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J. David Schnatz, M.D.
Director, Lipid Education Service
Saint Francis Hospital and Medical Center
114 Woodland Street, Hartford, CT 06105
Telephone: (860) 714-5555
September/October 2001
On May 16th, NCEP published its third set of lipid control guidelines
from the Adult Treatment Panel (ATP-III). The first set of guidelines
emphasized prevention of coronary artery disease (CAD) in patients with
elevated LDL (1). The second affirmed the earlier guidelines and added
intensive therapy of patients with CAD so as to treat to an LDL of  100
(2). These guidelines also emphasized age as a risk factor and introduced
the importance of HDL, particularly a value of  60
being a negative risk factor.
Based on a good deal of new clinical evidence, ATP-III (3) continues
to emphasize LDL, considers an optimal LDL to be <100 mg/dl in all
persons, equates the risk of diabetes mellitus with that of CAD, individualizes
specific risk, raises the lower limit of HDL, lowers the upper limit of
TG and identifies patients with the metabolic syndrome as needing intensive
lifestyle changes. The specific points made in the ATP-III recommendations
are:
Screening:
- All adults, age 20 and older, should be screened every 5 years, using
a fasting lipid profile, consisting of CHOL, LDL, HDL and TG. Previously,
it was recommended that a non-fasting sample be measured for CHOL and
HDL, and, if these were abnormal, a complete profile be done on a fasting
sample. This remains an option, but only if it is difficult to get a
fasting sample. The frequency of measurement changes, once an abnormality
is found or other risk factors are identified.
Risk Assessment: (LDL is not counted as a risk factor since the
major purpose is to lower LDL).
- Patients with CAD remain in the highest risk category.
- The risk for patients with diabetes mellitus (DM) has been equated
with that of CAD, since it has been shown that patients with DM and
no CAD have the same risk as those with CAD and no DM.
- Other CAD risk equivalents are generalized macro vascular disease
and 10 year CAD risk of >20%.
- For patients without clinical CAD, projections of 10 year risk individualize
risk assessment to assist in determining those patients in whom to intensify
therapy. ATP-III uses a modification (4) of the Framingham Risk Prediction
Score (5) since diabetes has been elevated to a CAD equivalent and is
not considered in the risk factors that influence intensiveness of therapy.
- Exclusive of the risk factors already mentioned, ATP-III continues
to consider the following classical risk factors in setting goals: cigarette
smoking, hypertension (BP140/90
or on anti-hypertensive medication), low HDL (<40 mg/dl), FH of premature
CAD (male first degree relative <55 and female <65) and age (male
45, female
55).
- Sets levels of LDL goals based on above risks: CAD and CAD risk equivalents,
<100 mg/dl; two or more risk factors, <130 mg/dl and 0-1 risk
factor, <160 mg/dl.
- Recommends clinical recognition of the metabolic syndrome as a special
category of patients at risk. This includes patients who have three
or more of the following: abdominal obesity (waist circumference >40"
in men, 37-40" in some, and >35" in women), elevated TG
(150
mg/dl), low HDL (<40 mg/dl in men and <50 mg/dl in women), hypertension (130/85
mm/Hg) and elevated fasting glucose (110
mg/dl).
Modification of Target Lipid Levels:
- Optimal LDL is <100 mg/dl, near or above optimal is 100-129, borderline
high is 130-159, high is 160-189 and very high is 190
mg/dl.
- Raised the lower limit of HDL so that <40 mg/dl is low.
- Lowered the upper limit of TG so that 150
mg/dl is high.
- Further defined TGs of 150-199 mg/dl as borderline high, 200-499
as high and 500
as very high.
Therapeutic Goals for LDL:
- Relation of risk to goals and initiation of therapy.
| |
|
LDL Initiation Level For: |
| Risk |
LDL Goal |
Lifestyle Changes |
Drugs |
CAD or CAD equivalent
(10 year risk >20%) |
<100 |
100
|
130
100-129 optional |
| |
|
|
|
2+ Risk Factors
(10 year risk 20%)
|
<130 |
130 |
10 year risk 10-20% : 130
10 year risk <10% : 160
|
| |
|
|
|
| 0-1 Risk Factor |
<160 |
160 |
190
160-190 optional |
Therapeutic Lifestyle Changes (TLC)
Nutrient composition of diet: Strictly limits saturated fat (<7% daily
intake), sets cholesterol intake at <200mg day and total Fat at 25-35%
of daily energy intake. Adds plant stanol/sterol esters (2g/day) and soluble
fiber (10-25g/day). Increases emphasis on caloric intake and weight control,
coupled with physical activity.
Drug Therapy
- In secondary prevention, recommends consideration of initiating therapy
simultaneously with lifestyle changes and during hospitalization for
major coronary events, if the LDL is 100
mg/dl.
Special Issues and Considerations:
- Metabolic Syndrome, as previously defined, has been recognized
in the guidelines for the first time since some triglyceride rich lipoproteins
(TGRL) are atherogenic. A way to calculate these TGRLs is provided:
non-HDL cholesterol (total cholesterol-HDL). The upper limits for normal
is considered to be 30 mg/dl higher than the LDL goals. Thus, non-HDL
cholesterol is a secondary target with LDL being the primary target.
In managing these patients, diet, weight loss and exercise are extremely
important.
- Post menopausal women. Hormone replacement therapy is no longer
recommended in women with CAD. Rather, statin therapy is the treatment
of choice.
- Elderly. Based on secondary prevention trials, there are no
longer any age limits for institution of LDL lowering therapy.
- Young Adults. An LDL 190
mg/dl, in the absence of other risk factors, is recommended for drug
therapy in men 20-35 years of age and women 20-45 years of age. LDL
levels in the 160-189 range are considered optional for therapy.
Most data show that insufficient numbers of patients with CAD are being
treated, and those that are being treated are often not treated in a sufficiently
aggressive manner. These guidelines confirm the desirability of aggressive
therapy and, in some instances, promote even more aggressive goals than
previously set. Regardless of new and emerging risk factors and the potential
benefit from treating them, the data are clear that LDL lowering therapy
does reduce risk and should be pursued aggressively.
References
1. Arch Int Med 148: 36, 1988
2. JAMA 269:3015, 1993
3. JAMA 285:2486, 2001
4. www.nhlbi.nih.gov/guidelines/cholesterol/profmats.htm
5. Circulation 97:1837, 1998
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