Also, the physical activity value was self-declared and unmeasurable, of interest but considered less reliable
than the biochemical measurements and it was also omitted from the logistic analysis.
3. Results
3
.
1
. Anthropometric measurements, smoking and BP In the present case-control study the apparently
healthy controls were compared with subjects with pre- viously undiagnosed AP regarding sex, age 40 – 60,
profession civil servants of the Governmental staff and a medium-low socioeconomic status with similar
mean years of education and a similar BMI around 25. Also, they declared that they did not drink alcohol.
There was no significant difference in the BP between these two groups Table 1 and levels were within the
reference range according to European and National Cholesterol Educational Program guidelines [34,35].
The percentages of cigarette smokers were similar in the two groups, however, the percentages of those with a
family history of CHD in first degree relatives, before age of 60, were significantly higher Table 1 in the
angina group than in the controls.
3
.
2
. Lipid profile There were no significant differences in TC and LDL
between the two groups Table 2. TG 44 and ratio of LDL-C HDL-C were significantly higher 27 in
the cases than controls Table 2 and HDL-C was significantly lower 15 in the cases than controls.
There was a significant inverse correlation between HDL and plasma TG r
s
= − 0.433, P = 0.0001. It has
been suggested that HDL-C B 1.0 mmoll andor fast- ing triglycerides \ 2.0 mmoll and TC \ 5.0 mmoll are
markers of increased coronary risk [34,35]. Seventy five percent of either angina subjects or controls had TC \
5.0 mmoll; 46 of the angina and 24 of controls had TG \ 2.0 mmoll; and 53 of angina cases and 26 of
the controls had HDL-C B 1.0 mmoll. Thus, these classical risk factors occurred at least twice as often in
the angina cases as the controls, in combination with a lower declared physical activity and an increase in the
family background of premature CHD P = 0.0055 and P = 0.0063, respectively.
Table 1 Anthropometric data and blood pressure and smoking habits in controls and subjects with previously undiagnosed angina pectoris AP, in
Tehran
a
Control Parameter
n P
Angina n
48.7 0.54 82
0.586 48.4 0.38
146 Age years
146 14.3 0.27
EDU 82
13.6 0.37 0.068
BMI 0.207
25.1 0.34 82
24.6 0.24 146
BP mmHg 82
Systolic 126.6 1.3
146 0.124
123.5 1.1 0.269
78.7 1.0 82
Diastolic 77.10 0.7
146 82
181 20 0.0055
Activity min 146
270 20 146
13.0 Smoking \5day
82 15.9
0.553 82
17.1 0.0063
146 32.9
History of CHD in the 1st relativeB60
a
Data are presented as mean S.E.M.. Education by years EDU; weight kgheight m
2
, BMI; blood pressure, BP; walking+exerciseweek. Activity min; smoking more than 5 cigarettesday considered as smoker. Data were compared with the unpaired t-test.
Data were compared by non-parametric, Wilcoxon two sample test. Data were compared by x
2
test. Table 2
Serum levels of major lipids in subjects with previously undiagnosed angina pectoris and controls, in Tehran
a
n Parameter mmoll
Angina n
P Control
146 5.78 0.09
82 6.13 0.15
0.053 TC
146 3.87 0.09
LDL-C 82
4.09 0.14 0.215
82 1.18 0.03
146 HDL-C
B 0.0001
1.01 0.04 146
B 0.0001
4.51 0.23 82
3.54 0.11 LDL-CHDL-C
146 1.61 0.07
TG 82
2.32 0.18 B
0.0001 Lpa mgdl
140 21.5 1.7
79 29.6 3.5
0.131
a
Values are presented as mean S.E.M.. Data were compared with the unpaired t-test. Total cholesterol, TC; high density lipoprotein cholesterol, HDL-C; low density lipoprotein cholesterol, LDL-C; triglyceride, TG; lipoprotein a, Lpa.
Data were compared by non-parametric Wilcoxon two sample test.
Table 3 Comparison of plasma antioxidants and oxidation indices in subjects with previously undiagnosed angina pectoris and controls in Tehran
a
Control n
Angina n
P Antioxidants mmoll
141 Vitamin C
55.6 1.9 80
51.1 2.2 0.137
24.0 0.5 77
138 26.3 1.0
a-Tocopherol 0.053
138 a-TocopherolTC mmolmmol
4.21 0.08 77
4.38 0.16 0.348
23.3 0.40 77
23.5 0.64 Yadj Vitamin E
0.820 138
2.67 0.13 77
138 2.75 0.19
g-Tocopherol 0.816
2.09 0.05 77
Retinol 1.90 0.06
138 0.025
0.391 0.03 77
138 0.352 0.03
b-Carotene 0.199
138 a-Carotene
0.061 0.007 77
0.044 0.004 0.462
0.719 0.024 77
138 0.654 0.036
Lycopene 0.118
138 b-Cryptoxanthin
0.467 0.03 77
0.398 0.04 0.041
0.266 0.007 77
0.222 0.020 0.802
Canthaxantin 138
0.659 0.023 77
138 0.618 0.032
Lutein+Zeaxanthin 0.296
0.337 0.009 77
Oxidation indices MDA mmoll 0.376 0.010
111 0.0001
0.335 0.009 77
111 0.363 0.011
YadjMDA 0.0021
315 24 Olab Uml
77 134
362 33 0.122
a
Data are presented as mean S.E.M.. Data were compared with the unpaired t-test. MDA, malondialdehyde; oLab, autoantibodies to oxidized LDL; YadjE and YadjMDA, a-tocopherol and MDA were adjusted to mmolL cholesterol and mmolL triglycerides according to Jordan
et al. [33]; Yadj = Y−B
1
x
1
− x
1,0
−B
2
x
2
− x
2,0
, 5.71 mmol TC and 1.36 mmol TG median control of this population, were taken as standard value for cholesterol and triglycerides, respectively.
Data were compared by the non-parametric Wilcoxon two sample test.
3
.
3
. Lp a
The mean level of Lpa was 37 higher P = 0.131: ns in the cases than the controls Table 2. Plasma level
of Lpa above 30 mgdl was found in 21 of controls and 33 of angina cases.
3
.
4
. Oxidation indices Indices of lipid peroxidation such as MDA were
significantly higher 12 in the cases than controls P = 0.0001, Table 3. Also, when MDA was standard-
ized for lipid [yadjMDA, which incorporated choles- terol and triglycerides [33]] it was significantly higher in
the cases than controls P = 0.0021. Circulating au- toantibodies against oLab were also 27 higher in the
cases than controls, but at marginal significance only if outlying values were excluded P = 0.049, Table 3.
There was no correlation between MDA and oLab r
s
= − 0.051, P = 0.505.
3
.
5
. Vitamin C Plasma vitamin C level was close to the optimal level
recommended to protect against CHD [19,20,34,36], with no significant differences between the cases and
controls Table 3. Plasma vitamin C was positively correlated with the number of oranges consumed per
day r = 0.271, P = 0.0001. Vitamin C was significantly correlated
with b-cryptoxanthin
r
s
= 0.372,
P = 0.0001.
3
.
6
. Lipophilic antioxidants Plasma retinol was significantly 9 lower in the
cases than in controls. b-Cryptoxanthin exhibited no- ticeable significant differences between the two groups.
The control group had significantly higher b-cryptoxan- thin 15 than in the cases Table 3. b-Cryptoxanthin
was also weakly correlated with the number of oranges consumedday r
s
= 0.217, P = 0.002. The plasma
carotene a – b-carotene seemed to be similar to the levels recorded for Austrians [22] and other European
males [21], yet b-carotene did not reach desirable rec- ommended levels [36]. The absolute amount of a-toco-
pherol was 9.6 higher in the cases than controls, the difference was not statistically significant. When a-toco-
pherol was standardized for concurrent cholesterol-rich carriers, the a-tocopherol status within lipids a-toco-
pherolTC as well as lipid standardized a-tocopherol YadjE, which incorporates cholesterol and TG [33]
the values were clearly below the recommended desir- able levels [36], but without any differences between
cases and controls Table 3. Although b-carotene did not exhibit any differences between the two groups,
levels were lower than recommended for primary pre- vention for both controls and cases [36].
3
.
7
. Multiple regression analyses Considering all the variables assessed for AP and
controls, plasma levels of retinol, b-cryptoxanthin, LDL-CHDL-C and MDA were independently associ-
ated with AP in this Iranian population Table 4. For one standard deviation S.D. increase in retinol and
log
e
b-cryptoxanthin, there was a 0.644 and 0.675-fold decrease in the odds of angina. However, for an in-
crease of one S.D. in log
e
YadjMDA and LDL-C HDL-C, there was 1.612 and 2.006-fold increase for
risk of angina, respectively.
4. Discussion
