Type 1 Diabetes (IDDM) – INSULIN

Insulin is a hormone (chemicals synthesized by glands inside the body and released directly into blood to regulate the working of many organs and chemical pathways). It is synthesized by the Pancreas (a gland situated behind the stomach. Inside it there are beta cells of the Islets of Langerhans which do the actual work). Insulin helps the body to utilize glucose (main source of energy), fats and amino acids. It also helps the body to store the excess glucose as a compressed polymer called glycogen. It also promotes the formation of fats (triglycerides) and proteins and their storage in the body. In doing these functions, it helps to lower the blood sugar and lipid levels.


Normal Glucose uptake

Diabetes is a disease characterized by inadequate insulin activity, either because of inadequate production (pancreatic damage) or inadequate response by the insulin receptors (similar to damaged electrical plug points) to circulating insulin. When we give external insulin to such diabetics, we either make up the deficit or increase insulin activity to such a level that the receptors are forced to respond.

  • Insulin is the only solution to type 1diabetes, as it is the absence of insulin that causes the disease.
  • Insulin works very effectively as an injection and can be taken through syringes, insulin pumps or insulin pens
  • It does not work as a pill because the strong gastric juices would destroy its delicate structure.
  • It is essential to take Insulin in the correct dose, at the appropriate site and with proper technique.

Types of insulin :

Insulin earlier was extracted from the pancreas of pigs or bovine sources, obtained from slaughter houses. Now-a-days, most of the insulin is obtained from genetically modified bacteria (recombinant DNA Techniques) that have been programmed to produce insulin. Some animal insulin is still available that is chemically modified to resemble human insulin, since human insulin is chemically very slightly different from pig and bovine insulin.

Doctors prefer human or humanoid insulin because of the lower risk of allergies, though a school also says that it is not the species but the purity of insulin that determines the risk of allergy.

Insulin is available in various forms depending on:

  • Source of Origin : Recombinant (human), porcine (pigs), bovine (cows)

Duration of Action : Ultra short acting (insulin lispro), Short acting (Regular), Intermediate acting (Lente and NPH), Long acting (Ultra-Lente and Protamine Zinc insulin)

Single Component Insulins Onset of action* Peak activity* Duration of action*
Ultra short acting (insulin lispro) 15 to 20 minutes 1 hour 4 hours
Short acting (Regular or Soluble) 1/2 to 1 hour 2 to 4 hours 6 to 8 hours
Lente 1 to 2 hours 6 to 12 hours 20 to 24 hours
NPH (Isophane) 1 to 2 hours 6 to 12 hours 20 to 24 hours
Ultralente 4 to 6 hours 16 to 18 hours 24 to 36 hours
Protamine Zinc insulin 4 to 6 hours 14 to 20 hours 24 to 36 hours

* Varies from person to person and from time to time in a given person.

Insulin mixture (mixed insulin) contain regular insulin and NPH insulin in a pre-defined ratio.

Insulin from different origins should not be mixed. It is the experience of your doctor to choose just the right insulin for a particular purpose or illness episode at a dose which he thinks will suit.

Insulin syringe

  • An insulin syringe is different from other syringes as it is marked into 40 units per 1 ml or 100 units per 1 ml.
  • The needle is also ultra thin to minimize pain, and is only 1 cm long so that it only goes into the layer below the skin.
  • Insulin injections have now been made easier to give with the help of Insulin pens with replaceable cartridges of various insulin. These do not need to be refrigerated and can be carried in ones bag. They have a meter to dial the exact dose, and a press of a button delivers the exact dose.
  • Experimentalinsulin pumps and nasal drops etc. are now being tried and we may see easier methods of insulin delivery in future.

Sites of injection

  • Insulin has to be taken as a subcutaneous injection i.e. in the fat layer beneath the skin.


  • The ideal site for injection is the abdomen as the absorption/uptake is very consistent from this part of the body. Injection may also be taken at the thighs, hips and upper arms.
  • Rotate the site of injection within the same region (abdomen, thigh, hips, upper arm, flanks) frequently.
  • Change the region of injection at regular intervals (see chart for help).
  • It is important to remember that insulin absorption differs in different areas. It is fastest from abdomen (belly), slower from the arms, more slowly from thighs and slowest from the buttocks.

Cleaning the site of injection

70% alcohol is a better choice than 90% alcohol for cleaning the site. In case, alcohol is not available soap and water is an alternative. Whatever method is used for cleaning it is important to let the area dry before injection.

Preparation for an injection

  • Wash your hands with soap and water.
  • Push the plunger in the syringe up and down 2-3 times; this makes drawing a dose easier.


  • Wipe the top of the insulin bottle, not the needle (as this may remove the silicon coating on the needle and make the injection more painful).
  • Draw air equal to the amount of insulin to be taken in the syringe and inject t into the upright bottle, not into an up side down bottle


  • Now turn the bottle up side down and withdraw the needed amount of insulin.


  • Draw the CLEAR (Short Acting) Insulin first. It may be followed by drawing of the CLOUDY (Long Acting) insulin, if required.


  • Double check the dose withdrawn.
  • Warm the syringe in the palm of your hand.

How to inject insulin

  • Pinch the skin between your index finger and thumb, at the site of injection.


  • Push the needle beneath the skin, holding the body of the syringe and not the plunger.


  • Leave the pinched site.
  • Now, push the plunger and the drug dose is delivered into the site.


  • Count 5 to 8 and then remove the needle. This decreases chances of insulin leaking back.
  • Place a dry cotton swab and press firmly.

Storage of Insulin

  • Store insulin vials in the butter / egg shelf of your refrigerator and never in the freezer.
  • The vial in use can be stored at room temperature in a cool dark place.
  • Do not expose the vials to direct sunlight.
  • Do not store insulin near electronic or electrical devices that get heated.


  • Check that the regular insulin is absolutely clear and does not have even traces of turbidity.
  • Gently rotate the vial of insulin in your palms before use, do not shake it up and down.
  • Do not take insulin straight from the fridge as it is cold and therefore, the injection may be more painful.
  • Never take a hot bath soon after injection.
  • Do not inject in the limb to be used in an exercise soon after.
  • NEVER MIX INSULIN of DIFFERENT ORIGINS (like insulin got from human, porcine or bovine origins).
  • Double check the dose taken in the syringe.
  • Use a syringe specially made for taking insulin injections (called insulin syringes), not the other syringes available in the market as this may cause variation in the administered dose. Avoid usage of glass syringes.

Use a syringe for 2 to 3 days and not beyond.