Diabetes

Diabetes is a condition related to the ability of the body to regulate the amount of sugar (glucose) in the blood. It is an increasingly common condition that affects many people worldwide.

The amount of sugar in the blood is usually regulated by the hormone insulin, which is produced and secreted by the Beta cells (B-cells) of the pancreas. The pancreas is an endocrine gland - see the brief description on the page about endocrine glands.

‘Normal’ blood glucose levels are in the range
4-10 m.mol / litre, where m.mol / litre (of glucose) is a measure of the concentration of sugar (in form of glucose) in blood.

These figures generally refer to measurements taken with approximately 2 hours of eating a meal.

Variations within this range may be explained by how recently foods were consumed, the sugar-content of those foods, and how quickly the sugars in that type of food are released into the body.

In the context of diabetes, and blood sugar levels:

• 'Hypo' refers to there being less than 3.5 m.mol / litre (of glucose) per litre of blood.
  Symptoms may include sweating, shakes and light-headedness.
  If the level continues to drop then the person may fall into a coma.
  If it drops still further, death may result.

• 'Hyper' refers to there being more than 10.1 m.mol / litre (of glucose) per litre of blood.
  Symptoms may include urination, headaches, blurred vision and keto-acidosis.
  If the level continues to increase then the person may fall into a coma.
  If it increases still further, then death may result.

The cycle of regulation of blood sugar levels in a person not affected by diabetes is shown below.

The basic cycle summarised in the diagram above is:

• Normal blood glucose
• Increase in blood glucose (following a meal or snack)
• Beta-cells in the pancreas are stimulated to produce insulin
• Blood glucose level falls
• Normal blood glucose
• Blood glucose level falls
• Alpha-cells secret glucagen (to glucose)
• Blood glucose levels rise

This cycle is repeated throughout the day as the person becomes hungry, eats, ingests sugars (see types of sugars), and processes them.

There are several different types of diabetes. 5 types of diabetes and their causes and symptoms are listed (in alphabetical order) in the following table:

Type of Diabetes Causes & Symptoms 1. Diabetes Insipidus is due to non-secretion of the hormone A.D.H.. 2. Diabetes Melitis is the failure of the body to produce any insulin. It is also known as ‘Pissing Evil’, and ‘Sugar Fountain’ – because the urine smells very sweet. 3. Diabetes Type I is also known as ‘juvenile diabetes’. It is hereditary and occurs in young people. 4. Diabetes Type II ('Hypoglycaemia') is non-insulin dependent. The pancreas produces some insulin, but insufficient. This condition is associated with age, obesity and lack of exercise and is normally cured by some combination of tablets / diet / exercise. 5. Temporary / Pregnancy Diabetes occurs because of the hormonal disruption caused by ‘feeding for two’. Symptoms end with the end of the pregnancy.

See also notes about the composition of blood and aspects of the endocrine system such as conditions affecting the endocrine system.