New-onset diabetes mellitus and the analysis of dipeptidyl-peptidase-4 after liver transplantation.

BACKGROUND

New-onset diabetes mellitus after transplantation (NODAT) is a common complication after orthotopic liver transplantation (OLT). The diabetogenic effect of hepatitis C virus (HCV) infection is well known. The aim of this study was to analyze the glucose homeostasis before and after OLT. The oral glucose tolerance test (OGTT) was carried out, and dipeptidyl-peptidase-4 (DPP-4) activity was measured.

METHODS

The study period was from 2012 to 2014. We enrolled 49 non-diabetic patients from the waiting list (group A) and 21 patients after OLT (group B). Seven patients were monitored continuously both before and after OLT. According to our preoperative OGTT results, 13 patients in group A had newly diagnosed diabetes mellitus (group A/DM) and 11 had impaired glucose tolerance (group A/IGT). In 25 cases, normal glucose tolerance was diagnosed (group A/NGT). The calculated homeostasis model assessment insulin resistance (HOMA2-IR) values were both in group A/DM and-IGT higher compared with group A/NGT (2.42 ± 0.81 vs 2 ± 0.98 vs 1.28 ± 0.67; P = .001). In the case of HCV infection (n = 14; 29%) DM and IGT were more frequent.

RESULTS

Six patients in group B had NODAT. In 9 cases, IGT and in 6 cases NGT was detected. In the case of HCV infection (n = 9; 43%), DPP-4 levels were higher compared with that in patients with all other indications for OLT (15.5 ± 5.2 vs 8.7 ± 3.5; P = .008). We evaluated the same individuals before and after OLT (n = 7), and a decrease in β-cell function was noted.

CONCLUSIONS

Preoperative OGTT is an important and easy investigation to rule out glucose imbalance before OLT. The HOMA2 calculation can also be useful both in preoperative and postoperative risk assessment. In our results, DPP-4 activity is not specific for the type of glucose homeostasis imbalance, but, in HCV infection, it is higher. DPP-4 inhibitors can be effective in the therapy of NODAT, especially in HCV-infected patients.