SUN-621 Body Weight and Body Composition in Patients with Chronic Pancreatitis Are Associated with Islet Function After Total Pancreatectomy and Islet Cell Transplantation

Abstract

Background: Total pancreatectomy with islet autotransplant (TPIAT) is done in patients with chronic pancreatitis to treat intractable pain. In TPIAT, islets are isolated after pancreatectomy and infused into the liver via the portal vein to mitigate post-operative diabetes. Outcomes vary, with ≥60% needing exogenous insulin supplementation to maintain normoglycemia. The current study’s aim was to determine if pre-surgical body composition is associated with islet function and insulin sensitivity after TPIAT. Methods: We characterized body weight and composition as related to insulin sensitivity and dependence and diabetes outcome in 88 adults who underwent TPIAT for chronic pancreatitis at the University of Minnesota. At baseline, 12 and 18 months after TPIAT, insulin independence was assessed; metabolic testing used mixed meal tolerance testing and frequent sample intravenous glucose tolerance testing. Body composition was measured by Dual X-ray absorptiometry (DXA). Statistical analyses used linear and logistic regression. Results: At baseline, mean age was 39.9 (SD 11.1) years. 9.1% were underweight (BMI<18.5 kg/m2), 45.5% normal weight (BMI=18.5–24.9), 22.7% overweight (BMI=25–29.9) and 22.7% obese (BMI≥30). Islet equivalent per kg did not differ between body weight categories (p=0.17). Overweight/obese patients had higher peak and AUC c-peptide and lower insulin sensitivity index, as expected. Compared to baseline, android to gynoid fat ratio was lower at 12 (0.80 vs 0.88; p=0.012) and 18 months (0.81 vs 0.88; p=0.041), and lean mass was lower at 18 months (38848 vs 42338 kg; p=0.029). Baseline body weight was positively associated with acute insulin response to glucose (AIRg) at 12 months (effect size 38.5, SE 17.1 mU/L/min; p=0.029) and 18 months (38.3, SE 18.5 mU/L/min; p=0.045), while baseline lean mass was inversely associated with AIRg at 12 (p=0.01) and 18 months (p=0.033). Baseline body weight was positively associated, and fat mass inversely associated with disposition index (Di; islets’ ability to secrete insulin normalized to insulin resistance) at 18 months (p=0.019 for both).Percent body fat and percent gynoid fat predicted Sg (glucose effectiveness index, i.e., ability of glucose to promote its own disposal and inhibit hepatic glucose production absent an incremental insulin effect) at 18 months (p=0.042 and p=0.019, respectively). Insulin independence at 12 and 18 months was not significantly associated with baseline body weight or body composition. Conclusions: Overweight/obesity is common in patients with chronic pancreatitis. After TPIAT, patients had lower muscle mass and A/G ratio. Preoperative body weight and composition were associated with islet function but not insulin independence after TPIAT surgery.