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. Longterm 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.