Objectives:
This
study was designed to determine whether the National Cholesterol Education
Program (NCEP) lipid guidelines accurately identify subclinical atherosclerosis
and whether low-density lipoprotein cholesterol (LDL-C) and high-density
lipoprotein cholesterol (HDL-C) levels are related to the extent and prematurity
of coronary artery disease (CAD) as determined by electron beam tomography (EBCT).
Method:
930 consecutive asymptomatic subjects, without clinical CAD
and on no lipid-lowering agents, underwent EBCT. Calcium score and
percentile were correlated with total cholesterol (TC), LDL-C, HDL-C,
triglycerides, and demographic parameters.
Results:
|
n
= 930, asymptomatic patients
|
EBCT
positive: Calcium > 0
|
EBCT
negative: Calcium = 0
|
P
value
|
|
%
of patients
|
55
%
|
45
%
|
|
|
Mean
age
|
58
+ 10.5
|
49.3
+ 9.7
|
P
= 0.0001
|
|
Total
cholesterol, mg/dl
|
218
+ 39
|
211
+ 41
|
P
= 0.006
|
|
LDL
cholesterol, mg/dl
|
136
+ 36
|
127
+ 27
|
P
= 0.005
|
|
Total
cholesterol / HDL cholesterol
|
4.6
+ 1.4
|
4.2
+ 1.5
|
P
= 0.0001
|
|
HDL
cholesterol, mg/dl
|
52.2
+ 17.6
|
55.4
+ 19.3
|
P
= 0.008
|
In
the EBCT+ group, 75.1% of subjects had LDL-C <160 mg/dl and would not be
advised to use lipid-lowering medications according to NCEP guidelines.
In
subjects with LDL-C <160 mg/dl, 51.8% of subjects were EBCT+, as
were 46.1% of those with LDL-C <100 mg/dl.
There
were no significant differences in the calcium scores throughout the entire
range of all lipid parameters; calcium percentiles were virtually identical
within lipid value subgroups.
Conclusion:
We
conclude that asymptomatic patients with EBCT-defined subclinical atherosclerosis
are not reliably identified by NCEP guidelines, and TC, LDL-C, HDL-C, TC/HDL-C,
and triglyceride levels do not correlate with either the extent or prematurity
of calcified plaque burden.
