Improving diabetes injection technique

It is estimated that almost 30% of people with diabetes in the UK are using injectable therapies. Since there are now as many as 2.75 million people in the UK with diabetes,1 this equates to approximately 800,000 people using injectable therapies.2 Both insulin and the newer incretin mimetics, such as Exenatide or Liraglutide (also known as GLP-1 agonists), are highly advanced therapies but expensive. There has been considerable emphasis on the pharmacokinetics and pharmacodynamics of both. However, there has been very little consideration given to the key aspects of the technique in which the drug is injected. For these injected therapies to work optimally, correct injection technique is essential. Incorrect technique (including using the incorrect needle length) can lead to these injectable therapies not being absorbed in a predictable manner. This, in turn, may cause immediate problems such as hypoglycaemia (a sudden drop in blood sugar because of accelerated insulin absorption) and/or hyperglycaemia (a rise in blood sugar because of slow insulin absorption or insulin running out too quickly). Other potential injection problems include lipohypertrophy (accumulation of fat under the skin caused by injecting to frequently in the same area), and – although uncommon – lipoatrophy (wasting of the subcutaneous tissue) or bruising and bleeding at the injection site.

The risk of this could be reduced by improving and stressing the importance injection technique. There have been advances in the devices used to deliver injectable therapies; the progression to the use of pen devices is a positive one as they have been proven to help people manage their injectable therapies more easily, safely and accurately.3 The recommended site for insulin and incretin mimetic injections is the subcutaneous (SC) tissue (the layer of fat below the skin).4 Injecting into the muscle can accelerate absorption of insulin, thus increasing the risk of hypoglycaemia5,6 and responsive hyperglycaemia (as the insulin runs out more quickly). Injection into the subcutaneous layer allows the insulin to be absorbed at a more predictable rate, which can result in better glycaemic control.7 Studies have demonstrated that it does not matter if insulin is injected just under the dermis or just above the muscle, as long as it is injected into fat.8 The main points of discussion in this article will centre on the international recommendations and proposed national recommendations of injection technique with a particular focus on lipohypertrophy.

International injection technique workshop