CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 4, May 2012
198
AFRICA
was no difference between the two groups regarding HTN (OR
=
1.25; 95% CI: 0.732–2.14,
p
=
0.41), hypercholesterolaemia
(OR
=
1.04; 95% CI: 0.60–1.78,
p
=
0.86), hypertriglyceridaemia
(OR
=
1.18; 95% CI: 0.62–2.25,
p
=
0.62) and cigarette smoking
(OR
=
0.63; 95% CI: 0.37–1.06,
p
=
0.08). The frequency of
cardiovascular risk factors in both groups is presented in Fig. 1.
Regarding the extent of CAD, multi-vessel disease was
more frequent than single-vessel disease in the diabetics
than the non-diabetics (89.1 and 10.9% vs 61 and 39%,
respectively,
p
<
0.0001). In hypercholestrolaemic compared to
non-hypercholestrolaemic patients, the trend was in favour of
more multi-vessel disease but the difference was not statistically
significant (76 and 24% vs 63.4 and 36.6%, respectively,
p
=
0.052). Hypertriglyceridaemia, HTN and cigarette smoking had
no impact on the extent of coronary artery involvement in terms
of multi-vessel versus single-vessel disease. The relationship of
these cardiovascular risk factors to the extent of coronary artery
involvement is presented in Table 2.
Discussion
Although the relationship between cardiovascular risk factors
and CAD has held investigators’ attention for a long time, there
are no clear data regarding the impact of risk factors on the site,
extent and complexity of coronary artery involvement in terms
of proximal or distal and diffuse or segmental involvement.
Most studies that have been conducted in this regard were based
on index of atheroma burden and extension score of CAD in
patients with DM. In the majority of these studies, a strong
relationship between DM and increased index of atheroma
burden and extension score have been reported.
1,2,4,5,7
However
Pajumen
et al
. in their study did not find any relationship
between diabetes and extent of CAD compared to non-diabetics.
8
Uddin
et al
.
1
and Synkija
et al
.
2
studied site of coronary artery
involvement (proximal versus distal involvement) in diabetic
patients versus non-diabetics. Although the trend was towards
proximal involvement in diabetic patients, it was not statistically
significant (
p
>
0.05).
Synkija reported more multi-vessel disease in hypertensive
patients than in non-hypertensives (
p
<
0.0003).
2
Hong
et al
.
9
also reported more multi-vessel than single-vessel disease in
hypertensive patients (
p
<
0.01). However, Sposito
et al
.
10
did
not find any relationship between hypertension and extent of
coronary artery involvement (multi-vessel disease), which was
similar to what we found in our study.
Synkija
et al.
2
and Sposito
et al
.
10
found no relationship
between hypercholesterolaemia and extent of CAD. Syvanne
et
al
.,
5
Kosuge
et al
.
6
and Hong
et al
.
9
reported a relationship between
low-density lipoprotein cholesterol and total cholesterol:high-
density lipoprotein cholesterol ratio and extent of coronary
artery involvement, based on ABI or index of extent of artery
involvement (
p
=
0.027,
p
=
0.01 and
p
<
0.01, respectively), but
not to the site of coronary artery involvement (proximal versus
distal).
In the study of Sposito
et al
.,
10
post-menopausal women with
hypertrygliceridaemia had more extensive CAD compared to
those without hypertrygliceridaemia (
p
=
0.0013). Wilson
et al
.
11
reported more extensive coronary artery involvement in smokers
compared to non-smokers based on score of extent of artery
involvement (
p
<
0.005), which was opposite to what we found
in our study.
None of these studies assessed relationship between
hypertriglyceridaemia or cigarette smoking and site of coronary
artery stenosis (proximal versus distal stenosis). In our study
the trend was towards distal stenosis in smokers compared to
non-smokers but it was not statistically significant (
p
=
0.08).
Also we did not find a relationship between hypertriglyceridaemia
and hypertension and the site of coronary involvement (
p
=
NS).
Uddin
et al.
1
and Synkija
et al
.
2
were the only investigators
who considered relative frequency of proximal versus distal
involvement in their patients. According to their findings,
TABLE 1. CLINICALAND DEMOGRAPHIC
CHARACTERISTICS OF PATIENTS
Demographic characteristics
Case group
n
=
125
(100%)
Control group
n
=
125
(100%)
p
-value
Males,
n
(%)
87 (69.6)
95 (76)
NS
Age mean
±
SD (years)
59.6
±
10.8 58.8
±
10.9 NS
Diabetes mellitus,
n
(%)
42 (33.6)
13 (10.4)
<
0.0001
Hypertension,
n
(%)
42 (33.6)
36 (28.8)
NS
Hypercholesterolaemia,
n
(%)
38 (30.4)
37 (29.6)
NS
Hypertriglyceridaemia,
n
(%)
24 (19.2)
21 (16.8)
NS
Cigarette smoking,
n
(%)
36 (28.8)
49 (39.2)
0.08
TABLE 2. RELATIONSHIP BETWEEN CARDIOVASCULAR
RISK FACTORSAND EXTENT OF CORONARY
ARTERY DISEASE
Extent of CAD
Subgroups
Single-vessel
disease
n
(%)
Multi-vessel
disease
n
(%)
p
-value
Diabetic
6 (10.9)
49 (89.1)
<
0.0001
Non-diabetic
76 (39)
119 (61)
Hypertensive
20 (25.6)
58 (74.4)
NS
Non-hypertensive
62 (36)
110 (64)
Hypercholesteraemic
18 (24)
57 (76)
0.052
Non-hypercholestraemic
64 (36.6)
111 (63.4)
Hypertriglyceridaemic
12 (26.7)
33 (73.3)
NS
Non-hypertriglyceridaemic 70 (34.1)
135 (65.9)
Cigarette smoker
31 (36.5)
54 (63.5)
NS
Non-cigarette smoker
51 (30.9)
114 (69.1)
DM
=
diabetes mellitus
HTN
=
hypertension
HCL
=
hypercholesterolaemia
HTG
=
hypertriglyceridaemia
C/S
=
cigarette smoking
Fig. 1. Frequency of cardiac risk factors in the two groups.
60
50
40
30
20
10
0
DM
HTN
HCL
HTG
C/S
42
33.6%
13
10.4%
42
33.6% 36
28.8%
38
30.4% 37
29.6%
24
19.2% 21
16.8%
36
28.8%
49
39.2%
case group
control group
