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The Straits Times Asia One
MARCH 20, 2004 Our Columnist Healthy ticker but taking
statin to be safe? You may be sorry By Andy Ho
HAVE you had your statin this morning? That's a pill you
take if you have a cholesterol level so high that dieting
won't bring it down. Millions around the world are popping
these pills, which are billion-dollar best-sellers for their
manufacturers.
Excess cholesterol causes gunk to build up in the walls of
arteries, narrowing the bore, thus blocking them. Blockages
may result in heart attacks or strokes, while statins lower
cholesterol levels, thus preventing such blockages.
So why not have people - even those with normal cholesterol
levels - take statins for life? This weekend, a doctor will
propose just that at a conference at the Ritz-Carlton
entitled Controversies And Recent Advances In Cardiovascular
Medicine. And he won't lack support.
But is this idea sound?
Up until now, it has been accepted wisdom that people with
too much bad cholesterol (low-density lipoprotein or LDL)
should receive statins - unless they also have high levels
of good cholesterol (high-density lipoprotein or HDL). Both
LDL and HDL are actually proteins that transport
cholesterol, albeit in opposite directions: LDL trucks
cholesterol to heart and brain arteries, where it is laid
down to form gunk. HDL shovels cholesterol away from these
arteries, ferrying the artery clogger to the liver for
processing.
However, recent studies, like one published in the Journal
Of The American Medical Association last week, claim that
your good cholesterol may be of a malfunctioning variety.
Depending on your genes, your HDL may not actually be
protecting your heart. But we can't tell for sure since the
blood test gives you only your total cholesterol level, not
its functionality. Just to be safe, proponents reason, why
not take statins even if you have lots of so-called 'good
cholesterol'?
But the track record of statins gives cause for pause.
Introduced in 1987, they are the most potent of cholesterol-
lowering agents - but hardly the safest. For example, a
particular statin called Baycol (cerivastatin) was withdrawn
in 2001 after apparently causing 1,100 cases of muscle
weakness and at least 100 fatalities.
Though statins, as a class of drugs, have been around for
more than 16 years, no study of any particular statin
exceeds four years. It is fair to say, therefore, that what
its side effects might be after you have been popping one
for 20 years make for a huge unknown. What is already well
known but widely understated is that statin-poppers could
develop muscle and memory problems.
First, statins carry a small but definite risk of causing
potentially fatal muscle problems as they can cause a toxic
reaction leading to what is called rhabdomyolysis. The
patient develops severe muscle aches, soreness or weakness -
and brown urine, perhaps the most tell-tale symptom.
Initially described with crush injuries suffered in the
World War II bombing blitz of London, rhabdomyolysis means
that muscles are disintegrating and pouring out toxic muscle
cell components into the bloodstream. These toxic products
then sneak through the meshwork of kidney capillaries to
clog up the fine urine-forming tubes. The end result is
kidney failure.
Rhabdomyolysis, which accounted for all the Baycol deaths,
may be caused by any statin currently on the market. The
risk: one death for every million of statin prescriptions.
So if you are on one and have some muscle pain or weakness
for no obvious reason, you should not let your doctor tell
you to take an aspirin and call him in the morning.
There is a second reason for doctors to take their patients'
complaints of vague pains seriously: Statins may also cause
cognitive problems.
It is now known that lowered cholesterol levels tend to be
associated with low serotonin levels, the chemical in the
brain that modulates mood, emotion, sleep and appetite. One
particular side effect that is attracting attention is
aggressive or violent behaviour in some when their
cholesterol levels nosedive.
While it is true that published statin studies don't even
hint at such a link, it is equally true they were not
designed to elucidate such a connection. A random, double-
blind trial (which prevents doctor and patient bias) now
under way at the University of California in San Diego will
help sort this out. It was reported last month in the
journal Archives Of Internal Medicine and the results are
due out later this year.
Statins may cause other side effects as well, such as
raising liver enzymes, the significance of which are
unclear.
So, should healthy people with normal cholesterol levels
take statins preventively as proponents suggest?
Probably not, if some University of British Columbia
analyses are anything to go by. Pooling data from seven best
statin trials carried out on people with high cholesterol
and coronary disease, the Canadian investigators found that
(secondary) preventive usage of statins did stave off a
second catastrophic event and reduced fatality rates.
In parallel analyses of five best statin trials carried out
on people with high cholesterol but no coronary disease,
they found that (primary) preventive usage was quite futile.
They reported in Therapeutic Letter last September that only
one in 70 such people put on statins are saved from a heart
attack or stroke. Even then, fatality rates are not reduced.
Extrapolating, it makes sense that if your cholesterol
levels have always been normal and your ticker is healthy,
taking statins preventively would be anything but judicious.
Except for drug firms.
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