  
|  |
|
| Hypoglycaemia (low blood glucose) in non-diabetic people |
|
|
Reviewed by Dr Patrick Davey, cardiologist
|
What is hypoglycaemia (low blood glucose)?
Hypoglycaemia or low blood glucose is a condition in which the
level of glucose (sugar) in the blood, drops below a certain point (about
2.5mmol/l). The condition manifests itself by a number of symptoms that usually
disappear 10 to 15 minutes after eating sugar.
People differ slightly in the exact level of blood glucose at
which they begin to feel symptoms of low blood sugar.
What causes hypoglycaemia?
Insulin is normally produced in the pancreas and helps the cells
in the body absorb glucose from the blood. Normally, the glucose level rises
after a meal.
Too much insulin in the blood and other diseases can cause
hypoglycaemic episodes (also known as 'hypos').
What can cause hypoglycaemic episodes in non-diabetic
patients?
Too much insulin in the blood:
-
reactive hypoglycaemia (see below)
-
a tumour - very often benign - in the insulin-producing
pancreas
-
an overdose of
insulin or
diabetic tablets either by mistake or
on purpose.
Other diseases:
-
a disease in the adrenal glands (Addison's disease)
-
a weakened pituitary gland
-
a severe reduction in liver function
-
patients who have had their stomach removed
-
sometimes cancer
-
fasting, malnutrition
-
following alcohol ingestion.
Reactive hypoglycaemia
Reactive hypoglycaemia is possibly the most common reason for
hypoglycaemia in non-diabetics but is often overdiagnosed. This form of
hypoglycaemia is probably caused by an overproduction of insulin from the
pancreas after a large meal with a lot of carbohydrates. The insulin can still
be detected even after several hours, although the level should be back to
normal at this time. This condition is probably most common in
overweight people and those with
Type 2 diabetes,
where the large demand for insulin can sometimes cause too much insulin to be
produced in the pancreas. There is some evidence to suggest that reactive
hypoglycaemia can precede Type 2 diabetes.
What happens during a hypoglycaemic episode?
Hypoglycaemia can cause some or all of the following
symptoms:
-
paleness
-
trembling
-
perspiration
-
a feeling of weakness
-
rapid heartbeat
-
hunger
-
agitation
-
difficulty concentrating
-
irritability
-
fatigue
-
blurred vision
-
temporary loss of consciousness
-
convulsions
-
coma.
These symptoms will often occur about three to four hours after
a meal.
What can you do yourself?
If hypoglycaemia is suspected with the symptoms similar to those
above coming on three to four hours after a meal and going away after eating
sugar, it should be confirmed that the symptoms are caused by low blood
glucose.
Many people say they have hypoglycaemia without having low blood
glucose diagnosed!
The doctor should be contacted and, if possible, a
home blood glucose
apparatus obtained.
When the symptoms occur, measure the blood glucose level. If all
three of the criteria below are met, you should be referred for further
examination at a hospital.
-
Blood glucose level below 2.5mmol/l (millimole per litre) - or
sometimes slightly higher.
-
Some or all of the symptoms listed above.
-
The symptoms go away within 10 minutes of eating
sugar.
How is the diagnosis made?
The diagnosis is made by measuring the blood glucose level. If
the glucose level is below 2.5mmol/l, you have hypoglycaemia. If a tumour in
the pancreas is suspected, the patient is admitted to a hospital for
observation for three days, where the glucose level is closely
monitored.
If this drops below a certain point, the insulin level in the
blood is measured. If this is high, it suggests a tumour in the pancreas, which
will be looked for, and if found, removed.
Exercise and diet
Exercise lowers the blood glucose level but will normally not
cause hypoglycaemic episodes in otherwise healthy people.
If symptoms of hypoglycaemia are experienced during sport or
exercise, try eating some complex carbohydrates - starch, pasta for example -
before beginning. During the exercise consume simple carbohydrates like
glucose, in sports drinks for example.
When reactive hypoglycaemia has been diagnosed, the most
important thing to do is to change the diet. It should consist of a lot of
complex carbohydrates - potatoes, rice, pasta, etc - and be divided into more,
but smaller meals - breakfast, lunch, dinner and three in-between meals - to
avoid the big fluctuations in the insulin secretion from the pancreas.
How is hypoglycaemia treated?
Reactive hypoglycaemia is treated with diet changes as described
above. If a tumour in the pancreas is found, it is usually removed. However, if
this cannot be done, the condition can be controlled by injecting
sandostatin (Octreotide).
Weakened adrenal and pituitary glands are treated with medication.
|
Based on a text by Dr Jan Erik Henriksen and Professor Henning Beck-Nielsen
|
Last updated 15.09.2005
|
 |
|
|
 |
| |      |
|
