Diabetes is a disorder where there is an insulin deficiency. What this means is that your pancreas is unable to deliver enough insulin to control the rising blood glucose levels after eating. The main source of fuel or energy comes from the glucose in your diet. When you have diabetes this mismatch of insulin supply results in high blood glucose and well recognized symptoms.
Type 1 diabetes is a disorder where the insulin producing cells of the pancreas are destroyed resulting in very little insulin secretion.
In Type 2 diabetes the pancreas is still able to make insulin but needs a top up.
The manufacture of insulin is primarily designed to be either absorbed into the body slowly over many hours or rapidly.
Long acting insulin is prescribed to give you a constant background of insulin.
Rapid acting insulin is prescribed to control the blood glucose peak which occurs immediately after eating. Your doctor may prescribe a combination of both types of insulin.
Something to consider before deciding on an actual insulin regime is the type of insulin to be used. In this respect there are insulin preparations obtained from cows and pigs known as bovine and porcine insulin respectively.
There is human insulin, which is produced by a technique of genetic engineering using the human insulin gene sequence inserted into yeast cells in culture.
Finally insulin can also be designed in the laboratory to be absorbed either rapidly or very slowly. These are known as insulin analogues.
The main principle concerning the choice of any insulin regime is whether you decide to use a rapid acting insulin, a slowly absorbed background insulin or mixtures of both. The least intensive is once daily background insulin and the most intensive could be considered a background insulin plus rapid insulin before each meal. The insulin mixtures are intermediate and usually given twice daily before breakfast and before dinner although they are sometimes given at lunchtime as well.
Ways to administer Insulin
There are several ways that insulin can be administered.
The standard method for many decades has been via subcutaneous injection. This is where the insulin is injected just under the skin and then from there absorbed into the bloodstream.
Whether the insulin is delivered by syringe, pen injectors or insulin pumps the principle is the same. There are, however, small variations in the insulin molecule produced by different manufacturers and the speed of absorption into the body depends on this and on the solution in which it is dissolved for injection. This produces a wide variation of insulin preparations available for clinical use.
An alternative method of insulin delivery includes inhaled insulin, which was available for a short time but has now been taken off the market. Researchers are still exploring this avenue. Currently in development are oral insulin tablets and insulin contained in buccal sprays.