I ran across this post at http://loraldiabetes.blogspot.com/  It ties in
with our BG discussions so I copied it below:


Monday, February 16, 2009


I
<http://loraldiabetes.blogspot.com/2009/02/i-ate-nothing-why-are-my-bgs-high
.html>  Ate Nothing! Why Are My BGs high? 


Most of us discover fairly quickly after we start testing after meals that
eating carbs leads to a rise in our blood glucose levels. That seems
logical, and it is, so managing those carbs and the resulting spikes becomes
a cornerstone of home treatment.

But pretty soon we also discover that logic has limitations. We go to bed at
night with good numbers and wake with high numbers. But we didn't eat in our
sleep. Or we make the mistake of thinking 'food = spike, fasting = no spike'
and find that after eating nothing for six hours we might be normal or even
high when we expected to be low.

It doesn't seem to make sense, does it? "I Ate Nothing! Why Are My BGs
high?".

I am no expert on this, but I am pretty good at looking things up and then
testing the things I read against my own results. My body, my science
experiment. So I checked this out a long time back when I first came across
the term "liver dump". Here is my rough version, based on the
http://themedicalbiochemistrypage.org/glycogen.html (or that I could
understand at my level:-) . This is the medical-speak version:

"Stores of readily available glucose to supply the tissues with an
oxidizable energy source are found principally in the liver, as glycogen.
Glycogen is a polymer of glucose residues linked by a-(1,4)- and
a-(1,6)-glycosidic bonds. A second major source of stored glucose is the
glycogen of skeletal muscle. However, muscle glycogen is not generally
available to other tissues, because muscle lacks the enzyme
glucose-6-phosphatase.
*snip*
The major site of daily glucose consumption (75%) is the brain via aerobic
pathways. Most of the remainder of is utilized by erythrocytes, skeletal
muscle, and heart muscle. The body obtains glucose either directly from the
diet or from amino acids and lactate via gluconeogenesis
<http://themedicalbiochemistrypage.org/gluconeogenesis.html> . Glucose
obtained from these two primary sources either remains soluble in the body
fluids or is stored in a polymeric form, glycogen. Glycogen is considered
the principal storage form of glucose and is found mainly in liver and
muscle, with kidney and intestines adding minor storage sites. With up to
10% of its weight as glycogen, the liver has the highest specific content of
any body tissue. Muscle has a much lower amount of glycogen per unit mass of
tissue, but since the total mass of muscle is so much greater than that of
liver, total glycogen stored in muscle is about twice that of liver. Stores
of glycogen in the liver are considered the main buffer of blood glucose
levels."

For the really detailed version click on the links.

Below I put that in words that I understand. I am no biochemist, so if any
experts are reading this please correct any errors I make or omissions from
over-simplification.

Liver Dumps.

We need glucose for energy. When we eat a meal it is usually a mix of
carbohydrates, protein and fats. Carbohydrates are an easily converted
source which quickly appear as glucose in our blood. We also, more slowly,
obtain glucose by gluconeogenesis
<http://themedicalbiochemistrypage.org/gluconeogenesis.html>  from protein
or even fats and also from the stored energy in our liver and other organs.

When we create more glucose than our immediate needs some is stored. Some is
stored as fat, especially if we have excess insulin floating around, and
some is converted to glycogen
<http://themedicalbiochemistrypage.org/glycogen.html> . Glycogen is stored
mainly in the liver and the muscles. The muscles are selfish because the
glycogen stored in the muscles can usually only be used for the muscles, but
the glycogen stored in the liver is our supply for any glucose needed by the
rest of the body. When the body needs it the right amount is automatically
released to the right places. As a result there is always a steady flow of
energy to meet a person's needs, regulated to demand, regardless of when or
what they eat.

At least, that is how it works in non-diabetics. It is the body's version of
a fuel tank. Unfortunately, for type 2s, the system can be flawed. Type 2s
on the internet use the term "liver dump" for the release of excessive
glycogen fr0m the liver to become blood glucose at times when it wasn't
really needed or wanted.

For example, one cause of the Dawn Phenomenon
<http://www.diabetic-talk.org/dp.htm>  (not working, see foot-note) is
thought to be the body sensing our need for energy when we are about to
wake, leading to excessive glycogen release until we eat and send the signal
to stop the release. That's why a breakfast soon after we wake is an
essential meal for many of us. Similarly, fasting, exercise or heavy
physical activity can lead to a liver dump if the body senses the reduction
in blood glucose levels and over-compensates with excessive glycogen
release.

Preventing liver dumps is complex and I know no general solution. For dawn
phenomenon the most common treatment is to eat a late night snack; but the
reports of successful snacks vary widely so it's best to perform your own
experiments until, hopefully, you find the one that works for you. A
minority never does, and others find that the only solution for them is
basal insulin.

For those who experience liver dumps after fasting the solution is easy.
Don't fast for long periods. Eat something every few hours, even if it is
only a small snack.

For those who get them during or after exercise, I have seen reports of
success from people who spread small carby snacks across the period of
exercise, including a snack before starting.

Sorry I can't be more specific with answers on this one, just suggestions.
Once again it's your body, your science experiment

Cheers, Alan, T2, Australia.

Everything in Moderation - Except Laughter

Note added 31 March 2009: The link to the "Dawn Phenomenon" is temporarily
inoperative. As an alternative you will find an excellent explanation for
that, and many other things, on the Misc.Health.Diabetes FAQs
<http://www.faqs.org/faqs/diabetes/faq/part2/> . Click on the link and
scroll down to "Why is my morning bg high? What are dawn phenomenon,
rebound, and Somogyi effect?". 

Posted by Alan