The SA Journal Diabetes & Vascular Disease Vol 14 No 2 (December 2017)

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RESEARCH ARTICLE SA JOURNAL OF DIABETES & VASCULAR DISEASE
64 VOLUME 14 NUMBER 2 • DECEMBER 2017
anisocytosis and poor prognosis in patients with CAD. Factors
impairing bone marrow haematopoiesis are probably identical
to those that worsen the prognosis in CAD. These factors are
anaemia, iron deficiency, lipid disorders, chronic inflammation,
neurohumoral activation, glycaemic disturbance, vitamin D3
deficiency, oxidative stress and renal failure.17,18 Additionally, red
cell deformability diminution may result in impaired flow through
the microcirculation.17
Previous studies have shown an association between RDW and
the severity of CAD.11-13 Akin et al. investigated the association of
RDW with the severity of CAD in acute myocardial infarction and
showed that higher RDW values were correlated with higher Syntax
scores, which means more complex coronary lesions. They found
that after multiple logistic regression analysis, RDW remained a
significant predictor for the severity of CAD.11 Isik et al. evaluated
this relationship in patients with stable angina pectoris and found
an independent association between RDW and the complexity of
CAD, which was determined with Syntax scores.12
A large Chinese cohort study with 677 subjects showed
significantly elevated RDW values in CAD patients and a positive
correlation between RDW and the Gensini score.13 They also
found that a RDW value of 12.85% was an effective cut-off point
for predicting CAD, with a sensitivity of 50% and a specificity
of 65%. Recently, Sahin et al. concluded that RDW values were
independently associated with a high Syntax score but were not
associated with long-term mortality in patients with non-ST-
elevation myocardial infarction.19
In agreement with the current literature, we found that
elevation in RDW values was associated with both the presence
and complexity of CAD. Furthermore, we found that an RDW
value of 13.25% was an effective cut-off point in order to
determine the presence of CAD. Moreover, our study is the first to
show an association between RDW and CAD severity in a diabetic
population.
Chronic inflammation and neurohumoral activation are
thought to be the key factors for both a worse cardiovascular
prognosis and more complex coronary lesions.17,18 In our study,
hs-CRP levels were similar in the two CAD groups, but there was a
positive correlation between RDW and hs-CRP. Unfortunately, we
did not measure brain natriuretic peptides, which are markers of
the neurohumoral pathway. Some researchers demonstrated that
elevated mean platelet volume (MPV) was associated with acute
coronary syndromes, thrombosis and inflammation.20,21 We also
found a positive relationship between RDW and MPV.
It is well known that there is a link between glycaemic
disturbance and high RDW values. Two different studies showed
a relationship between glycosylated haemoglobin and RDW in an
unselected elderly population and in healthy adults.22,23 Garg et al.
demonstrated that glycosylated haemoglobin was an independent
predictor of CAD severity in a non-diabetic population.24 Our
findings support the results of previous studies.
This study has some limitations. First, we did not measure
some factors that might have influenced RDW levels, such as
vitamin B 12, folate and iron levels. Second, cardiovascular events
were not analysed due to the cross-sectional nature of the study.
Third, the relationship between RDW, glycaemic disturbance and
the severity of CAD could have been better understood if we had
analysed glycosylated haemoglobin levels. Lastly, the diagnosis
of DM was based on a previous history instead of biochemical
results.
Conclusion
RDW values were significantly higher in diabetic than non-
diabetic patients with CAD. Higher RDW values were related to
more extensive and complex coronary lesions, suggesting that
RDW may be a marker for predicting CAD severity in patients
with DM.
References
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NAM NS2 12/7.1.3/0223, 0224. For full prescribing information, refer to the package insert approved by the
Medicines Control Council, 06 April 2017. 1)Database of Medicine Prices (11 September 2017). Department of
Health website. - Accessed on 11 September 2017. DBC325/09/2017.
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