Background Limited data are available regarding a post-transplant improvement of β-cell function and insulin sensitivity of functioning pancreas transplants in patients with type 2 diabetes mellitus (T2DM) compared with type 1 diabetes mellitus (T1DM).
Methods To compare the metabolic effects of pancreas transplantation in terms of β-cell function and insulin sensitivity, comparison of metabolic variables was performed using oral glucose tolerance test between T1DM and T2DM patients pre-transplant and one month post-transplant.
Results Among 65 consecutive patients who underwent pancreas transplantation at our center between April, 2015 and December, 2016, a total of 29 patients (22 T1DM and 7 T2DM) were performed pre- and post-transplant oral glucose tolerance test. Insulinogenic index (0.693 ± 2.261 vs 0.035 ± 0.082, p = 0.186) and disposition index (2.363 ± 7.571 vs 0.364 ± 0.996, p = 0.237) in T1DM recipients were likely to increase post-transplant rather than pre-transplant but failed to get statistical significance. Insulin sensitivity determined by Matsuda’s index (3.825 ± 2.140 vs 8.686 ± 8.046, p = 0.015) was significantly decreased one month post-transplant rather than pre-transplant. Meanwhile, insulinogenic index (1.577 ± 2.533 vs 0.008 ± 0.118, p = 0.145) and disposition index (3.962 ± 6.441 vs 0.009 ± 0.262, p = 0.155) in T2DM recipients were also likely to increase post-transplant rather than pre-transplant. There was no significant difference in Matsuda’s index (3.700 ± 2.597 vs 5.034 ± 4.819, p = 0.604) between pre- and post-transplant. Post-transplant levels of serum glucagon significantly decreased compared with the levels pre-transplant when oral glucose tolerance test was performed.
Conclusions Neither in T1DM nor T2DM recipient, we could verify the improvement of insulin sensitivity one month post-transplant whereas β-cell function tended to improve in both. It is postulated that insulin sensitivity in early post-transplant period is influenced by high dose calcineurin inhibitor. Long-term follow up analysis is necessary to evaluate the beneficial effect of pancreas transplantation in terms of insulin sensitivity, especially in T2DM.