Impact of low-dose steroids on HbA1c levels and development of pre-diabetes and NODAT in non-diabetic renal transplant recipients on long-term follow-up.

BACKGROUND: This study aimed to evaluate the impact of 5 mg of prednisolone/day on HbA1c levels and its association with the development of pre-diabetes and new-onset diabetes mellitus (NODAT) in non-diabetic first renal transplant recipients on long-term follow-up.

METHODS: Four hundred patients were analysed on an average of 4.1 ± 3.0 years after successful transplantation: 96 (24%) were steroid-free and 304 (76%) treated with 5 mg of prednisolone/day combined with cyclosporine A (CsA) or tacrolimus (Tac) as part of their immunosuppressive protocol. Pre-diabetes and NODAT were defined based on the HbA1c levels according to the current ADA guidelines. The Mann-Whitney U test and the Chi-square test were used to determine intergroup differences. Multivariate logistic regression analyses (adjusted for steroid-free versus 5 mg of prednisolone per day, body mass index (BMI), number of HLA mismatches, eGFR according to the CKD-EPI formula, sex, negative vs. positive PRA titre, CMV and HCV positivity of the recipient, CsA vs. Tac immunosuppressive medication, dialysis vintage (years), age at the last follow-up and time from transplantation to the last follow-up) were performed to identify an independent effect of low-dose steroids on the evolution of pre-diabetes and NODAT.

RESULTS: A small but statistically significant difference in HbA1c levels was observed between the control and the steroid groups (5.56 ± 0.54 vs. 5.67 ± 0.0.45%, p = 0.045). The incidence rates of pre-diabetes and NODAT per 100 patients per year were 9.3 and 3.0, respectively. Regression analysis showed that low-dose steroids (p = 0.026, risk ratio (RR) 1.789, 95%; confidence interval (CI) 1.007-3.040) and age (p = 0.000, RR 1.037/year, 95% CI 1.018-1.057) were associated with pre-diabetes, whereas BMI (p = 0.000, RR 1.190, 95% CI 1.084-1.307), age (p = 0.000, RR 1.087/year, 95% CI 1.047-1.129) and Tac use (p = 0.010, RR 3.300, 95% CI 1.328-8.196) were associated with NODAT.

CONCLUSION: Using 5 mg of prednisolone/day was associated with increased HbA1c levels and an increased risk in developing pre-diabetes, but not NODAT, whereas BMI, age and the use of tacrolimus were associated with an increased risk in developing NODAT.