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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 27, No 4, July/August 2016
246
AFRICA
High aortic pulse-wave velocity may be responsible for
elevated red blood cell distribution width in overweight
and obese people: a community-based, cross-sectional
study
Ibrahim Halil Altiparmak, Muslihittin Emre Erkus, Aydemir Kocarslan, Hatice Sezen, Ozgur
Gunebakmaz, Yusuf Sezen, Zekeriya Kaya, Ali Yildiz, Recep Demirbag
Abstract
Background:
Obesity and overweight are risk factors for
atherosclerosis. Red blood cell distribution width (RDW) is
associated with subclinical cardiac diseases. The aim of this
study was to investigate the association between RDW and
aortic stiffness in overweight or obese subjects.
Methods:
A total of 101 overweight or obese subjects with-
out overt cardiovascular disorders, and 48 healthy controls
were enrolled. RDW, aortic pulse-wave velocity (PWV) and
augmentation index 75 (Aix75) were evaluated. The case
subjects were divided into two sub-groups according to PWV
values;
≥
10 m/s in group I, and
<
10 m/s in group II. Bivariate
correlation and multiple regression analyses (stepwise) were
performed.
Results:
RDW and PWV were considerably increased in
the case groups compared with the controls. RDW was
significantly increased in group I compared with group II
and the controls [median 12.0 m/s, interquartile range (IQR):
10.5–17.5; median 11.7 m/s, IQR: 10.2–14.2, and median 11.4
m/s, IQR: 9.6–15.5,
p
<
0.05, respectively]. Resting heart rate
and age were higher in group I than group II (81
±
11 vs 74
±
12 beats/min and 41
±
120 vs 36
±
9 years, respectively,
p
<
0.05). Regression analyses revealed that while log-RDW, age
and resting heart rate were independent predictors for aortic
PWV, log-RDW was the most important predictor in the final
model.
Conclusions:
RDW, resting heart rate and age indepen-
dently predicted arterial stiffness, and RDW may be useful to
provide an early recognition of subclinical atherosclerosis in
overweight and obese individuals.
Keywords:
erythrocyte indices, vascular stiffness, overweight,
obese
Submitted 18/9/15, accepted 19/1/16
Published online 19/2/16
Cardiovasc J Afr
2016;
27
: 246–251
www.cvja.co.zaDOI: 10.5830/CVJA-2016-005
In addition to traditional risk factors, overweight and obesity
are important risk factors for the development of atherosclerosis
and cardiovascular events.
1
Previous studies demonstrated that
arterial stiffness (AS) was impaired in these populations.
2
AS,
which is a result of functional and structural disorders of the
arterial wall, signifies end-organ damage and increased risk of
cardiovascular events.
3
Several indicators provide valuable information about
AS. Among these, aortic pulse-wave velocity (PWV) and
augmentation index occupy an important place. Many studies
have demonstrated that aortic PWV is associated with subclinical
coronary atherosclerosis, significant coronary artery disease,
hypertension and kidney disease, and it has a predictive value for
cardiovascular events.
3-6
Red cell distribution width (RDW), part of a routine complete
blood count, is a laboratory evaluation of the variability in
the volume and size of circulating erythrocytes. It is usually
used for a differential diagnosis of anaemia.
7,8
Many recent
studies have revealed relationships between high RDW levels
and adverse cardiovascular conditions, such as heart failure,
9
severity and complexity of coronary artery disease,
10
coronary
slow flow,
11
isolated coronary artery ectasia,
8
acute myocardial
infarction,
12
and lack of coronary collateral vessels in acute
coronary syndromes.
7
The exact mechanisms causing elevated
RDW are uncertain in these clinical events. However, it has been
asserted that inflammation and oxidative stress may be possible
pathophysiological mechanisms underlying increased RDW
levels in cardiovascular diseases.
11
To our knowledge, the association of RDW with the markers
of AS in overweight and obese individuals is unknown. The aim
of the study was to determine whether there was any relationship
between RDW and AS in this population.
Department of Cardiology, Faculty of Medicine, Harran
University, Sanliurfa, Turkey
Ibrahim Halil Altiparmak, MD,
ihaltiparmak@gmail.comMuslihittin Emre Erkus, MD
Ozgur Gunebakmaz, MD
Yusuf Sezen, MD
Zekeriya Kaya, MD
Recep Demirbag, MD
Department of Cardiovascular Surgery, Faculty of
Medicine, Harran University, Sanliurfa, Turkey
Aydemir Kocarslan, MD
Department of Clinical Biochemistry, Faculty of Medicine,
Harran University, Sanliurfa, Turkey
Hatice Sezen, MD
Department of Cardiology, Faculty of Medicine, Hacettepe
University, Ankara, Turkey
Ali Yildiz, MD