title: Hemoglobin variability does not predict mortality in European hemodialysis patients.
abstract: Patients with CKD exhibit significant within-patient hemoglobin (Hb) level variability, especially with the use of erythropoiesis stimulating agents (ESAs) and iron. Analyses of dialysis cohorts in the United States produced conflicting results regarding the association of Hb variability with patient outcomes. Here, we determined Hb variability in 5037 European hemodialysis (HD) patients treated over 2 years to identify predictors of high variability and to evaluate its association with all-cause and cardiovascular disease (CVD) mortality. We assessed Hb variability with various methods using SD, residual SD, time-in-target (11.0 to 12.5 g/dl), fluctuation across thresholds, and area under the curve (AUC). Hb variability was significantly greater among incident patients than prevalent patients. Compared with previously described cohorts in the United States, residual SD was similar but fluctuations above target were less frequent. Using logistic regression, age, body mass index, CVD history, dialysis vintage, serum albumin, Hb, angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) use, ESA use, dialysis access type, dialysis access change, and hospitalizations were significant predictors of high variability. Multivariable adjusted Cox regression showed that SD, residual SD, time-in-target, and AUC did not predict all-cause or CVD mortality during a median follow-up of 12.4 months (IQR: 7.7 to 17.4). However, patients with consistently low levels of Hb (<11 g/dl) and those who fluctuated between the target range and <11 g/dl had increased risks for death (RR 2.34; 95% CI: 1.24 to 4.41 and RR 1.74; 95% CI: 1.00 to 3.04, respectively). In conclusion, although Hb variability is common in European HD patients, it does not independently predict mortality.
authors.affiliation: Department of Nephrology and Hypertension, University of Erlangen-Nuremberg, Erlangen, Germany. Kai-Uwe.Eckardt@uk-erlangen.de
authors.forename: Kai-Uwe
authors.initials: KU
authors.lastname: Eckardt
authors.forename: Joseph
authors.initials: J
authors.lastname: Kim
authors.forename: Florian
authors.initials: F
authors.lastname: Kronenberg
authors.forename: Pedro
authors.initials: P
authors.lastname: Aljama
authors.forename: Stefan D
authors.initials: SD
authors.lastname: Anker
authors.forename: Bernard
authors.initials: B
authors.lastname: Canaud
authors.forename: Bart
authors.initials: B
authors.lastname: Molemans
authors.forename: Peter
authors.initials: P
authors.lastname: Stenvinkel
authors.forename: Guntram
authors.initials: G
authors.lastname: Schernthaner
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Ireland
authors.forename: Bruno
authors.initials: B
authors.lastname: Fouqueray
authors.forename: Iain C
authors.initials: IC
authors.lastname: Macdougall
mesh_terms: D000368:Aged; D005060:Europe / Q000453:epidemiology; D005260:Female; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000378:metabolism* / Q000401:mortality / Q000628:therapy; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis
chemical_list: D006454:Hemoglobins
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