Hypertension in kidney transplant recipients. Effect on long-term renal allograft survival

To examine the effects of hypertension on renal graft function, we studied the clinical course of 144 kidney transplant recipients who had functioning grafts for three to 13 years. The patients were divided into three groups: normotensive (n = 32), controlled hypertensive (n = 49) and uncontrolled hypertensive group (n = 63). In addition to the difference in their blood pressure status, the three groups had significantly different levels of serum creatinine at entry to the study (mean +/- SE in mg/dL: 1.41 +/- 0.02, 8.89 +/- 0.02 and 2.30 +/- 0.03, respectively, P = .0002). Cumulative graft survival (CGS) at ten years for normotensive patients was 81%, whereas it was 58% for controlled hypertensive patients and 50% for uncontrolled hypertensive patients. The difference of CGS between normotensive and hypertensive patients was significant (P = .01), whereas the difference between the two hypertensive groups, controlled v. uncontrolled, was not. If serum creatinine levels at entry to the study were adjusted and the CGS of hypertensive patients was compared to normotensive patients with comparable levels of serum creatinine, the differences in CGS between the two groups were no longer significant. Regression analyses for potential prognostic factors revealed that serum creatinine levels were of more primary importance as a prognostic variable than blood pressure status. We conclude that hypertension is an important risk factor for renal graft survival, but control of hypertension alone does not appear to improve it. Graft survival appears to be influenced more by the severity of graft dysfunction at entry to the study irrespective of blood pressure control.