Diabetes Mellitus and Renal Transplantation

Diabetes mellitus after renal transplantation consists of both pre-existing diabetes and new-onset diabetes or NODM. Previously the term "post-transplant diabetes mellitus" or PTDM was used; however, this condition is distinct from pre-existing diabetes and may have its own underlying pathophysiology and clinical course. NODM is associated with markedly decreased dialysis-free patient survival and the same risk of developing all of the short- and long-term complications of diabetes. Risk factors include advanced age, African American or Hispanic ethnicity, a strong family history of diabetes, use of corticosteroids and tacrolimus, hepatitis C infection, and a history of glucose intolerance. Regular and fre- quent monitoring for the development of NODM, based on Canadian Diabetes Associa- tion (CDA) guidelines, is recommended for all renal transplant recipients and preventative strategies (eg, steroid minimization or avoidance) are becoming increasingly popular. An intensive multidisciplinary approach to patients with NODM is essential to ensure optimal allograft and patient outcomes. This issue of Endocrinology Rounds briefly reviews renal transplantation in the patient with diabetes and provides an extensive account of the unique entity of NODM. Renal transplantation in the patient with diabetes Over 170 million people in the world have diabetes (World Health Organization (WHO) 2003) and it is expected that the worldwide prevalence of diabetes will double between 1995 and 2010. Approximately 90%-95% of patients will have type 2 diabetes (American Diabetes Association (ADA) 2003). End-stage renal disease (ESRD) will even- tually develop in about 40% of patients with type 1 diabetes after 20 years. In those with type 2 diabetes, 5%-10% will progress to ESRD (ADA 2002), although this percentage is expected to increase with time. About 40% of ESRD is due to diabetes, with approximately half of these patients having type 2 diabetes. Renal transplantation is the therapeutic modality of choice for ESRD. It provides maximum replacement of renal function and offers the greatest potential for restoring a healthy and productive life. Transplantation also prolongs survival when compared to dia- lysis, even when compared to patients on the organ waiting list who are of presumably equivalent health. 1 Unfortunately, many patients with ESRD do not qualify for renal trans- plantation because they are too ill as a result of cardiovascular disease, malignancy, and other co-morbidities. Approximately 30% of renal transplant recipients (RTR) have co-existing diabetes. 2 However, patients with ESRD and diabetes present a special challenge when being consi- dered for transplantation since they have a higher mortality rate compared to non-diabetic patients due to multiple causes.