 What is diabetes?Diabetes
mellitus is a chronic and currently incurable condition in which too much glucose (sugar)
is present in the blood.
This arises because the body cannot use the glucose properly, either because of a lack
of the hormone insulin or because the insulin available does not work effectively. Not
only is excess sugar found in the blood but it may appear in the urine too.
The name diabetes mellitus derives from the Greek word 'diabetes' meaning siphon - to
pass through, and 'mellitus,' the Latin for honeyed or sweet. It refers to a major symptom
of diabetes, sugar in the urine, and is a far more acceptable name than the one it was
known by in the 17th Century - when it was called the 'pissing evil.'
Diabetes has been a recognised condition for over 3,500 years. About 2,000 years ago,
it's said that Arataeus of Cappadocia described diabetes as 'a melting down of the flesh
and limbs into urine.' This reflected the weight loss and excess passing of urine that
occurs in acute, undiagnosed diabetes.
Diabetes is common, and 1.4 million people* in the UK are known to have it. However, an
equal number, if not more, are believed to have diabetes yet not know it. More than
three-quarters of those with diabetes have what is now called Type 2 Diabetes Mellitus.
This used to be known by the other names of 'non-insulin dependent diabetes mellitus
(NIDDM)' and 'maturity-onset diabetes mellitus'. The remainder have Type 1 Diabetes
Mellitus, which used to be known as 'insulin-dependent diabetes mellitus.'
* Stats supplied by Diabetes UK
Types of diabetes
There are two main types of diabetes:
In Type 1, the body is unable to produce any insulin. This usually starts in
childhood or young adulthood. It is treated with diet control and insulin injections. Type
1 diabetes used to be called 'insulin-dependent diabetes.'
In Type 2 diabetes, not enough insulin is produced or the insulin that is made
does not work properly. This tends to affect people as they get older, and usually appears
after the age of forty. It used to be known as 'maturity-onset diabetes' or 'non-insulin
dependent diabetes (NIDDM).'
Normal blood sugar control
In the body, glucose is converted into energy. This glucose comes ready-made in sweet
foods such as sweets and cakes, or from starchy foods such as potatoes, pasta, or bread
when they are digested. The liver is also able to manufacture glucose.
Under normal circumstances the hormone insulin, which is made by the pancreas,
carefully regulates how much glucose is in the blood. Insulin stimulates cells to absorb
enough glucose from the blood for the energy, or fuel, that they need. Insulin also
stimulates the liver to absorb and store any glucose that's left over. After a meal the
amount of glucose in the blood rises, and this triggers the release of insulin. When blood
glucose levels fall, during exercise for example, insulin levels fall too. A second
hormone manufactured by the pancreas is called glucagon. It stimulates the liver to
release glucose when it's needed, and this raises the level of glucose in the blood.
Insulin is manufactured and stored in the pancreas, which is a thin gland about 6
inches long that lies crosswise behind the stomach. It's often described as being two
glands in one, since in addition to making insulin it also produces enzymes that are vital
for digestion of food. These include lipase, which helps to digest fat, and amylase that
helps to digest starchy foods. It also releases 'bicarbonate of soda' to neutralise any
stomach acid that may otherwise damage the lining of the gut. |
