Excessive Weight Gain After Pancreas Transplant: Transitioning from Type 1 to Type 2 Diabetes?

AIM: Excessive weight gain (EWG) after pancreas transplantation may increase the risk of post-transplant diabetes mellitus and metabolic syndrome. This study aimed to define the incidence, risk factors and the consequences of EWG after pancreas transplantation. METHODS: This was a single center review of 76 kidney-pancreas transplants performed on patients with type 1 diabetes between 9/2007 and 11/2013. Recipients with <1 year of follow-up or early graft loss were excluded. Immunosuppression included tacrolimus, ±mTOR inhibitor, ±prednisone. EWG was defined as >18% weight increase in the 1st year post-transplant, as this was the upper limit of the interquartile range of percent weight gain at 1 year. RESULTS: Demographics of the cohort included: 61% male, 57% Caucasian, 21% Hispanic, and 22% African American. Mean recipient age and BMI at transplant were 41±10 years and 25±4 kg/m2, respectively. The mean weight gain for all patients at 1 year post-transplant was 10.7±13.3%. The overall incidence of EWG at 1 year post-transplant was 28% (n=21). Using multivariate analyses, independent risk factors for EWG included Hispanic ethnicity (OR=8.8, p=0.01), BMI<24 at time of transplant (OR=7.5, p=0.01), and pre-transplant HgbA1c >7% (OR= 8.9, p=0.01). No individual maintenance immunosuppression agent conferred a greater risk of EWG. At 1-year post-transplant, recipients with EWG had higher triglyceride (148±71 vs 106±45 mg/dl, p=0.01) and cholesterol levels (208±41 vs 175±42 mg/dl, p=0.01). Although mean HgbA1c, c-peptide, and fasting plasma glucose did not differ significantly between groups, impaired glucose control (HbgA1c ≥ 6%) was more common in recipients with EWG (21% vs 7%, p=0.19). CONCLUSION: Almost one of 3 pancreas recipients experienced EWG within the 1st year post-transplant. Pre-transplant risk factors included Hispanic ethnicity, lower BMI and poor glucose control. At 1-year, recipients with EWG had higher lipid levels and showed a trend toward impaired glucose control. These data suggest that pancreas recipients with early EWG may develop risk factors for metabolic syndrome and type 2 diabetes.