A REDUCED INCIDENCE OF CORTICOSTEROID-RELATED OSTEONECROSIS IN DIABETICS

Abstract

Introduction: Osteonecrosis (ON) is a disabling disease, which often affects young adults after corticosteroid immunosuppression for organ transplantation. Reducing risk factors remains the only preventive measure for this condition. Our goal was to determine if diabetes has any influence in developing ON after kidney transplantation.

Materials and Methods: We identified 2881 renal transplantation patients with the following inclusion criteria: age > 16 years, no history of corticosteroid exposure. There were 1762 (61%) diabetics and 1119 (39%) non-diabetics. Mean age was 43 years (range, 16 to 77) and mean follow-up was 128 months (range, 36 to 242). Osteonecrosis free survivorship was defined as time from transplant to diagnosis of ON.

Results: Kaplan-Meier life table analysis at 5 years revealed that the incidence of ON was 4% for diabetics vs. 9% for non-diabetics (ON- free survivorship 96%, [95% confidence interval 0.952 to 0.970] vs. 91% [95% C.I. 0.896 to 0.929], respectively [p < 0.0001]). At 10 years, the ON incidence was 5% for diabetics vs. 10% for non-diabetics representing a 50% reduction.

Diabetes was the strongest independently predictive factor for ON-free survival (relative risk 0.47, p< 0.0001), while other factors were also independently significant but had a weaker relationship; (rejection episodes [RR 1.17, p=0.009], year of transplantation [RR 0.96, p=0.01]).

Discussion: Although the most common reason for renal transplantation, in adults, is diabetic nephropathy (61%), only a small fraction actually developed ON as compared to the non-diabetic population. The reason for this is unknown but might be related to lipid metabolism, high glucose levels, or neovascularization analogous to diabetic retinopathy.

Presence of diabetes is associated with a dramatic risk reduction in developing ON. The magnitude of the risk reduction was greatest for diabetes as compared to all other risk factors analyzed.