Prevalence and prognosis of mild anemia in non-dialysis chronic kidney disease: a prospective cohort study in outpatient renal clinics.
OBJECTIVE
we evaluated prevalence and prognosis of mild anemia, defined as Hb (g/dl) 11-13.5 in males and 11-12 in females, in a prospective cohort of stage 3-5 chronic kidney disease (CKD) patients.


METHODS
we enrolled 668 consecutive patients in 25 renal clinics during 2003. Patients with frank anemia (Hb <11 or erythropoiesis-stimulating agents) at enrolment were excluded. Mild anemia was evaluated at two visits planned with an interval of 18 ± 6 months to identify four categories: no anemia at both visits, mild anemia at visit 1 resolving at visit 2 (RES), mild anemia persisting at both visits (PER), and progression from no anemia or mild anemia at visit 1 to mild or frank anemia at visit 2 (PRO).


RESULTS
mild anemia was present in 41.3% at visit 1 and 34.1% at visit 2. We identified PER in 22% patients, RES in 10%, and PRO in 26%. In the subsequent 40 months, 125 patients developed end-stage renal disease (ESRD) and 94 died. At competing risk model, PER predicted ESRD (hazard ratio, HR, 1.82, 95% confidence interval, CI, 1.01-3.29) while PRO predicted both ESRD (HR 1.81, 95% CI 1.02-3.23) and death (HR 1.87, 95% CI 1.04-3.37).


CONCLUSIONS
in non-dialysis chronic kidney disease, mild anemia is prevalent and it is a marker of risk excess when persistent or progressive over time.
De Nicola
Luca
L
Nephrology Division and Chair of Biostatistics, Second University of Naples, Naples, Italy. luca.denicola@unima2.it
Minutolo
Roberto
R
Chiodini
Paolo
P
Zamboli
Pasquale
P
Cianciaruso
Bruno
B
Nappi
Felice
F
Signoriello
Simona
S
Conte
Giuseppe
G
Zoccali
Carmine
C
SIN-TABLE CDK Study Group
D000368:Aged; D000369:Aged, 80 and over; D000554:Ambulatory Care Facilities; D000740:Anemia / Q000453:epidemiology* / Q000209:etiology; D018450:Disease Progression; D005260:Female; D005919:Glomerular Filtration Rate; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000401:mortality; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015995:Prevalence; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000150:complications*; D016019:Survival Analysis
D006454:Hemoglobins