Hyperglycemia in the Posttransplant Period: NODAT vs Posttransplant Diabetes Mellitus

OBJECTIVE: To characterize the types of hyperglycemia that occur up to 1 year following liver transplant and to clarify the nomenclature for posttransplant hyperglycemia. DESIGN: We analyzed 1-year glycemic follow-up data in 164 patients who underwent liver transplant and who had been enrolled in a randomized controlled trial comparing moderate to intensive insulin therapy to determine if patients had preexisting known diabetes, transient hyperglycemia, persistent hyperglycemia, or new-onset diabetes after transplantation (NODAT). RESULTS: Of 119 patients with posttransplant hyperglycemia following hospital discharge, 49 had preexisting diabetes, 5 had insufficient data for analysis, 48 had transient hyperglycemia (16 resolved within 30 days and 32 resolved between 30 days and 1 year), 13 remained persistently hyperglycemic out to 1 year and most likely had preexisting diabetes that had not been diagnosed or insulin resistance/insulinopenia prior to transplant, and 4 had NODAT (i.e., patients with transient hyperglycemia after transplant that resolved but then later truly developed sustained hyperglycemia, meeting criteria for diabetes). CONCLUSIONS: Distinct categories of patients with hyperglycemia following organ transplant include known preexisting diabetes, persistent hyperglycemia (most likely unknown preexisting diabetes or insulin resistance/insulinopenia), transient hyperglycemia, and NODAT. Those with preexisting diabetes for many years prior to transplant may well have very different long-term outcomes compared with those with true NODAT. Therefore, it would be prudent to classify patients more carefully. Long-term outcome studies are needed to determine if patients with true NODAT have the same poor prognosis as patients with preexisting diabetes (diagnosed and undiagnosed) undergoing transplant.