How Low Should Your LDL Cholesterol Be?
New guidelines mean more people should
be taking medications.
If your doctor has recently become more aggressive about lowering
your low-density lipoprotein (LDL, or “bad”) cholesterol—for
example, setting a lower target goal and increasing your statin
dosage—it’s likely that the adjustment was inspired
by new guidelines.
The guidelines call for lower LDL cholesterol levels for people
at high or moderately high risk for a heart attack. They were
published in the journal Circulation in 2004 and are endorsed
by the American Heart Association, the American College of Cardiology,
and the National Heart, Lung, and Blood Institute. An expert
panel based their recommendations on five recent clinical trials
showing that more aggressive lipid-lowering therapy is more effective
than the current moderate therapy recommended in the 2001 U.S.
National Cholesterol Education Program (NCEP) guidelines.
The most recent of the five trials—the Pravastatin or
Atorvastatin Evaluation and Infection Therapy (PROVE-IT) study— was
published in The New England Journal of Medicine in 2004.
It measured the relative impact of different treatment strategies
on clinical outcomes such as heart attack and death. The trial
compared these strategies in more than 4,000 patients who had
been hospitalized for acute coronary syndrome (a recent heart
attack or unstable angina). The participants were randomly assigned
to receive either standard or intensive lipid-lowering therapy.
The PROVE-IT trial reported that reducing LDL cholesterol levels
below currently recommended targets clearly benefited patients
with acute coronary syndrome. Standard therapy lowered LDL cholesterol
levels to an average of 95 mg/dL, while intensive therapy reduced
LDL cholesterol to an average of 62 mg/dL.
The benefits of high-dose statin therapy became apparent within
a few months. After a follow-up of two years, patients on intensive
therapy had experienced a 16% lower risk of unstable angina,
heart attack, and bypass surgery than those on standard therapy.
In addition, the death rate from all causes after two years was
almost 30% lower in the group receiving high-dose statin therapy.
The findings and new recommendations apply only to secondary
prevention—that is, preventing heart attacks and, possibly,
strokes in people who already have coronary heart disease (CHD).
But many experts expect that future research may show that aggressive
LDL cholesterol lowering is also effective for primary prevention—that
is, improving outcomes in people without known CHD.
The positive results of the PROVE-IT trial and the other four
studies examined by the expert panel strongly suggest that people
who’ve already had a heart attack or other cardiovascular
event—who are, therefore, at high risk for future heart
attacks and death—can greatly benefit from intensive lipid-lowering
Your New Goals
If you are at low risk for a heart attack, your LDL cholesterol
target goal is still the same—160 mg/dL or lower. Similarly,
if you are at moderate risk, your LDL cholesterol target is still
130 mg/dL, and drug treatment may be considered if LDL cholesterol
levels are 160 mg/dL or more.
People at higher risk for a heart attack, however, have new
goals. Those at moderately high risk may want to lower their
LDL cholesterol to less than 100 mg/dL (rather than 130 mg/dL)
and to start using medication when LDL cholesterol is between
100 and 129 mg/dL. People at high risk should consider lowering
their LDL cholesterol to less than 70 mg/dL (the previous goal
was 100 mg/dL) and to begin drug treatment even if LDL cholesterol
levels are below 100 mg/dL.
What To Do
First determine how many of the following risk factors you have:
• cigarette smoking;
• high blood pressure (140/90 mm Hg or higher) or taking blood pressure-lowering
• HDL cholesterol below 40 mg/dL;
• family history of a premature CHD event (under 55 in men, under 65 in
women) in a first-degree relative (mother, father, or sibling); and
• older age (45 or over in men, 55 or over in women).
Next, calculate your
10-year risk of a heart attack. If you do not have access to
the Internet, ask your doctor what your risk is.
Then, consult the table above to determine your LDL goal and
at what LDL level you should start taking medication. According
to the new guidelines, statin therapy should be intense enough
to achieve at least a 30% to 40% reduction in LDL cholesterol
levels. And don’t forget that lifestyle changes—such
as quitting smoking, eating a healthy diet, and exercising—can
help make your medication more effective.
Adapted from Circulation, July 13, 2004, p. 236.