Incidence and risk factors of glucose metabolism disorders in kidney transplant recipients: role of systematic screening by oral glucose tolerance test.

BACKGROUND: New-onset diabetes after transplantation (NODAT) increases infectious and cardiovascular complications and reduces patient and graft survival. We assessed the incidence and the risk factors for glucose metabolism abnormalities before and after kidney transplantation using an oral glucose tolerance test (OGTT). The purpose of the study was to better identify patients at risk for NODAT to adapt their immunosuppressive treatment and their management after transplantation.
METHODS: OGTT was performed before transplantation in 243 patients placed on the kidney waiting list between January 1, 2005, and December 31, 2008. Of these 243 patients, 120 received a kidney transplant and also had an OGTT after transplantation.
RESULTS: Impaired glucose tolerance (IGT) was identified in 22 of 120 patients (18%) before transplantation. After transplantation, diabetes developed in 31 patients and 16 patients had IGT. According to univariate analyses, risk factors for NODAT were age more than 50 years, body mass index more than 25 kg/m, pretransplant IGT, autosomal dominant polycystic kidney disease, and acute rejection. According to multivariate analyses, pretransplant IGT (relative risk=2.4), autosomal dominant polycystic kidney disease (relative risk=3), and acute rejection (RR, 2.8) remained significantly associated with NODAT. Patients were stratified by age, primary kidney disease, and pretransplant OGTT. The risk of developing NODAT increased 2.4-, 5-, and 14-fold, depending on the number of risk factors.
CONCLUSION: Pretransplant OGTT, together with age and nephropathy, is a helpful tool for identifying patients at risk for NODAT. For patients with two or three of these risk factors, the adjustment of immunosuppression may be recommended.