(Almost)
Everything You Need to Know About Statin Drugs
by
Maryann Napoli
Though
the first of the statins went on the market over 17 years
ago, they unofficially reached miracle drug status last
summer when these cholesterol-lowering medicines made the
front cover of Newsweek. The magazine's breathless coverage
started with the inevitable anecdote about a middle-aged
man who was unable to lower his total cholesterol level
of 290 through diet and exercise alone.
Six
months of trying, and his level dropped a mere 27 points,
so his doctor put him on “one of the class of powerful cholesterol-lowering
drugs,” Lipitor. “He knows he should try harder to eat right,”
continued the Newsweek article, “but he also knows he doesn't
have to worry about cholesterol as long as he takes that
little pill every day. 'It's better living through chemistry,'
he says. Or perhaps more to the point, longer living.”
Well,
that just about sums up the current rosy view of statins.
It is also indicative of the unrealistically optimistic,
one-sided information consumers get about these drugs from
their doctors, the media and drug industry advertising.
Too often, people get little more than this from their doctors:
“Your cholesterol is too high, take this drug.” Or, if pressed
for more information, a doctor might say: “Take this drug,
it will reduce your chances of dying from a heart attack.”
Statins
are intended as a lifelong treatment. Any drug taken by
a healthy person every day for the rest of his or her life
should be backed with clear evidence from carefully conducted
studies that the benefits outweigh the risks. Such studies
should have included people just like you, be they older
women whose only risk factor is high cholesterol or middle-aged
men with high cholesterol and several other risk factors
for heart disease.
A
Critical Look is Needed
This
issue of HealthFacts will address such questions as: Are
statins safe and effective for everyone? What exactly have
they been proven to do? Will they increase longevity, as
the Newsweek article implies? It will also describe a new
analysis of all statin studies, which contradicts the prevailing
belief that these drugs are of great preventive benefit
to most older people. You will learn that the case for statin
therapy is stronger for people with heart disease and/or
diabetes than it is for healthy people with high cholesterol
and another risk factor or two.
When
statins were first introduced, they were prescribed primarily
to people with heart disease. In time, they became an appropriate
prescription for all older people. Lest you think
that's an exaggeration, recall the news out of England in
the summer of 2003, when a respected team of researchers
proposed the “ polypill ” for all adults over the age of
55, with a statin as one of six chosen lifesaving components
(along with aspirin, folic acid, and three anti-hypertensive
drugs at half dose).
The
polypill might not have caught on yet, but the idea that
just about every middle-aged and older person is a candidate
for statin therapy certainly has. In fact, you needn't have
high cholesterol to get a prescription. And for older women,
statins have begun to replace postmenopausal hormones as
the drug of choice to prevent heart disease.
Advertised
Widely
One
can hardly make it through the TV evening news without viewing
at least one statin ad, usually conveying the idea that
diet and exercise are not enough to lower cholesterol in
most people. (True enough, but more on that later.) The
most egregious statin ad, however, is Pfizer's campaign
in Canada where, ironically, it is against the law to advertise
prescription drugs to consumers.
Pfizer
Canada gets around the law by not mentioning the name of
its drug (a familiar tactic used in the U.S. to circumvent
the mandated requirement of describing side effects). In
what is known as a “heart disease awareness” ad, Canadians
are encouraged to ask their doctors for a cholesterol test.
The ad shows the bare feet of a corpse on a morgue drawer
with a toe tag that reads: Male, age 42; cause of death:
heart attack. The ad's headline: “What would you rather
have, a cholesterol test or a final exam?”
Six
statin drugs are now available: atorvastatin (Lipitor),
fluvastatin (Lescol), lovastatin (Mevacor), pravastatin
(Pravachol), rosuvastatin (Crestor) and simvastatin (Zocor).
Altogether statins drive a $20 billion a year world-wide
market, with Lipitor No. 1-- of all prescription
drugs--in retail sales in the U.S. No head-to-head comparison
has ever been conducted to determine whether one is superior
to the others.
Statins
are widely regarded as safe, and perhaps the safest of all
cholesterol-lowering drugs, though no one has done a study
comparing them against their older counterparts. The acknowledged
side effects of statins include muscle pain and weakness,
suppression of the body's formation of Co-enzyme Q10 and,
rarely, a potentially fatal muscle-wasting disorder called
rhabdomyolysis. One statin, Baycol, has been withdrawn because
it was linked to 31 deaths from rhabdomyolysis. The other
statins still pose a rare risk for this disorder, especially
at doses of 80 mg/daily. Another rare side effect is peripheral
neuropathy, which is nerve damage that causes numbness or
tingling in the hands and feet. Chief among the unacknowledged
side effects are memory loss and other cognitive problems,
which have been reported anecdotally by people who were
not in clinical trials.
There
is a controversy among researchers over the very real possibility
that the benefit of statins has less to do with cholesterol
reduction than the drugs' other biochemical effects, most
notably anti-inflammatory properties. Atherosclerosis is
thought to be due to an inflammatory response to arterial
injury--an injury caused by high blood pressure, smoking
or other risk factors.
Cholesterol
as a Disease:
To
understand today's obsession with cholesterol, it helps
to have a little background regarding this particular risk
factor and how it came to be treated as if it were a disease.
High blood levels of cholesterol emerged as a risk factor
for heart disease in the Framingham Heart Study, whose results
have been misrepresented, according to some researchers.
Begun in 1948, it followed 5,000 healthy men and women living
in Framingham, Massachusetts, to determine which factors
distinguished those who eventually suffered a heart attack.
Cholesterol
was identified as one, but only one of 240 risk factors
that included short stature, male baldness, creased ear
lobes, and being married to a highly educated woman. Research
focused on cholesterol because it is a modifiable
risk factor (translation: drug industry opportunity). Though
the Framingham Study found a strong association between
blood levels of cholesterol and heart disease only in
young and middle-aged men, the entire population was, in
time, instructed to fear this particular risk factor.
Contrary
to conventional medical wisdom, the Framingham study did
not find that a high-fat diet doomed people to a heart attack.
A subgroup of Framingham participants was assessed for their
intake of saturated fats, dietary cholesterol and overall
calories. None had any effect on the development of heart
disease.
The
idea that a low-fat diet prevents heart disease lives on,
despite a 2001 review of all relevant clinical trials. The
combined results showed that reducing or modifying dietary
fat intake had no effect on heart disease mortality or total
mortality (Hooper et al. British Medical Journal, 3/31/01).
However, modest reductions in non-fatal cardiovascular “events”
(e.g., strokes, heart attacks) were shown in the few trials
in which the participants remained on the diet for more
than two years.
Several
books have been written about the overrated importance of
cholesterol (both dietary and blood levels) in the development
of heart disease, most notably Heart Failure (1989)
by Thomas J. Moore, The Cholesterol Myths (2000)
by Uffe Ravnskov , MD, PhD, and Tales from the Other
Drug Wars (1999: Chapter on Lipid-Lowering Drugs by
Isabelle Savoie www.chspr.ubc.ca/misc/drugwars2.pdf)
Such skeptics are usually fond of pointing out that half
of all heart attacks occur in people who have normal cholesterol
levels.
Lifestyle
Changes Often have Small Effect
Once
a person's blood test shows high cholesterol, a low-fat
diet is recommended, along with the admonition to get regular
exercise. Most people will find that these two lifestyle
changes bring only minimal reductions in cholesterol, making
statin therapy the inevitable next step.
Given
the emphasis on cholesterol “numbers,” it is easy to lose
sight of the fact that the ultimate goal of drug therapy
is not to lower cholesterol but to reduce the odds of dying
of a heart attack or stroke. A pharmaceutical company seeking
approval from the FDA, however, need only prove its drug
can lower cholesterol. The more important, long-term studies
are initiated many years later.
When
researchers began conducting clinical trials to prove that
lowering cholesterol will prevent cardiac deaths, they ran
into some major snags over the course of several decades.
Despite millions of dollars spent on clinical trials, researchers
simply could not prove that lowering people's cholesterol
had any effect on life expectancy. Whether the study participants
lowered their cholesterol with diet, exercise, smoking cessation,
and/or drugs, the heart disease death rate went down but
the over-all death rate, that is, the death rate from all
causes, went up. In other words, their total death rate
was no different from that of the people who did not lower
their cholesterol.
Statins
are Different...or are They?
Proof
that statin drugs can benefit people without heart disease
comes from five clinical trials in which the participants
had been randomly assigned to take a statin or a placebo
daily. Altogether about 40,000 healthy but high-risk people,
aged 55 to 82 years, participated in these clinical trials,
with the statin doses ranging from 10 mg to 40 mg a day.
Participants were primarily males with high cholesterol
and other risk factors, such as smoking and angina (chest
pain caused by constrictions in the coronary arteries).
In one trial, the men and women had either normal or borderline
levels of cholesterol. Several reviews of the five clinical
trials came to the conclusion that statins can reduce the
rate of non-fatal heart attacks and strokes. The drugs also
reduce cardiovascular mortality, but they did not reduce
all-overall mortality.
Conveying
the Benefit to the Public:
Interestingly,
the Newsweek article devoted only one sentence to the critical
question of what has been proven regarding statins. Without
further explanation, the article says a large study “showed
that cholesterol-lowering drugs reduced the risk of heart
attack and stroke by at least one quarter for those at highest
risk.” While this is roughly accurate, it appears more impressive
than the reality. The one-quarter reduction refers to the
difference in the rate of heart attack between the study
participants taking statins and those on the placebo.
What
makes the statistic misleading is the fact that healthy
people--even those with high cholesterol--have a low risk
of having a heart attack to begin with. And reducing their
odds of having a heart attack by one-fourth simply means
that 3% of the statin-treated study participants had a heart
attack or stroke, as compared to 4% of the untreated participants
(the placebo group). Or put another way: There were 1% fewer
statin-treated people had heart attacks. The studies lasted
only about five years so these statistics apply to taking
the drug only for that length of time. (See Web sites listed
at the end of this article for help in understanding risk
assessment.)
It
is not unusual for reviewers to look at the same trials
and come to different conclusions about what has been proven.
This is what happened when a Canadian team of researchers
conducted its own review of the five statin trials. This
new analysis took issue with the generally agreed upon conclusion
that these five trials proved that the benefit of statins
far outweigh the risks.
The
New Analysis:
The
analysis of the five trials was conducted by a team of researchers
at the University of British Columbia led by James M. Wright,
PhD, who came to the alarming conclusion that statins harm
as many people as they help. True, the combined results
of the five trials did, in fact, show a lower rate of non-fatal
heart attack and stroke. However, once serious adverse events*
were taken into account, the results were not so positive.
The statin users did have 1.4% lower rate of heart attack
within the next five years, compared with untreated people,
but that small benefit was offset by a 1.8% rate of serious
adverse events associated with the drug.
Dr.
Wright and colleagues might be the first reviewers to step
back and look at the big picture--assessing the serious
risks as well as the benefits of statins. Only two of the
five trials reported serious adverse events. “Based on the
two trials, we are suspicious that some serious adverse
events are being increased by statins and that this appears
to be canceling the benefit of the reduction in heart attacks
and strokes,” Dr. Wright wrote in an e-mail interview. The
new analysis was published in the April-June 2003 issue
of Therapeutics Initiative, an evidence-based drug therapy
newsletter (“Do Statins Have a Role in Primary Prevention?”
Available free at www.ti.ubc.ca).
Dr.
Wright is associated with the Cochrane Collaboration, an
international network of experts who conduct systematic
reviews of the supporting evidence for drugs and other medical,
surgical or behavioral interventions. In a move that distinguishes
many Cochrane reviewers, Dr. Wright and his colleagues at
the University of British Columbia contacted the authors
of the three trials that did not publish the number of serious
adverse events suffered by their study participants. The
reviewers have yet to receive the requested data.
Yet
to be Proved for Women:
In
the e-mail interview, Dr. Wright was asked about statins'
proven benefit specifically to women--something omitted
from the analysis as it appeared in Therapeutics Initiative.
To answer this question, Dr. Wright did a separate analysis
of women who participated in four of the five primary prevention
trials, emphasizing that they made up only 28% of all the
study participants. “Combined results of all trials do not
support the use of statins by women without heart disease,”
concluded Dr. Wright. This is explained by the fact that
women were not only underrepresented in the trials, but
also, as a group, have a very low risk of having a heart
attack in a five-year period.
The
University of British Columbia researchers are not the first
to notice that the benefit of statin therapy to women remains
an open question. High cholesterol has never been proven
to be an important risk factor for women. At every stage
of life, women tend to have higher blood levels of cholesterol
than men of the same age; yet they are about 15 years older
then men at the age of a first heart attack.
Statins
have begun to replace postmenopausal hormones as the all-purpose
drug to prescribe to healthy older women whose only risk
factor is high cholesterol. It is noteworthy that many of
the additional benefits claimed for statins--beyond cholesterol
reduction--are similar to those made prematurely for estrogen.
For example, some women are told that statins will also
reduce their risk of Alzheimer's disease and osteoporosis.
The latter has been disproved, and the former comes only
from preliminary studies.
More
cases of breast cancer have shown up among statin users
in three trials. In all three, the finding was described
as “not statistically significant.” One trial involving
people with heart disease who either took a placebo or 40
mg of Pravachol daily found that breast cancer developed
in 12 out of 286 women taking the drug, compared to one
out of 290 on the placebo.
People
over 70
Whether
high cholesterol is a problem for elderly people has been
the subject of a long-running controversy. So has the question
of whether cholesterol-lowering drugs can provide any benefit
to this age group. The controversy was theoretically settled
by a large multi-center European trial published in 2002
when The Lancet published a major trial, known by the acronym
PROSPER. It showed that statins lowered the incidence of
coronary events but had no effect on longevity. The PROSPER
trial, however, lasted only three years.
The
participants, aged 70-82 years either had heart disease
(44%) or had risk factors for heart disease (56%). The PROSPER
results showed an ominous increase in the frequency of new
cancer diagnoses in the people taking Pravachol, which was
dismissed as a “chance finding” by the authors. In response
to the PROSPER trial three of five letters to the editor
of The Lancet took issue with the description of “chance
finding.” One letter noted that the cancer incidence over
three years was 6.8% in the placebo group and 8.5% in the
people taking Pravachol.
Another
letter to the editor expressed concern that the PROSPER
will encourage the use of statins in elderly people: “Surely
one relevant statistic is that by treating 5,804 high-risk
patients with pravastatin [Pravachol] or a placebo, the
overall death rate [sic] was reduced from 306 to 298 over
three years. This was achieved at what cost to the perception
of good health, comfort, or anxiety among the participants?”
wrote Peter J. Little of New Zealand (Lancet, 2/1/03). Such
critics recently gained support from the new analysis by
the University of British Columbia researchers who concluded
that the cardiovascular benefit shown in the PROSPER trial
was offset by serious risks.
Reaction
to the New Analysis
The
new analysis met with criticism from cardiologists in Canada,
but it has been largely ignored in the U.S. The criticism
centers on the fact that the University of British Columbia
research team came to entirely different conclusions about
statins than virtually all other medical organizations that
have reviewed the same studies. In a recent article for
the Toronto Globe & Mail, Dr. Ruth McPherson dismissed
the research team because it did not include specialists
in cholesterol metabolism and treatment. Furthermore, the
findings were published in Therapeutics Initiative (TI)
which “does not have the status of a peer-reviewed journal.”
TI,
which is based at the University of British Columbia, is
a newsletter that is peer-reviewed, according to its Web
site, by family physicians, specialists, academic researchers,
pharmacologists, pharmacists and epidemiologists. TI is
funded by the Canadian Government to help doctors make evidence-based
treatment choices. The average practicing physician does
not have the time to pick through each statin trial to determine,
say, whether women are represented in large enough numbers,
or whether the odds of being harmed by a drug are equal
to its odds of a benefit.
People
with Heart Disease or Diabetes
Statins
clearly benefit diabetics and people with heart disease
who want to avoid a heart attack or stroke, as well as those
who have already suffered one and want to prevent another.
Such people are more likely to benefit from statin therapy
because their odds of having a heart attack or stroke are
so high. Pravachol and Zocor are the best assessed statins
for people who have
diabetes and/or heart disease. Altogether more than 35,000
people who fit this profile took part in trials that compared
a statin with a placebo.
The
most recently published large trial was conducted in the
United Kingdom; 25% of the participants were women and 46%
were over age 65 years. All had been randomly assigned to
take Zocor or a placebo for five years. Results showed that
the participants who took Zocor decreased their odds of
overall mortality by 1.8% in the next five years, compared
to those who were untreated (placebo group). Coronary deaths
were reduced by 1.2% among statin users within five years.
The reductions were higher for people who have already had
a heart attack or angina and for diabetics. Contrary to
expectations, Zocor showed no beneficial effect on fractures
or dementia. As for the cancer-related concerns, Zocor did
not alter the overall incidence of cancer ( Prescrire International,
8/03). No separate analysis has been done for women.
As
for the importance of reducing fat intake, this particular
lifestyle change has more relevance to people who have heart
disease than it does to healthy people. Combined results
of seven clinical trials involving participants with heart
disease showed that dietary changes provided a 6.6% lower
incidence of heart attacks and/or cardiovascular deaths
than those who did not reduce fat intake.
Web
Sites for Understanding Risk
www.besttreatments.org/risk
This Web site in the United Kingdom helps you understand
percentages as in: Take aspirin daily because studies show
your risk of heart attack will be halved. Here's another
way to present the same thing: 2% of people like you will
have a heart attack in the next ten years, compared to 1%
of those who took aspirin daily. Examples, such as this
one, are given to help you question your doctor whenever
percentages are quoted in relation to a proposed medical
treatment. To understand what “halve your risk of heart
attack” means, one would have to know his or her risk of
having a heart attack without taking the drug.
www.icru.no/hippo/cholesterol
As the above example shows, people can make different decisions
according to how the information is presented. This Web
site in Norway consists of a quiz developed by researchers
who are exploring different ways to communicate risk information
to consumers. You can contribute (and become better informed
about risk assessment) by taking the quiz which involves
the decision whether or not to take a cholesterol-lowering
drug.
http://hin.nhlbi.nih.gov/atpiii/calculator.asp
The U.S. National Cholesterol Education Program offers this
quick quiz for assessing your odds of having a heart attack
in the next ten years. Unfortunately, the calculation is
too brief, leaving out such important cardiovascular risk
factors as diabetes and family history of early heart attacks.
--
Maryann
Napoli is the associate director of the Center for Medical
Consumers in New York City.
November
2003.
*Serious
adverse events includes “any medical occurrence that results
in death, is life-threatening, requires hospitalization
or prolongation of hospitalization, or results in persistent
or significant liability.”