Klinisk Biokemi i Norden Nr 2, vol. 6, 1994 - page 20

Results
During the foliow-up period of 8.6 years, 104 of the
1332study subjects had fatal or non-fatal myocardial
infarction. Table I shows that Cox multivariale
regression analysis established that age, total se–
rum cholesterol, triglycerides, systolic blood
pressure and apalipoprotein (a) were significant
independent risk factors, whereas apalipoprotein
A-I was a significant protective factor. Apalipo–
protein B was significant if substituted for total
serum cholesterol but did not increase predielive
power if cholesterol was already included in the
calculation. A strong correlation (r=0.8) was found
between apo-B and total serum cholesterol but on!y
a weak correlation was seen between other para–
meters. Because of the skewed distribution of apo
(a) a logarithmic transformation was used in the
calculation.
Table I shows also the odds ratios for myocardial
infarction illustrating the relative strength of each
risk factor, showing that total cholesterol and
apalipoprotein A-I are the strongest risk factors but
in the opposite direction.
Table I
Mean total serum cholesterol and apolipoprotein
(a) values were significantly higherfor the 19% of
partidpants who had a familyhistory of coronary
artery disease (240 vs. 234mg/dl and 209 vs. 167
UlL respectively). However, other analysed risk
factors did not achieve statistical significance in
this respect.
Discussion
Our study showed a strong correlation between
apalipoprotein B and total serum cholesterol (r=0.8)
which is of no surprise since apalipoprotein B is the
chief protein in low density lipoprotein, whereas
apolipoprotein B constitutes lessthan 10% of other
lipoproteins. [10, 11] .
lt
was therefore no surprise
that apolipoprotein B was found to be a strong
predictor ofcoronary artery diseasewhen substituted
for serum cholesterol, but only when cholesterol
was not already included in the calculation. In
multivariale analysis it gave way to serum choles–
terol.
Odds ratios per standard deviation from the mean risk factor levels for fatal or nonfatal myocardial
infarction in the entire group of subjects surveyed. The dagger indicates that total serum cholesterol was
not included in the calculations.
Mean value ± SD
Patients
Control subjects
Odds ratio
p value
(n=104
(n=1228)
!SD
Age (years)
60± 8
56± 8
1.45
<
0.001
Systolic blood pressure (mm Hg) 147.5 ± 25 138.4 ± 21
1.22
0.04
Total cholesterol (mmol!L)
6.4 ±l.
O
6.06 ± 1.0
1.46
<
0.001
Apo-B (g!L)•
1.05 ± 0.27 0.94 ± 0.27
1.32
<
0.001
Apo (a) (UlL)
230 ± 275
170 ± 225
1.22
0.01
Log apo (a)
4.61 ± 1.6
4.07 ± 1.8
1.32
0.01
Apo-A-I
(g/L)
1.63 ± 0.25 1.73 ± 0.28
0.70
<
0.001
Triglycerides (mmol/L)
1.57 ± 1.2
1.34 ± 0.8
1.22
0.03
Smoking score
1.76 (0.55) 1.70 (0.50)
0.06
50
Klinisk kemi
i
Norden Z, 1994
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