Date: Sun, 16 Nov 2003 00:56:49 -0500
From: "Earl Dunbar" <edunbar@xxxxxxxxxxxxxxxx>
Subject: Re: [ [OT] pills,
Diet doesn't always work; some cholesterol problems are of genetic origin.=
While diet and exercise can help, levels can still be at high enough=
levels to be dangerous and require other strategies. That's what they=
told me after my angiogram.
Earl
Earl,
That's exactly what I was hired to develop that test for. This is
usually familial (or inherited) hyperhcholesterolemia (FH). You're
right, some people have a mutation in their low density lipoprotein
receptor that affects the expression of the receptor on the liver
cell. It is what is known as an autosomal dominant trait, meaning
you only have to have one mutation on one chromosome to be affected.
This receptor clears LDL from the blood. If you have a mutation on
one chromosome, you are what is referred to as heterozygous for FH.
What this means is that these folks make 1/2 the normal amt. of LDL
receptor on their liver cells, and hence, have poor clearance of LDL
from the blood. Therefore, their LDL levels are always high, and
there is nothing they can do about it as a result of diet or
exercise. These folks mandatorily need the statin drugs to lower
their LDL. What the statin drugs to is upregulate the expression of
their other, normal LDL receptor through a metabolic trick, as it
were, and thus these folks get close to normal clearance of LDL.
There are side affects because of the metabolic tricks, however, and
they can sometimes affect the liver. This is why people with liver
disease or dysfunction should not take statin type drugs. FH is
actually fairly common, the heterozygous mutation occuring roughly
in 1:500 individuals. It is 8 X more common that cystic fibrosis, for
example. What I did was to develop a genetic test that would identify
the causative mutations for FH, so you could segregate folks that
have high LDL cholesterol into two groups: those can control it
through diet and exercise, and those that can't, and have to be put
on statins to greatly reduce their risk of heart attack.
-Stephen.
--
2001 CBR600F4i - Fantastic!
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