Prospective analysis of the value of 24-hour ambulatory blood pressure on renal function after kidney transplantation.
BACKGROUND
No prospective study has been performed to determine the prognostic value of 24-hr ambulatory blood pressure (24-hr ABP) versus casual blood pressure (CBP) in patients after kidney transplantation. We have addressed this issue by analyzing renal graft function in patients for the first 5 years after transplantation.


METHODS
The 24-hr ABP (SpaceLabs 90207) was monitored 6 and 18 months after transplantation in 46 renal transplant recipients without any acute episodes of rejection. Combined study endpoints were death of patients, need for dialysis, second transplantation, and doubling of serum creatinine.


RESULTS
Six months after transplantation systolic and diastolic 24-hr ABP correlated with serum creatinine (r=0.41, P=0.005 and r=0.37, P<0.01, respectively) although CBP did not. Divided into tertiles according to average 24-hr ABP (lower tertile: < or =91 mmHg; middle tertile: 92-97 mmHg; upper tertile: > or =98 mmHg) serum creatinine significantly differed between the three groups (1.26 +/- 0.38 vs. 1.32 +/- 0.25 vs. 1.65 +/- 0.39 mg/dl, respectively; analysis of variance, P< 0.01). Confounding factors of renal function such as age, body weight, cold and warm ischemic time, cytomegaly virus status, methylprednisone and cyclosporine dosages, cyclosporine concentrations, as well as concomitant antihypertensive medication did not differ among the three groups. In the long-term follow-up (5 years), combined endpoints were reached in 3 of 15 of the lower tertile group, in 3 of 15 of the median tertile group, and in 8 of 16 of the upper tertile group (log-rank test, P<0.01). No relation to long-term out come was found when patients were stratified according to their CBP.


CONCLUSIONS
In our small but homogenous study cohort 24-hr ABP was more closely related to renal function in patients after transplantation than CBP suggesting that 24-hr ABP is superior for evaluation of hypertension-related renal graft dysfunction.
Jacobi
J
J
Department of Medicine/Nephrology, University of Erlangen-Nürnberg, Germany.
Rockstroh
J
J
John
S
S
Schreiber
M
M
Schlaich
M P
MP
Neumayer
H H
HH
Schmieder
R E
RE
D000328:Adult; D018660:Blood Pressure Monitoring, Ambulatory; D003404:Creatinine / Q000097:blood; D006085:Graft Survival; D006801:Humans; D007668:Kidney / Q000502:physiology*; D016030:Kidney Transplantation / Q000276:immunology / Q000502:physiology*; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D016896:Treatment Outcome
D003404:Creatinine