Posttransplantationsdiabetes mellitus bei Patienten nach Nierentransplantation: Inzidenz und Risikofaktoren

Abstract

Background: Transplantation (NTX) associated ischemia-reperfusion-mechanisms and the predisposition for insulin resistance are discussed as causes of a posttransplantation diabetes mellitus (PTDM). Furthermore, immunosuppressants can have a damaging effect on insulin secretion. Methods: 55 metabolically healthy patients with an endstage renal disease (age 52 ± 14 years, body mass index 27 ± 5 kg / m2, blood pressure 137 ± 15/82 ± 11 mmHg) were included in a prospectively cohort study. These patients were transplanted between 2009 and 2011 (82 % of the NTX patients). Baseline examination was performed before NTX. Within the 2nd week as well as 6 and 12 months after transplantation an oral glucose tolerance test (oGGT), 3 and 9 months after NTX a glucagon test took place. In these connections the determination of plasma glucose, C-peptide and insulin was performed. Study endpoints were: graft failure, impaired glucose tolerance (iGT), PTDM, patient's death. Results: Over a follow-up-period of 1 year post NTX iGT / PTDM occurred in 31 % and graft failure in 13 %. In comparison with the healthy control group patients with iGT / PTDM were older (59 ± 8 vs. 48 ± 14ys, p = 0.001), overweight (BMI 29 ± 4 vs. 26 ± 5 kg / m2, p = 0.038), showed an indication of an insulin resistance before NTX (HOMA 4.0 ± 2.9 vs. 2.4 ± 1.4, p = 0.013; C-peptide 10.1 ± 5.2 vs. 7.1 ± 3.6 ng / ml, p = 0.014; insulin 14.6 ± 9.4 vs. 10.6 ± 5.5mU / l, p = 0.045) and higher HbA1c levels (5.6 ± 0.5 vs. 5.4 ± 0.4 %, p = 0.032). Age (p = 0.001), fasting plasma glucose (p = 0.042), the glucose levels of oGTT immediately after transplantation were shown as prognostically relevant (fasting glucose: p = 0.027; 1 h: p = 0.014; 2 h: p = 0.002). An isolated defective secretion as a result of a toxic damage to the β-cells by immunosuppressants couldn't be shown in any of the patients with iGT / PTDM. 4 % of the patients died in the first year after NTX. Conclusion: In 31 % a disorder of glucose metabolism was found as a frequent complication after NTX. The HOMA index was found to be a meaningful marker for an existing insulin resistance. The fasting glucose before and an oGTT in the first weeks after NTX showed itself as clinically valid laboratory parameters for a risk assessment.