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RESEARCH ARTICLE
SA JOURNAL OF DIABETES & VASCULAR DISEASE
62
VOLUME 14 NUMBER 2 • DECEMBER 2017
Neutrophil/lymphocyte (N/L) ratio was calculated by dividing the
total neutrophil count by the lymphocyte count.
High-sensitivity C-reactive protein (hs-CRP) analyses were done
using the immunonephelometry method (Dade Behring, Inc, BN
Prospect, Marburg, Germany). Serum levels of creatinine, fasting
blood glucose, triglycerides, total cholesterol, and low- and high-
density lipoprotein cholesterol were measured using conventional
methods.
A conventional angiography device (Artis zee; Siemens, Erlangen,
Germany) was used for coronary angiography. Angiograms were
evaluated qualitatively by two different experts, and mean values
were used to assess the rate of stenosis. Patients with atherosclerotic
lesions in any of the coronary arteries were diagnosed as having
CAD. Obstructive CAD was defined as stenosis of ≥ 50% of
the diameter of a major epicardial or branch vessel > 2.0 mm in
diameter.
Gensini scores were calculated for each patient as previously
defined.
14
Triple-vessel disease was defined as stenosis of ≥ 50%
in each of the major vessels or their major branches. Patients were
evaluated and treated according to the current guidelines.
Statistical analysis
Statistical analysis was performed using commercial software (IBM
SPSS Statistics 22, SPSS Inc, Chicago, IL, USA). After performing
the Kolmogorov–Smirnov normality test, two independent-sample
t
-tests were used to compare the normally distributed independent
variables, and the Mann–Whitney
U
-test was used to compare
the non-normally distributed independent variables between
the two groups. For normally distributed variables, mean and
standard deviation (SD) are listed, otherwise, median values are
given. To analyse the categorical data, a chi-squared test was used.
Categorical data are expressed as numbers and percentages.
A receiver operating characteristic (ROC) curve was constructed
for RDW to test the effectiveness of various cut-off points in
predicting CAD. The area under the ROC curve was calculated;
the sensitivity and specificity for the RDW of the most appropriate
cut-off point were calculated for predicting CAD. Correlations
were determined using the Spearman test. A
p
-value < 0.05 was
considered statistically significant.
Table 1.
Baseline characteristics and laboratory findings of the study
groups
CAD–
CAD+
Variables
(
n
= 109)
(
n
= 124)
p
-value
Age (years)
58.6 ± 8.0
57.7 ± 9.0
0.387
Gender (male)
61 (56)
68 (55)
0.895
Hypertension
93 (85)
104 (84)
0.856
Dyslipidaemia
61 (56)
77 (62)
0.353
Smoking
14 (13)
24 (20)
0.215
Aspirin
72 (66)
93 (75)
0.150
Clopidogrel
0 (0)
23 (19)
< 0.001
RAS blockers
70 (64)
93 (75)
0.086
β
-blockers
34 (31)
66 (53)
0.001
Calcium channel blockers
20 (18)
23 (19)
1.000
Statins
30 (28)
43 (38)
0.260
Body mass index (kg/m
2
)
28.7 ± 5.0
28.3 ± 4.5
0.536
Systolic blood pressure (mmHg)
130 ± 13
132 ± 14
0.144
Diastolic blood pressure (mmHg)
78 ± 9
79 ± 8
0.627
Glucose (mg/dl)
166 ± 75
174 ± 78
0.416
[mmol/l]
[9.21 ± 4.16]
[9.66 ± 4.33]
Creatinine (mg/dl)
0.73 ± 0.18 0.71 ± 0.28 0.630
[μmol/l]
[64.53 ± 15.91] [62.76 ± 24.75]
Uric acid (mg/dl)
4.5 ±1.4
4.9 ± 1.7
0.081
hs-CRP (mg/l)
5.12 ± 2.93 6.07 ± 4.83 0.348
Total cholesterol (mg/dl)
197 ± 40
199 ± 49
0.726
[mmol/l]
[5.10 ± 1.04]
[5.15 ± 1.27]
Triglycerides (mg/dl)
187 ± 86
191 ± 138
0.786
[mmol/l]
[2.11 ± 0.97]
[2.16 ± 1.56]
LDL cholesterol (mg/dl)
120 ± 36
122 ± 44
0.688
[mmol/l]
[3.11 ± 0.93]
[3.16 ± 1.14]
HDL cholesterol (mg/dl)
46 ± 11
45 ± 13
0.283
[mmol/l]
[1.19 ± 0.28]
[1.17 ± 0.34]
WBC (103 cells/µl)
7.0 ± 1.9
7.2 ± 2.0
0.407
Haemoglobin (g/dl)
13.1 ± 1.1
13.1 ± 1.6
0.757
RDW (%)
12.5 ± 1.5
13.8 ± 1.7 < 0.001
MPV (fl)
8.43 ± 1.10 8.59 ± 1.02 0.265
Neutrophil/lymphocyte ratio (%) 2.26 ± 1.37 2.52 ± 1.94 0.457
CAD: coronary artery disease, CAD–: patients with normal coronary arteries,
CAD+: patients with coronary artery disease, RAS: renin–angiotensin system,
hs-CRP: high-sensitivity C-reactive protein, LDL: low-density lipoprotein,
HDL: high-density lipoprotein, WBC: white blood cells, RDW: red cell distribu-
tion width, MPV: mean platelet volume. Data are shown as n (%) or mean
± SD
Table 2.
Baseline characteristics and laboratory findings of low and high
RDW groups
Low RDW High RDW
(≤ 13.25)
(> 13.25)
Variables
(
n
= 46)
(
n
= 78)
p
-value
Age (years)
56.7 ± 8.0
58.2 ± 9.5
0.381
Gender (male)
27 (59)
41 (53)
0.318
Hypertension
38 (83)
66 (85)
0.478
Dyslipidaemia
29 (63)
48 (61)
0.511
Smoking
5 (11)
19 (24)
0.052
Aspirin
33 (72)
60 (77)
0.331
Clopidogrel
11 (24)
12 (15)
0.173
RAS blockers
32 (70)
61 (78)
0.195
β
-blockers
28 (61)
38 (49)
0.130
Calcium channel blockers
9 (20)
14 (18)
0.501
Statins
13 (28)
30 (39)
0.169
Body mass index (kg/m
2
)
28.8 ± 4.5
28.0 ± 4.5
0.363
Systolic blood pressure (mmHg)
131 ± 13
133 ± 15
0.328
Diastolic blood pressure (mmHg)
78 ± 8
79 ± 8
0.196
Glucose (mg/dl)
163 ± 77
181 ± 79
0.207
[mmol/l]
[9.05 ± 4.27]
[10.05 ± 4.38]
Creatinine (mg/dl)
0.63 ± 0.17 0.76 ± 0.31 0.008
[μmol/l]
[55.69 ± 15.03] [67.18 ± 27.40]
Uric acid (mg/dl)
4.6 ± 1.5
5.1 ± 1.7
0.213
hs-CRP (mg/l)
4.11 ± 1.88 7.12 ± 5.58 0.043
Total cholesterol (mg/dl)
195 ± 44
202 ± 52
0.481
[mmol/l]
[5.05 ± 1.14]
[5.23 ± 1.09]
Triglycerides (mg/dl)
197 ± 173
188 ± 114
0.736
[mmol/l]
[2.23 ± 1.95]
[2.12 ± 1.29]
LDL cholesterol (mg/dl)
114 ± 33
127 ± 48
0.088
[mmol/l]
[2.95 ± 0.85]
[3.29 ± 1.24]
HDL cholesterol (mg/dl)
46 ± 15
44 ± 12
0.461
[mmol/l]
[1.19 ± 0.39]
[1.14 ± 0.31]
WBC (103 cells/µl)
7.1 ± 1.9
7.3 ± 2.2
0.516
Haemoglobin (g/dl)
13.3 ± 1.5
13.0 ± 1.6
0.454
RDW (%)
12.9 ± 0.7
14.3 ± 1.4
0.001
MPV (fl)
8.35 ± 1.13 8.72 ± 0.93 0.049
Neutrophil/lymphocyte ratio (%) 1.92 ± 0.07 2.89 ± 2.33 0.009
RDW: red cell distribution width, RAS: renin–angiotensin system, hs-CRP: high-
sensitivity C-reactive protein, LDL: low-density lipoprotein, HDL: high-density
lipoprotein, WBC: white blood cells, MPV: mean platelet volume.
Data are shown as n (%) or mean ± SD