Anemia–Why It Is Important
Transcript of Anemia–Why It Is Important
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Anemia is prevalent in the aging population. Several
observational population-based studies have demonstrat-
ed decreasing hemoglobin (Hb) levels with advancing
age1 as well as high rates of anemia in community-
dwelling elderly individuals.2 Unfortunately, even as it is
common, the level of its recognition as an important clin-
ical entity in certain individuals may be relatively low.
Anemia is rarely an admitting diagnosis3 and cases classi-
fied according to standard definitions may not be treated
at all.4 However, emerging data support more vigilance
and possibly higher rates of treatment for anemia in
elderly individuals. This article will discuss the rationale
for i n c reased awareness of anemia, the consequences of a n e-
mia, and potential etiologies that increase risk of adverse events.
A summary of potential signs and symptoms of anemia
(Figure 1) reveals that many of the body’s systems may be
adversely affected.5 Central nervous system signs of ane-
mia include fatigue, vertigo, depression, and low cogni-
tive function. Gastrointestinal symptoms may include
anorexia and nausea. Vascular changes may cause low
skin temperature and pallor, and there may also be
immune system effects, such as impaired T-cell and
macrophage function. Of particular concern are the effects
of the relationships among anemia, chronic kidney dis-
ease (CKD), and cardiovascular disease.
As discussed in Section I, anemia may be implicated in
several nursing home quality indicators, such as rates of
cognitive impairment, rates of decline in mobility, rates of
decline in activities of daily living, and rates of bedfast
residents.6 Thus, the finding of even mild anemia in an
elderly nursing home patient may be a good reason to
pursue the cause and consider an intervention. The
National Kidney Foundation (NKF) recommends that a
workup for anemia be initiated if Hb is less than 12 g/dL.
More than one method is available to assess anemia and
renal function7 in the elderly, and the specificity for our
population at risk continues to be debated ( Tables 1 and 2).
The basic laboratory parameters are useful in identifying
the etiology of anemia and potential for meaningful ther-
apy. In elderly patients, blood loss and nutritional defi-
ciency must be ruled out. After that, look for a multifacto-
I I . A n e m i a — Why It Is ImportantEric G. Tangalos, MD, FACP, AGSF, CMD
Figure 1: Signs and symptoms of anemia.5 Adapted from Semin Oncol.1998;25(suppl 7):2–6.
Table 1: Basic laboratory evaluation.
Table 2: Kidney function assessment.7
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rial etiology based on problems with erythropoesis. As the
molecular basis of anemia is better understood, the roles
of erythropoietin deficiency and erythropoietin resistance
associated with chronic or occult kidney disease are
assuming more importance as primary causes of anemia
in elderly patients. Anemia due to CKD can have debili-
tating effects on the patient by producing lethargy, weak-
ness, and cardiac symptoms.8
In long-term care settings, significant rates of age-related
decline in renal function have been observed. In a recent
study from Canada, nearly 40% of the residents in 87
long-term care facilities had a glomerular filtration rate
(GFR) less than 60 mL/min/1.73m2.9 The strength of the
link between rates of renal insufficiency and anemia is
also becoming clearer. A recent study in a health mainte-
nance organization of more than 220,000 adult patients
with elevated serum creatinine levels showed that as
serum creatinine rose, the risk of anemia and the severity
of anemia increased.10 Also, in a nationwide analysis of
patients who became eligible for renal dialysis due to end-
stage renal disease, 51% had anemia and only 20% of
these patients had received treatment for it before begin-
ning dialysis.11
As discussed in Section III, recent research has demon-
strated that anemia of CKD is a significant risk factor for
increased morbidity and mortality due to cardiovascular
events.12 Abnormal GFR was specifically implicated as an
independent risk factor for death from any cause, cardio-
vascular events, and hospitalization in a large (n = 1.1 mil-
lion) diverse population of adults from an integrated
health care delivery system.13
Anemia and GFR abnormalities have been associated,
independently and additively, with increased risk of mor-
tality in patients who undergo percutaneous coronary
interventions.14 Evidence is emerging on the impact of cor-
recting even mild anemia in patients with congestive
heart failure (CHF). In an open-label uncontrolled study,
179 diabetic and nondiabetic patients with severe resistant
CHF and mild anemia were treated with erythropoietin
and iron therapy for an average of 11.8 months. During
the treatment, significant improvements in heart function,
symptoms, and hospitalization rates were observed com-
pared with baseline measurements (Table 3).15 Progression
of renal failure (shown by changes in serum creatinine
levels and creatinine clearance) was also tracked. During
the treatment, significant improvement in heart function,
symptoms, and hospitalization rates were observed com-
pared with baseline measurements (Table 3), and progres-
sion of renal failure was slower during the intervention
period than during an equal period before intervention.15
The decreased rate of hospitalization should be of partic-
ular interest to the long-term care community, for whom
transitions of care will be important quality indicators.
Many laboratories now routinely report creatinine clear-
ance rates, and GFR can be calculated through a number
of medical software programs found on hand-held per-
sonal digital assistants using either the Modification of
Diet in Renal Disease or the Cockcroft-Gault equation
(Table 2). The NKF has produced a treatment algorithm
Table 3: Anemia correction may improve cardiac function and reducehospitalizations.*15 Adapted and reprinted with permission fromNephrol Dial Transplant. 2003;18:141-146.
*179 Diabetic and nondiabetic congestive hearth failure patients
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for anemia associated with CKD (Figure 2) that further
helps initiate an evaluation that will improve manage-
ment of these patients.16
The link associating anemia and CKD is becoming more
important to our practice. This combination of conditions
is a common marker for frailty and a serious problem for
the elderly. Anemia of CKD contributes to morbidity and
mortality that is especially associated with cardiovascular
disease. Correction of even mild anemia in elderly
patients may have multiple benefits. Clinically meaning-
ful outcomes for this population at risk still need to be
studied.
References
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