CARDIOVASCULAR JOURNAL OF AFRICA • Vol 21, No 2, March/April 2010
AFRICA
105
inflammation in the pathogenesis of CAD.
Table 4 depicts the odds ratio of the various risk factors
analysed by univariate regression analysis. The odds ratio is the
measure of the increase in risk of the disease per unit increase
of the parameter. In univariate analysis, Lp(a) among the
lipid parameters and CRP among the inflammatory parameters
emerged as the strongest risk factors. Lp(a) had an odds ratio of
1.217 (95% confidence interval of 1.159–1.279) and CRP had an
odds ratio of 2.996 (95% confidence interval of 2.216–4.049)
Discussion
The CAD rate in Asian Indians has been increasing rapidly and
has reached alarming levels.
1-3,5
It is this CAD-prone North Indian
population that constitutes the study population in this research.
In the last decade, substantial improvements have occurred in the
assessment of cardiovascular risk. A better appreciation of the
atherogenic effects of well-known cardiovascular risk factors has
been accompanied by understanding the sum of these factors; i.e.
the global risk profile provides a better predictive power than any
single risk factor. In addition, a number of more recently identi-
fied and less well-known factors have received intense investiga-
tion over the past few years.
17-19
The current view of atherosclerosis is a chronic inflammatory
process, developing in response to some metabolic disorders,
infections and environmental processes, which initiates and
promotes lesion development to the point of acute thrombotic
complications and clinical events.
19,20
Clearly, inflammation
begets more inflammation.
21
Substantial advances in basic and
experimental science have illuminated the role of inflamma-
tion and the underlying cellular and molecular mechanisms that
contribute to atherogenesis.
22-24
Many individuals develop CAD in the absence of abnormali-
ties in the lipoprotein profile. The availability of effective thera-
pies for preventing even a first myocardial infarction renders
imperative the need to identify at-risk individuals, for concerted
intervention, before problems manifest. Based on the evidence
supporting the role of inflammation in the pathogenesis of
atherosclerosis, inflammatory markers have garnered substantial
interest as markers of atherosclerotic risk and add to the informa-
tion available from traditional measures such as lipid profiles.
25,26
In the present study, the roles of CRP and TNF-
α
were evaluated
as markers of the underlying inflammatory process in North
Indian patients with acute myocardial infarction, and their serum
levels were significantly elevated in the CAD-prone North
Indian patients with AMI, compared to controls.
One of these markers, CRP, has proven remarkably robust as a
marker of cardiovascular risk. Plasma CRP, an acute-phase reac-
tant produced primarily by the liver in response to inflammatory
cytokines such as IL-6, prospectively identifies asymptomatic
individuals at risk for coronary events.
27
The pro-atherogenic
functions of CRP include induction of production of inflamma-
tory cytokines and chemotaxis of monocytes, increased expres-
sion of cell adhesion molecules, down-regulation of endothelial
TABLE 1. CLINICAL CHARACTERISTICS
OF STUDY GROUPS
AMI patients
(
n
=
150)
Controls
(
n
=
150)
Age (years)
55.1
±
9.6
53.7
±
10.2
BMI (kg/m
2
)
23.2
±
4.2
22.5
±
3.9
Systolic BP (mmHg)
128
±
9.4
121
±
10.1
Diastolic BP (mmHg)
78
±
4.5
75
±
5.2
Smoking (
n
)
10
6
Alcohol intake (
n
)
6
4
Past history of CAD
0
0
Family history of CAD
0
0
TABLE 2. BIOCHEMICAL PARAMETERS
IN THE STUDY GROUPS
Parameter
Patients
(
n
=
150)
Controls
(
n
=
150)
p
-value
Total cholesterol (mg/dl) 188.6
±
40.15 145.5
±
29.71
<
0.001
Triglycerides (mg/dl)
143.3
±
64.83 123.2
±
41.92
<
0.001
HDL (mg/dl)
38.2
±
6.29 43.2
±
5.57
<
0.001
LDL (mg/dl)
133.9
±
32.11 79.7
±
20.23
<
0.001
Lp(a) (mg/dl)
40.2
±
6.54 10.5
±
2.34
<
0.001
Apo-A (mg/dl)
107
±
19.37 109.1
±
18.69 NS
Apo-B (mg/dl)
99.6
±
23.55 76.9
±
22.62
<
0.001
TNF-
α
(pg/ml)
86.9
±
14.76 15.2
±
4.23
<
0.001
CRP (mg/l)
5.01
±
1.99 1.20
±
0.28
<
0.001
NS: not significant.
TABLE 3. SPEARMAN CORRELATION OF THE
INFLAMMATORY MARKERSWITHTHE LIPID
PARAMETERS IN PATIENTSWITHAMI
Inflammatory parameter Lipid parameters
r
-value
p
-value
TNF-
α
v/s
Cholesterol
0.058
NS
Triglycerides
–0.076
NS
LDL
0.175
NS
HDL
–0.127
NS
Apo-AI
–0.031
NS
Apo-B
0.018
NS
Lp(a)
0.698
0.003
CRP v/s
Cholesterol
0.070
NS
Triglycerides
0.159
NS
LDL
0.047
NS
HDL
–0.023
NS
Apo-AI
0.107
NS
Apo-B
–0.070
NS
Lp(a)
0.714
0.001
NS: not significant.
TABLE 4. UNIVARIATE REGRESSIONANALYSIS OF RISK
FACTORS FOR CAD
Parameter
Exp (
β
)
95% CI
p
-value
Cholesterol
1.032
1.021–1.044
0.000
Triglycerides
1.007
1.002–1.013
0.012
LDL
1.032
1.020–1.043
0.000
HDL
0.899
0.855–0.945
0.000
Apo-AI
0.991
0.977–1.006
0.258
Apo-B
1.040
1.025–1.056
0.000
Lp(a)
1.217
1.159–1.279
0.000
TNF-
α
1.108
1.055–1.163
0.000
CRP
2.996
2.216–4.049
0.000
