Influence of atherosclerosis on the relationship between anaemia and mortality risk in haemodialysis patients.
BACKGROUND
Full, as compared with partial, correction of anaemia did not reduce the mortality risk in patients with chronic kidney disease (CKD), although the underlying mechanisms are unknown. Since CKD is a high-risk population for cardiovascular disease (CVD), we tested a hypothesis that the presence of atherosclerosis affects the relationship between anaemia and mortality risk.


METHODS
We performed a single-centre 10-year follow-up study with an observational cohort of 505 haemodialysis patients to analyse the relationship between haematocrit and all-cause mortality. Baseline haematocrit levels did not differ between the 153 patients with CVD and the 352 patients without CVD.


RESULTS
During the follow-up, 268 patients died. Both Kaplan-Meier and univariate Cox analyses showed that higher haematocrit levels were a significant predictor of lower risk of death in the CVD (-) group, whereas haematocrit did not predict death in the CVD (+) group. In multivariate Cox analyses, the inverse relationship between haematocrit and mortality in the CVD (-) group remained significant and independent of 14 covariates including the use of erythropoietin. In contrast, using the same Cox models, the CVD (+) group did not show such a beneficial effect of higher haematocrit. Similar observations were made when the subjects were divided based on carotid artery intima-media thickness instead of the presence of CVD.


CONCLUSIONS
These results support the hypothesis that the presence of atherosclerosis alters the relationship between anaemia and mortality risk in haemodialysis patients.
Maekawa
Kiyoshi
K
Kidney Center, Shirasagi Hospital, Osaka, Japan.
Shoji
Tetsuo
T
Emoto
Masanori
M
Okuno
Senji
S
Yamakawa
Tomoyuki
T
Ishimura
Eiji
E
Inaba
Masaaki
M
Nishizawa
Yoshiki
Y
D000368:Aged; D000740:Anemia / Q000503:physiopathology*; D050197:Atherosclerosis / Q000503:physiopathology*; D002339:Carotid Arteries / Q000000981:diagnostic imaging; D002908:Chronic Disease; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006400:Hematocrit; D006801:Humans; D053208:Kaplan-Meier Estimate; D007674:Kidney Diseases / Q000401:mortality* / Q000503:physiopathology / Q000628:therapy*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D006435:Renal Dialysis; D012307:Risk Factors; D016896:Treatment Outcome; D014463:Ultrasonography