Uric acid and long-term outcomes in CKD.
BACKGROUND
Hyperuricemia is prevalent in patients with chronic kidney disease (CKD); however, data are limited about the relationship of uric acid levels with long-term outcomes in this patient population.


METHODS
Cohort study.


METHODS
The Modification of Diet in Renal Disease (MDRD) Study was a randomized controlled trial (N = 840) conducted from 1989 to 1993 to examine the effects of strict blood pressure control and dietary protein restriction on progression of stages 3 to 4 CKD. This analysis included 838 patients.


METHODS
Uric acid level.


METHODS
The study evaluated the association of baseline uric acid levels with all-cause mortality, cardiovascular disease (CVD) mortality, and kidney failure.


RESULTS
Mean age was 52 +/- 12 (SD) years, glomerular filtration rate was 33 +/- 12 mL/min/1.73 m(2), and uric acid level was 7.63 +/- 1.66 mg/dL. During a median follow-up of 10 years, 208 (25%) participants died of any cause, 127 (15%) died of CVD, and 553 (66%) reached kidney failure. In multivariate models, the highest tertile of uric acid was associated with increased risk of all-cause mortality (hazard ratio [HR], 1.57; 95% confidence interval [CI], 1.07 to 2.32), a trend toward CVD mortality (HR, 1.47; 95% CI, 0.90 to 2.39), and no association with kidney failure (HR, 1.20; 95% CI, 0.95 to 1.51) compared with the lowest tertile. In continuous analyses, a 1-mg/dL greater uric acid level was associated with 17% increased risk of all-cause mortality (HR, 1.17; 95% CI, 1.05 to 1.30) and 16% increased risk of CVD mortality (HR, 1.16; 95% CI, 1.01 to 1.33), but was not associated with kidney failure (HR, 1.02; 95% CI, 0.97 to 1.07).


CONCLUSIONS
Primary analyses were based on a single measurement of uric acid. Results are generalizable primarily to relatively young white patients with predominantly nondiabetic CKD.


CONCLUSIONS
In patients with stages 3 to 4 CKD, hyperuricemia appears to be an independent risk factor for all-cause and CVD mortality, but not kidney failure.
Madero
Magdalena
M
Department of Medicine, Division of Nephrology, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico.
Sarnak
Mark J
MJ
Wang
Xuelei
X
Greene
Tom
T
Beck
Gerald J
GJ
Kusek
John W
JW
Collins
Allan J
AJ
Levey
Andrew S
AS
Menon
Vandana
V
D002318:Cardiovascular Diseases / Q000097:blood / Q000150:complications / Q000401:mortality; D002423:Cause of Death / Q000639:trends; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D033461:Hyperuricemia / Q000097:blood / Q000453:epidemiology* / Q000209:etiology; D007668:Kidney / Q000503:physiopathology; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000150:complications / Q000401:mortality; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D014527:Uric Acid / Q000097:blood*
D014527:Uric Acid