Renal resistance index in renal allograft recipients: a role for ADMA.
BACKGROUND
Renal resistance index, a predictor of kidney allograft function and patient survival, seems to depend on renal and peripheral vascular compliance and resistance. Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthase and therefore influences vascular resistance.


METHODS
We investigated the relationship between renal resistance index, ADMA, and risk factors for cardiovascular diseases and kidney function in a cross-sectional study.


METHODS
200 stable renal allograft recipients (133 men and 67 women with a mean age of 52.8 years).


METHODS
Serum ADMA concentration, pulse pressure, estimated glomerular filtration rate and recipient age.


RESULTS
Renal resistance index.


METHODS
Renal resistance index measured by color-coded duplex ultrasound, serum ADMA concentration measured by liquid chromatography-tandem mass spectrometry, estimated glomerular filtration rate (Nankivell equation), arterial stiffness measured by digital volume pulse, Framingham and other cardiovascular risk factors, and evaluation of concomitant antihypertensive and immunosuppressive medication.


RESULTS
Mean serum ADMA concentration was 0.72 +/- 0.21 (+/-SD) micromol/L and mean renal resistance index was 0.71 +/- 0.07. Multiple stepwise regression analysis showed that recipient age (P < 0.001), pulse pressure (P < 0.001), diabetes (P < 0.01) and ADMA concentration (P < 0.01) were independently associated with resistance index. ADMA concentrations were correlated with estimated glomerular filtration rate (P < 0.01).


CONCLUSIONS
The cross-sectional nature of this study precludes cause-effect conclusions.


CONCLUSIONS
In addition to established cardiovascular risk factors, ADMA appears to be a relevant determinant of renal resistance index and allograft function and deserves consideration in prospective outcome trials in renal transplantation.
Bergmann
Ivo P
IP
Department of Nephrology and Hypertension, University of Bern, Inselspital, Bern, Switzerland.
Böger
Rainer H
RH
Marti
Elizabeth
E
Frey
Felix J
FJ
Schwedhelm
Edzard
E
Eisenberger
Ute
U
D000328:Adult; D000368:Aged; D001120:Arginine / Q000031:analogs & derivatives* / Q000097:blood / Q000502:physiology; D005260:Female; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D012077:Renal Artery / Q000502:physiology*; D014655:Vascular Resistance; D055815:Young Adult
C018524:N,N-dimethylarginine; D001120:Arginine