Cardiovascular consequences of new-onset hyperglycemia after kidney transplantation

Abstract

Background: New-onset diabetes after transplantation (NODAT) is associated with high cardiovascular (CV) risk and reduced patient survival. It is unclear whether this risk is newly acquired or represents preexisting CV disease in patients with this complication.

Methods: Included are 1146 adults, recipients of first kidney transplants from 1984 to 2008 treated with modern immunosuppressants.

Results: One year after transplantation, 29.8% of patients experienced impaired fasting glycemia and 13.4% NODAT. The risk of NODAT related to recipient variables include the following: older age, male gender, higher body mass index, higher pretransplantation glucose and triglyceride levels, and lower high-density lipoprotein level. Increasing fasting glucose levels at 1, 4, or 12 months after transplantation, independent of other factors, related to reduced patient survival (12 months hazard ratio [HR]=1.146 [1.132-1.161], P<0.0001 for 10mg/dL increase in glucose), and this was primarily because of an increase in CV deaths. Hyperglycemia related to all major CV events (MCVE), cardiac (HR=1.113 [1.094-1.132], P<0.0001), vascular (HR=1.168 [1.140-1.197], P<0.0001), and strokes (HR=1.156 [1.123-1.191], P=0.003). These relations were statistically independent of other risk factors. The increased risk of MCVE was noted particularly in patients without MCVE before transplantation (HR=1.145 [1.126-1.165], P<0.0001). Furthermore, among patients with after transplantation MCVE (n=123, 11%), hyperglycemia increases the risk of death (NODAT: HR=2.410 [1.125-5.162], P=0.024).

Conclusions: After transplantation hyperglycemia is a strong independent risk factor for MCVE and death, mainly from CV causes. This risk is independent of the presence of CV disease identified before transplantation.

Conflict of interest statement

The authors declare no conflicts of interest.

Figures

FIGURE 1

Kaplan-Meier plots showing cumulative mortality (A) and cumulative incidence of posttransplantation major cardiovascular events (B) in patients classified according to fasting plasma glucose (FPG) levels 1 year after transplantation: Normal FPG (—), impaired fasting glycemia (IFG) (– – –), and new-onset diabetes after transplantation (NODAT) (+–+–+). Log-rank test: (A) P=0.0001, (B) P<0.0001. A, shows the numbers of patients in each group at different time points. These numbers apply to both (A) and (B).

FIGURE 2

A, Cumulative incidence of posttransplantation major cardiovascular events (MCVE) in patients with no MCVE before transplantation (Tx) and no post-Tx hyperglycemia (—), patients with no MCVE before Tx but with post-Tx hyperglycemia (+–+–+), and patients with pre-Tx MCVE whether or not they showed post-Tx hyperglycemia (– – –) (Log-rank test: P<0.0001). B, Cumulative mortality in the same three groups of patients (Log-rank test: P<0.0001). B, indicates the numbers of patients in each group at different time points. These numbers apply to both (A) and (B). FPG, fasting plasma glucose.