Diabetes occurs when the pancreas does not produce enough insulin to help glucose enter the cells, or the insulin which is produced does not work properly (insulin resistance).
Insulin is the hormone, produced by the pancreas, which allows glucose to enter cells, where it is used as fuel for energy.
Glucose comes from digested carbohydrates, and is produced by the liver. Typical carbohydrate sources are bread, vegetables, and fruit. Because the diabetic cannot make proper use of glucose, it builds up in the blood, but is not used as fuel.
Type 1 (insulin dependent) :
Type 1 develops when the insulin producing cells in the body have been destroyed, so the body has an absence of insulin. Onset is usually before the age of 40, and accounts for between 5 and 15 per cent of all instances of diabetes. Treatment is by daily insulin injections, a healthy diet, and regular physical activity.
Type 2 (non-insulin dependent):
Type 2 develops when the body does not make enough insulin, or the insulin that is produced does not work properly (insulin resistance); the onset is usually after the age of 40, or 25 in Africans and South Asians. Type 2 diabetes accounts for between 85 and 95 per cent of all cases, and is treated with a healthy diet and increased physical activity. Medication and supplemental insulin may also be required.
Blood sugar levels (mmol/L):
Subject typeBefore meals2 hours after meals
Non diabetic4 - 5.9< 7.8
Type 2 diabetic4 - 7< 8.5
Type 1 diabetic (adult)4 - 7< 9
Type 1 diabetic (child)4 - 8< 10