with high parameter variability and PGSFIT ≤15 who received the maximum therapeutic dose. PGSFIT significantly improved after repeat transplant in patients with high PGSFIT and high component variability. These results suggest PGSFIT may also be used to identify subjects suitable for first islet transplant. Disclosure C. Orr: None. J. Hacker-stratton: None. M. El-shahawy: None. E. Forouhar: None. K. Omori: None. M. Qi: None. F. R. Kandeel: None. Funding National Institutes of Health (U24DK098085)