Glycemic predictors of insulin independence after total pancreatectomy with islet autotransplantation

Context: Total pancreatectomy with islet auto transplantation (TPIAT) is a treatment for medically refractory chronic pancreatitis that can prevent postsurgical diabetes in some patients. Predictors of insulin independence are needed for appropriate patient selection and counseling. Objective: To explore glycemic predictors of insulin independence after TPIAT. Design: A prospective cohort of patients. Methods: We investigated 34 patients undergoing TPIAT from 2011-2016 at Johns Hopkins Hospital, all had a 75-g oral glucose tolerance test (OGTT) administered prior to their TPIAT. The primary outcome was insulin independence 1 year after TPIAT. Results: Ten of 34 (29%) patients were insulin independent 1 year after TPIAT. All patients with impaired fasting glucose and/or impaired glucose tolerance preoperatively were insulin dependent at 1 year. In age-adjusted regression analyses, fasting glucose # 90 mg/dL [odds ratio (OR) = 6.56; 1.11 to 38.91; P = 0.04], 1-hour OGTT glucose # 143 mg/dL (OR = 6.65; 1.11 to 39.91; P = 0.04), and 2-hour OGTT glucose # 106 mg/dL (OR = 11.74; 1.46 to 94.14; P = 0.02) were significant predictors of insulin independence. In receiver operating characteristic analyses, homeostatic model assessment of b-cell function (HOMA-b) was the most robust predictor of insulin independence [area under the curve (AUC) = 0.88; 0.73 to 1.00]. Conclusions: Normal preoperative glucose status and lower fasting and postchallenge OGTT glucose values are significant predictors of insulin independence after TPIAT. Higher islet function (HOMA-b) was the strongest predictor. OGTT testing may be a useful tool to aid in patient counseling prior to TPIAT and should be further investigated.