Anaemia and Rheumatoid Arthritis
Anaemia
is known to be common in rheumatoid arthritis, deriving both from long term use
of NSAIDs and anaemia of chronic disease often associated with infection,
inflammation, or malignancy. How common anaemia is in rheumatoid arthritis has
been investigated by a systematic review [1], which also sought evidence about
the effects of treating the anaemia.
Systematic review
Good
searching strategies were continued to February 2003. Outcomes of interest were
prevalence of anaemia, as well as the impact of anaemia on a range of clinical
and functional outcomes, and quality of life.
Results
In
all 19 studies were included, all of them relatively small.
Prevalence
Ten
studies with 623 adult patients with rheumatoid arthritis and 213 with juvenile
arthritis reported on prevalence, using different criteria for anaemia. Some
reported anaemia in total, some by severity, and some by sex. In the nine
studies with adult patients with rheumatoid arthritis, prevalence ranged from
30% to 93%, with an overall prevalence of 54% (Figure 1). In juvenile arthritis
it was 41%. There was insufficient information for sensible further breakdown
of the figures.
Figure 1: Prevalence of investigator diagnosed anaemia in individual cohorts of patients with rheumatoid arthritis
Outcomes
Only
small numbers of small studies reported outcomes associated with anaemia. Based
on the information available, anaemia has little apparent impact on morning
stiffness, swollen joints, Ritchie index, or pain. There may be improvements in
muscle strength if anaemia is corrected, based on tiny numbers.
However,
increasing haemoglobin levels in patients with rheumatoid arthritis and anaemia
is probably beneficial in other ways. Three studies all suggested good
improvements in energy levels, and another three studies indicated positive
changes in quality of life measures.
Comment
This
is a surprisingly small amount of evidence given that rheumatoid arthritis is
not uncommon, that considerable efforts have gone into improving treatments,
that anaemia is acknowledged to be a problem in the condition, and that it is
seen by some as a model for the anaemia of chronic diseases.
Reference:
- A Wilson et al. Prevalence and outcomes of anemia in rheumatoid arthritis: a systematic review of the literature. American Journal of Medicine 2004 116 (7A): 50S-70S.