Low carb for doctors: Baseline tests and screening
In the ninth part of our low carb for doctors series, Dr. Unwin discusses good measurements for feedback to patients. This can include getting a baseline weight, …
So thinking about feedback
for patients and also safety
is a good idea to chat about
what we're going to measure
So basic things first.
I've already talked
about getting a baseline weight.
For me that is absolutely fundamental.
But I also add to that
because I find it particularly affected
by the low-carb diet in a flattering way.
So this is great feedback for people when
they find their waist is getting smaller.
And some of my best ever graphs
have been what I call low-carb liposuction,
where some of the waist
shrinks down so much.
So those are the first simple ones.
And then I'd add to that blood pressure.
And this is because you will very likely find
if patients lose weight
that blood pressure is going to improve.
That's feedback but also is
an element of safety here,
because if they're on
then you may be going to make
some changes for your patients.
It's a good idea to tell them in advance
and explain why you're measuring
the blood pressure.
It's an opportunity also to bring up
the idea of perhaps some
home monitoring of blood pressure.
Patients quite like to do that.
And then they can chart
their own improvements
and many of my patients have done that.
Is good feedback, is good safety too.
Also going along with that
would be the idea of blood sugars.
Now you can monitor that
with a blood sugar meter.
As well, many of my patients
have their own blood sugar meters.
Or we can be more sophisticated,
of course we're all now
using hemoglobin A1c.
A quick word about hemoglobin A1c.
It's useful to explain to patients
that this is a blood test
which gives me an idea of how sugary
you have been in the preceding 2 to 3 months.
And so it gives us a really good idea
of how you're doing.
I find a lot of patients
are being refused blood tests
more often than once a year
or twice a year.
I think this is a shame.
If you're going to do a hemoglobin A1c
you'll often find a significant drop
after only two months.
And that early feedback is
so valuable for the patients.
So personally I'm getting
a baseline hemoglobin A1c
and then I'm going to be repeating
that blood test after two months,
because it gives me an idea
of how they're doing.
For me most of the patients
I'm doing blood tests
after two months of starting low-carb
because I want to know how they're doing.
Other blood tests.
I like to monitor liver function.
Again this is an opportunity
for positive feedback,
because you'll find
particularly the gamma GT results
and other of the liver function
will improve significantly.
Gamma GT is particularly interesting…
I always thought
that was due to alcohol.
And actually the results
I get with low-carb,
the gamma GT results are improving
by about 35% in the first year.
Many of those are patients who previously
I told off thinking they were drinking
and I've heard they weren't…
it seems to be linked for so many people
to carbohydrate intake.
That brings me on I suppose to lipids.
I would get a fasting lipid profile
to start with
and then I'm going to be doing that
again after two months.
I also do thyroid function.
It's interesting the TSH particularly
seems to improve in the first year.
I haven't seen this written up yet,
maybe I'll be the one to do it,
but certainly the TSH seem to be improving.
The other thing I would say is
do a full blood count as well
because you can't really interpret
what the full blood count is.
I'll illustrate that, I had a case recently
of a seemingly wonderful hemoglobin A1c,
a really low result.
And that was actually because of anemia.
So somebody with anemia
will have a low hemoglobin A1c,
and it isn't good news.
So occasionally I've come across
what looks like a really good hemoglobin A1c,
but actually the patient
has maybe colorectal carcinoma,
they are bleeding, they are anemic.
So you can't really do hemoglobin A1c
in my opinion in isolation.
You should be doing
the full blood count as well to check.
One thing to look out for
while you're measuring,
if somebody is losing weight
and hemoglobin A1c isn't improving,
you really need to ask why is that.
Because it could be that you've missed a
pancreatic carcinoma something like that.
So that pattern of weight loss
without an improvement in hemoglobin A1c
should be a cause of interest
and you need to go into that a bit more.
Moving on now into record keeping.
I think is really useful to build up
a file of evidence of what we're doing.
So in this practice for four and half years
now patients were serious about this,
we actually consent them
to sharing their anonymized data.
So that means I have a database
of a cohort now about 150
or 160 patients over the time
that I can share with other people
showing evidence of what we're doing.
So that's worth bearing in mind.
The best way to keep the database
is something like an Excel spreadsheet
so that you can keep updating it.
And for any of you that get interested
later on in publication,
that sort of data is exactly
what you need to write a paper.
So for me the journey went all the way
from keeping data to publication.
An exciting journey.
So it is really worthwhile both personally
and professionally keeping those records,
on top of which they form
a really useful source
of positive feedback for your patients.
So I mentioned keeping records
on an Excel spreadsheet.
And to illustrate my point I've got my own
here that I'd like to share with you.
This is useful really
because I can show you
what sort of average results
I've been getting over the last few years.
So if we begin just with looking
here at weight,
so my average patient who started off
weighing about 95 kg
and then the average result
is they weigh about 86.
So they're losing about 9 kg on average.
Of course, many of the patients
have lost more than that, many of them have lost less.
Moving over I mentioned
liver function test.
A particular fascination for
me is the gamma GT results.
You'll see we're beginning there
with an average result of 84
and that's dropping down to 45,
which is a very significant improvement.
Of course for many of you
you're looking at type 2 diabetes
and now we've got the average results
for the hemoglobin A1c.
Now if you take pre-diabetes
and also diabetes and lump them together
we're getting an average hemoglobin A1c
starting at 59 and ending up at 44.
So that's a reduction
in 15.4 mM per mole.
Just stepping back a little,
if you look at the subgroup
who actually have type 2 diabetes,
there is also rather more impressive
where we're beginning
with an average hemoglobin A1c of 68
and ending up with an average
hemoglobin A1c of 47.
Moving on we talked about lipids.
Interestingly again looking at my sheet
we get a slight drop
in the serum cholesterol on average.
So you'll see it starts off
on average 5.3, will end up at 4.9.
There's not a big drop,
but it is actually a significant one.
triglycerides are even more dramatic.
This is of course linked more closely in
with carbohydrate metabolism.
So it's not a surprise that the triglyceride
here is dropping from 2.3 to 1.5.
So triglycerides improve
by about a third.
The HDL cholesterol on average
is improving as you see there.
So it starts lower at 1.2
and it's going up,
because of course we like
hemoglobin A1c's [correction: HDL] to go up.
So we've nearly finished now,
just a final point on of blood pressure…
We measure lots of blood pressures,
again with weight loss we're getting
the systolic's dropping by about 9 mmHg
and the diastolic here
is dropping on average
by about 7 mmHg.
And bear in mind these results
alongside quite a lot of de-prescribing
of drugs for hypertension
and also de-prescribing
for lots of drugs for diabetes.
So we're getting better results
with fewer drugs.
So that's my Excel spreadsheet.
So just to summarize, we've been looking
at what you might measure
and that would be weight,
blood pressure, lots of blood tests.
What you're hoping to see is
results as I've just shown you,
which are really great
improvements in weight,
improvement in blood pressure,
improving liver function,
dropping hemoglobin A1c
and some improving lipids.