Thanks Graham for putting me in the spotlight!
Four standard drinks per week is most unlikely to produce a GGT of 132.
Either he is drinking more than he is willing to declare, or something else
is going on:
- hepatic enzyme induction, classically from anticonvulsants (presumably
not the case) or some anti-TB drugs (rifampicin comes to mind) but
conceivably from some herbal or folk remedy, or dietary constituent, which
I can only guess at (given the Middle Eastern background, but possible in
anyone nowadays)
- chronic hepatitis, perhaps improving slightly when he stops the four
drinks per week (an innocuous or even beneficial amount for most people but
said to be inadvisable in someone with hep B or C); but maybe the AST & ALT
would be higher in that case?
- obesity and/or hypertension and/or insulin resistance and/or NIDDM and/or
hepatic steatosis; all these are statistically associated with high GGT.
The BMI would probably need to be in the top quintile of the population to
produce a GGT this high (maybe above 30?).
- iron overload/high ferritin is also associated with increased GGT,
probably synergistically with alcohol in most cases; particularly with PCT,
maybe also in haemochromatosis but this is unlikely in someone with his
genetic background.
Four or five prospective epidemiological studies have shown that a high GGT
is associated with increased risk of death and of use of health-care
resources. Part of this risk is no doubt due to excessive alcohol
consumption but there is also an increased risk from cardiovascular causes,
probably via insulin resistance.
In practice I would suggest excluding the more worrying causes of high GGT
and suggesting lifestyle improvements if appropriate; physical exercise is
associated with improvement in GGT over the medium term. Since cutting out
alcohol has coincided with a reduction in GGT, maybe he should continue to
avoid it.
(Coffee consumption is also statistically associated with lower GGT but I
don't think anyone has investigated whether this is therapeutic.)
In passing, your reference ranges are lower than most people would supply
and I presume this is due to an aggressive approach to selection of a
reference population rather than a method giving low results. If there is a
method difference then the GGT is around 4 times the ULN and the value of
132 looks even worse -equivalent to about 200 in other people's terms.
John
John Whitfield
Clinical Biochemistry
Royal Prince Alfred Hospital
Sydney, Australia
Phone (+61) 2 9515 5246
Fax (+61) 2 9515 7931
-----Original Message-----
From: Graham Jones [SMTP:[log in to unmask]]
Sent: Wednesday, 26 July 2000 10:36
To: [log in to unmask]
Subject: alcohol and GGT
Dear colleagues,
I write concerning a patient identified as part of a collection for
reference intervals. In return for their blood, we returned their results
with a consultation if required.
One male in his 50s, middle eastern background, possibly carrying a few
kilograms (don't we all) turned up the following liver function test
abnormalitites:
GGT 132 U/L (reference interval <35 U/L), ALT 55 U/L (<30 U/L), AST 33 U/L
(<30), other LFTs with current reference intervals.
The only ingested agent which came to light on history was alcohol at about
4 standard drinks per week.
I suggested he abstain and we repeat the tests.
The repeat GGT after 2 weeks was 70 U/L and ALT was 43 U/L.
This is a least circumstantial evidence that alcohol may be a causative
factor in his LFT derangement.
My questions are as follows:
1. Can alcohol at this level (40 g/week) cause these LFT changes, and
2. If it can, does this indicate significant damage which should lead to
alcohol abstinence.
Thank you in advance for your assistance (John Whitfield especially may be
able to provide some light).
Graham
Graham Jones
Staff Specialist in Chemical Pathology
St Vincent's Hospital, Sydney, Australia
Ph: (02) 9361-2170 Fax (02) 9361-2489
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
|