Liver Enzymes and the Development of Posttransplantation Diabetes Mellitus in Renal Transplant Recipients

BACKGROUND: Posttransplantation diabetes mellitus (PTDM) is common in renal transplant recipients (RTR), increasing the risk of graft failure, cardiovascular disease, and mortality. Early detection of a high risk for PTDM is warranted. Because liver function and liver fat are involved, we investigated whether serum liver markers are associated with future PTDM in RTR. METHODS: Between 2001 and 2003, 606 RTR with a functioning allograft beyond the first year after transplantation were included of which 500 participants (56% men; age, 50 ± 12 years) were free of diabetes at baseline and had liver enzyme values (1 missing) available. Serum concentrations of alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), alkaline phosphatase were measured at baseline at 6.0 (6.2-11.5) years posttransplantation. PTDM cases were recorded until April 2012. RESULTS: During median follow-up for 9.6 years (interquartile range [IQR], 6.2-10.2) beyond baseline, 76 (15.2%) patients developed PTDM. Comparing the highest to the lower tertiles, higher liver enzyme activities were significantly related to incident PTDM for ALT (hazard ratio [HR], 2.22; IQR, 1.42-3.48), for GGT (HR, 2.93; IQR, 1.87-4.61), and for alkaline phosphatase (HR, 1.78; IQR, 1.13-2.80). The associations of ALT and GGT with development of PTDM were independent of potential confounders and risk factors, including age, sex, renal function, medication use, lifestyle factors, adiposity, presence of the metabolic syndrome, fasting glucose, HbA1c, proinsulin, and cytomegalovirus status. CONCLUSIONS: Markers for liver function and liver fat in the subclinical range are potential markers for future PTDM, independent of other known risk factors. This may allow for early detection and management of PTDM development.