The combined effect of pre-transplant triglyceride levels and the type of calcineurin inhibitor in predicting the risk of new onset diabetes after renal transplantation

Background. Insulin resistance precedes overt diabetes in the general population and hypertriglyceridemia is a reliable marker of the disorder. Thus, patients in the waiting list with hypertriglyceridemia may be at risk for new-onset diabetes after transplantation ( NODAT). Objectives. We investigate whether pre-transplant triglyceride ( TG) levels are a risk factor for NODAT and whether they exert a combined effect with the type of calcineurin inhibitor ( CNI). Methods. We analysed 314 consecutive non-diabetic recipients [ 215 cyclosporine A ( CsA); 99 tacrolimus ( Tacro)] transplanted between 1999 and 2003 with a mean followup of 34 months. Outcome was NODAT defined by ADA criteria. Results. NODAT developed in 81 recipients ( 25.8%). Multivariate analysis which included a propensity score for factors determining CNI allocation showed that age ( OR: 1.06; 95% CI: 1.03 - 1.09), pre-transplant BMI ( OR: 1.1; 95% CI: 1.02 - 1.17), TG levels ( OR: 1.3 per 50 mg/ dl increment, 95% CI: 1.07 - 1.6) and treated acute rejection ( OR: 4.8, 95% CI: 3 - 11), but not the type of CNI, were independent risk factors for NODAT. A significant interaction between pre- transplant TG and type of CNI was observed. Using CsA as the reference, the combination of Tacro plus pretransplant hypertriglyceridemia (>= 200 mg/ dl) showed an OR of 3.26 ( 1.4 - 7.8) to develop NODAT, contrasting with an OR of 0.75 ( 0.34 - 1.6) in Tacro recipients with pretransplant TG levels <200 mg/ dl. Conclusion. Pre-transplant hypertriglyceridemia was a risk factor for NODAT only in recipients treated with Tacro; it highlights the importance of pre- transplant insulin resistance in the pathogenesis of NODAT.