Preoperative Fasting Glucose Level a Predictor of New-Onset Diabetes after Transplantation

The 1-yr cumulative incidence of NODAT (New Onset Diabetes After Transplantation) was 27% in the 377 patients in this retrospective, observational study at the Mayo Clinic in Arizona. Before their kidney transplants, the patients did not have diabetes (fasting serum glucose <126 mg/dL, glycated hemoglobin [Hb A1c] <6.5%) and were not on therapy for diabetes.

The study defined NODAT as an Hb A1c >=6.5% or fasting serum glucose >=126 mg/dL or being prescribed a diet or medical therapy for diabetes between 1 month and 1 year post transplant.

"The bottom line is that even though the patient's pretransplant fasting glucose is in normal range, a fasting glucose of 110 mg/dL is not the same in terms of the risk it confers for NODAT as a blood glucose level of 90 mg/dL," Harini Chakkera, MD, MPH, Mayo Clinic, Phoenix, Arizona, said on May 1, 2010.

According to the study, a patient whose fasting glucose level is 90 mg/dL has 1.81 relative risk of developing NODAT post transplant compared with a patient whose fasting glucose level is >110 mg/dL, who has a 2.7 relative risk of developing NODAT, Dr. Chakkera said.

The overall mean age of the patients, all of whom received kidney transplants during 1999 to 2009, was 49 +- 15 years. Most (56%) of the patients were men, 70% were white, and 25% were obese, with a body mass index (BMI) >30 kg/m² before transplantation.

Post-transplant therapy included steroid maintenance immunosuppression for 44% of the patients at 1 month, 44% at 4 months, and 49% at 1 year. Both unadjusted and adjusted logistic regression models were used to determine risk conferred by patient characteristics on the development of future NODAT.

In the unadjusted analysis per 10-mg/dL increase in serum glucose, the odds ratio (OR) was 1.53 (95% confidence interval [CI], 1.023-1.89; P < .001). In the multivariate analysis per 10-mg/dL increase in serum glucose adjusted for BMI, recipient age, requirement of steroid as maintenance immunosuppression, tacrolimus level, and family history of diabetes, OR was 1.30 (95% CI, 1.07-1.58; P = .008).

The multivariate adjusted model also revealed that post-transplant steroid therapy and increasing age were statistically significant independent risk factors for NODAT.

NODAT has a significant adverse effect on healthcare costs, the patient's quality of life, and allograft and patient survival, and diminishes the gains of kidney transplantation, she added.

[Presentation title: Predictive Risk of Pre-Transplant Fasting Glucose on the Development of New Onset Diabetes After Kidney Transplantation. Abstract 689] presented at the May, 2010 American Transplant Congress (ATC).