Patient survival after renal transplantation III: The effects of statins

Background: Kidney transplant recipients have high cardiovascular risk and an unfavorable cardiovascular risk profile, which frequently includes hyperlipidemia. Although the use of HMG-CoA reductase inhibitors (statins) is associated with improved survival in the general population, the effects of these drugs on the survival of kidney transplant recipients have not been established. Methods: In this study, we determined which factors were associated with the use of statins in a population of 1,574 adult, kidney allograft recipients, transplanted in one institution. A risk factor analysis of patient survival was done with a primary focus on the possible relationship between statin use and survival. Results: The percent of patients treated with statins increased progressively from 1982 to 1996. Statins were used significantly more often in whites (30%) than in blacks (20%, P = 0.001) and in older individuals. These differences in statin use were not due to differences in lipid levels among the patient groups. As expected, the group of patients treated with statins had significantly higher serum lipid levels than untreated patients. Patient survival was significantly better in patients treated with statins than in untreated patients. That relationship became apparent, however, only after controlling for three additional factors: recipient age, transplant year, and serum cholesterol levels. In a multivariable Cox survival model, patient survival was associated significantly with statin use (hazard ratio [HR] = 0.76; confidence interval [Cl], 0.6 to 0.96; P = 0.02), recipient age (HR = 1.05; Cl, 1.04 to 1.06; P < 0.0001), and transplant year (HR = 1.05; Cl, 1.01 to 1.08; P = 0.001). The serum cholesterol level was not associated significantly with patient survival in this model, but cholesterol significantly modified the relationship between statin use and patient survival. Conclusions: Renal transplant recipients treated with statins have a 24% better survival than patients who do not receive these drugs.