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Type I Diabetes
There are a dozen or so different types of diabetes. However, type I and II are the
important ones, because they are the most prevalent (affecting the population in the highest
frequencies). Of types I and II, type II diabetes affects a greater number of
individuals.
Type II diabetes has other names, as we can see below.
adult onset diabetes
non-insulin-dependant diabetes (abbreviated IDD)
These names refer to type II diabetes and some of the names have evolved
as descriptive terms.
In common with Type I diabetes, Type II diabetes is also a disorder or carbohydrate
(sugar) metabolism.
When we consume sugars, they are normally absorbed through the intestines, and
carried into the blood. Once sugars (eg., glucose) are in the blood, they are transported
and stored in the liver, and muscles for later use. Some of the glucose is immediately
used as fuel. For example, the primary fuel for the brain is glucose, and without it,
we would lapse into unconsciousness within minutes. Therefore, we can see how important
glucose is and thuat there must be a constant level maintained in our blood at all times,
even when we haven't eaten much.
The levels of sugar in our blood are controlled by a few hormones.
Insulin is
the hormone responsible for storing sugars when we have just consumed a large
sugar (carbohydrate)-containing meal. Insulin prompts the sugars to leave the
blood and become stored primarily in the muscle and liver. Of course, the
level of insulin secreted is also controlled by the amount of sugar we consume. If
too much insulin was secreted by the pancreas, then too much sugar would be removed
from the blood and thus, blood sugar levels would fall to dangerously low levels.
This of course, is dangerous since the brain requires specific blood glucose levels
to supply it with energy. Therefore, we can see that blood sugar levels must
be carefully maintained. This is another example of
homeostasis.
In life,
many disease states develop from either too much or too little of something and
diabetes is no exception. In type I diabetes, there is an insufficient supply of
insulin. As we discussed, insulin is needed to maintain storage of glucose.
Therefore, if we do not make enough insulin for any reason, sugar levels will not
be able to be properly maintained. When this occurs, sugars cannot be effectively
removed from the blood, and accumulate. This is detrimental, because increased amounts
of sugars in the blood can cause problems for the walls of blood vessels in a
fashion similar to cholesterol Sugars can stick to the walls of blood vessels,
and hence, damage organs over time. Excess sugars can also bond to cholesterol and
"cross-link" it to the wall of a blood vessel, contributing to the artery clogging
process we know as atherosclerosis.
"How is type II diabetes different than type I?"
Insulin is produced in a small organ called the pancreas. The pancreas
is seated adjacent to the stomach and is the size of a "small strip of
steak". Insulin as well as other hormones are produced in the pancreas.
Wnen needed (eg., after a meal),
the pancreas liberates insulin, which functions is causing various tissues of the
body to store and metabolize sugar. We read about type I diabetes and how
destruction of the pancreas leads to a deficiency in insulin production. In
type II diabetes, this is not the case. The ihsulin levels are normal, or even
higher than normal. The pancreas has not been damaged in type II diabetes. So, it
is logical that insulin production remains normal. So, how are blood sugar levels
affected in type II diabetes when insulin production is normal?
Although the type II diabetic produces sufficient amounts of insulin, it does
not have an appropriate effect on the target tissues. The insulin is normal, and
has not been altered. However, the body develops a resistance to the insulin, so
that it is no longer as effective as it was before hand. The development of resistance
is caused by obesity. The increased amounts of lipids in the body causes the insulin
to have a decreased affect. The encouraging part of this condition, is that it is
reversible. In other words, upon decreasing weight, the insulin resistance also decreases.
What is the normal level of blood sugar?
The normal level of glucose in the blood is between 3 and 6 millimoles per litre (Well,
over the last few years, the value has been changed from 6 to 8, probably due to
reflections on western diets).
This means for each litre of blood, the average person has this much glucose in it.
When the level of glucose rises aboue the norm, we call it hyperglycaemia (huperglyemia).
Hyper means "greater than", and simply tells us that the person has a greater than
normal amount of sugar in the blood. If a person take too much insulin accidently,
they can cause too much sugar to leave the blood, and this is called hypoglycaemia
(hypoglycemia). Hypo simply means "less than". Many people naturally suffer from hypoglycaemia,
or low blood sugar as well. When their blood sugar levels fall, they
can develop symptoms of hypoglycaemia, such as irritibility, depression,
increased heart rate, weakness, sleepiness, and sweating.
For many of these people, simply cosuming some sugar or a light carbohydrate-
containing snack will correct the hypoglycaemia. However, clinical investigations
are always recommended, in the case of other possible metabolic disorders.
Diabetes
Type I Diabetes
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