Body Composition is Associated with Islet Function after Pancreatectomy and Islet Autotransplantation for Pancreatitis

Context: Body composition in total pancreatectomy with islet autotransplantation (TPIAT) has never been studied. Objective: Determine whether presurgical body composition is associated with islet function and insulin sensitivity after TPIAT. Methods: In 88 adults undergoing TPIAT (median age 41.0 years, IQR 32.8-48.0), beta-cell function and insulin sensitivity were assessed using mixed meal tolerance test and frequent sample intravenous glucose tolerance test before surgery and 12 and 18 months afterward. Body composition was measured by dual x-ray absorptiometry. Analyses used linear and logistic regression. Results: Before surgery, 8 individuals (9.1%) were underweight, 40 (45.5%) normal weight, 20 (22.7%) overweight, and 20 (22.7%) obese. Overweight/obese patients had higher area under the curve C-peptide and lower insulin sensitivity index. Baseline body weight was positively associated with first-phase insulin secretion (AIRg) at 12 months (average 38.5 [SE 17.1] mU/L/min higher per extra kg; P=0.03) and 18 months (38.3 [18.5]; P=0.04), while baseline lean mass was inversely associated with AIRg at 12 months (-0.05 [0.02] per extra kg; P=0.01) and 18 months (-0.05 [0.02]; P=0.03). Percent gynoid fat was inversely associated with disposition index at 18 months (-206.0 [97.2] per extra percent; P=0.04). Percent body fat and percent gynoid fat were associated with glucose effectiveness index at 18 months (1.9×10-3 [0.9×10-3] per extra percent; P=0.04 and -1.96×10-3 [0.8×10-3]; P=0.02, respectively). Insulin independence was not significantly associated with body weight or composition. Conclusions: Half of these chronic pancreatitis patients were overweight/obese; underweight was uncommon. Preoperative body weight and composition were associated with islet function but not insulin independence after TPIAT.