Many clinical islet transplant programs have body mass index (BMI) and/or weight based thresholds for eligibility. Large subjects may require higher islet mass to reliably achieve insulin independence. However, for long term graft function and protection from hypoglycemia, data supporting a BMI based exclusion is lacking.

Methods: Subjects undergoing islet transplantation at a single center, between 1999 and 2017 were included. Graft survival as measured by C-peptide positivity from last CIT was compared between recipients with BMI<30 kg/m2 (n=237, 24.8±2.8 kg/m2) and BMI >30 kg/m2 (n=24, mean±SD 31.9±2.1 kg/m2) pre-transplant.

Results: Apart from BMI and weight (BMI<30 vs. BMI>30, 70.9±11.3 kg vs. 82.8±9.5 kg; P<0.05) there were no difference between groups in terms of baseline recipient characteristics, including in daily insulin dose (0.58±0.16 U/kg vs. 0.59±0.18 U/kg; P=0.34). Both groups received similar total number of islet infusions (2.4±0.9 and 2.3±0.6, p=0.6), total islet equivalents (1 053 022±471 532 vs. 1 182 498±366 368, P=0.19) and total islet equivalents per recipient body weight (15 208±6 373 IE/kg vs. 14 120±5 041 IE/kg, P=0.42). Long term C-peptide survival was not different between groups (P=0.18).

Conclusion: T1D patients with BMI>30 appear to have similar islet mass requirements and graft survival compared to those with BMI<30. This likely reflects careful selection of smaller (weight <90 kg), insulin sensitive (<0.6 U/kg) subjects with only class I obesity. Given the prevalence of obesity in T1D, future studies should evaluate the roles of obesity, weight and insulin sensitivity to ensure rational and equitable access to transplantation.


A. Lam: None. K.J. Potter: None. S. Forbes: None. S. Imes: None. A.J. Malcolm: None. A. Haqq: None. A. Shapiro: Consultant; Self; Viacyte, Inc., Protokinetix. P.A. Senior: Consultant; Self; Abbott, AstraZeneca. Research Support; Self; AstraZeneca, Prometic Life Sciences Inc., Novo Nordisk Inc., Sanofi. Consultant; Self; Eli Lilly and Company. Speaker's Bureau; Self; Eli Lilly and Company, Novo Nordisk Inc.. Consultant; Self; Novo Nordisk Inc., Janssen Pharmaceuticals, Inc.. Speaker's Bureau; Self; Janssen Pharmaceuticals, Inc.. Consultant; Self; Boehringer Ingelheim Pharmaceuticals, Inc.. Speaker's Bureau; Self; AstraZeneca, Merck & Co., Inc., Abbott. Research Support; Self; Viacyte, Inc..

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