Silent brain infarction and rapid decline of kidney function in patients with CKD: a prospective cohort study.
BACKGROUND
Several reports have found that chronic kidney disease (CKD) is an independent risk factor for stroke. However, little is known about whether cerebrovascular disease conversely predicts the outcome of kidney function. In view of the similarities between vascular beds of the kidney and brain, we hypothesized that silent brain infarction (SBI) could reflect the degree of injury in renal small vessels and predict the risk of progression of kidney disease.


METHODS
Prospective cohort study.


METHODS
142 patients with CKD (stages 3-5) admitted to our clinic for education about CKD from January 2006 to July 2007 were recruited and followed up for 2 years.


METHODS
SBI.


RESULTS
Composite primary outcomes: doubling of serum creatinine level, development of end-stage renal disease defined as dialysis or transplant, and death from cardiovascular causes. Secondary outcome: rate of decrease in estimated glomerular filtration rate.


METHODS
Brain magnetic resonance imaging was performed to determine the presence or absence of SBI.


RESULTS
At baseline, 87 patients had SBI. During follow-up, 43 patients (30.3%) developed the following primary outcomes: doubling of serum creatinine level (8 patients), dialysis therapy (32 patients), and death from cardiovascular causes (3 patients). In crude analysis, the presence of SBI predicted time to primary outcomes (P=0.01). A multivariate Cox model confirmed the presence of SBI to be an independent predictor of study outcomes (HR, 2.16; 95% CI, 1.01-4.64; P=0.04). Estimated glomerular filtration rate decreased more in patients with SBI than in those without SBI (-0.11/y vs -0.06/y relative to baseline value; P=0.005).


CONCLUSIONS
Study size was small.


CONCLUSIONS
We showed that SBI was an important independent prognostic factor for the progression of kidney disease in patients with CKD. Our findings suggest that patients with SBI should be considered a high-risk population for decreased kidney function.
Kobayashi
Mayumi
M
Division of Nephrology and Hypertension, Yokohama City University Medical Center, Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine and School of Medicine, Yokohama, Japan.
Hirawa
Nobuhito
N
Morita
Satoshi
S
Yatsu
Keisuke
K
Kobayashi
Yusuke
Y
Yamamoto
Yuichiro
Y
Saka
Sanae
S
Toya
Yoshiyuki
Y
Yasuda
Gen
G
Umemura
Satoshi
S
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020520:Brain Infarction / Q000150:complications*; D002908:Chronic Disease; D018450:Disease Progression; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000209:etiology* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D013997:Time Factors