Pancreatic Exocrine Secretion and Weight Gain After Pancreas Transplantation

Weight gain after pancreas transplant is a poorly understood phenomenon thought to be related to increased posttransplant insulin production, immunosuppressive medications, and appetite changes. No study has investigated the effect of increased exocrine secretion posttransplant.

We hypothesized that exocrine function, measured by fecal elastase-1 (FE-1), was normal posttransplant and not correlated with weight gain. Our primary aim was to investigate changes in FE-1 levels with pancreas transplantation and to correlate this with weight gain. Establishing weight trends and identifying additional correlating factors were secondary aims.

Forty-two patients that underwent simultaneous pancreas and kidney or pancreas after kidney transplant at a single center between 2013 and 2021 were included. Fecal elastase was measured prospectively in each patient at a single time point, with >500 µg/g categorized as high. Weight and C-peptide values were obtained. All the patients were on steroid-free immunosuppression.

Nineteen patients (45%) had fecal elastase levels >500 µg/g, with a maximum of 3910 µg/g; 43% had levels greater than twice the upper limit of normal. The biggest increase in weight occurred between years 1 and 2, which continued to a median weight gain of 14% at 3 years. There was no correlation between weight gain and FE-1, pretransplant C-peptide levels, or duration of diabetes.

This study demonstrated supranormal fecal elastase levels and weight gain posttransplant; however, there was no correlation. Future study with serial FE-1 before and after transplant is needed to better assess its correlation with weight gain.