Types of insulin therapy

Photo of a young man and a doctor (PantherMedia / Alexander Raths)

The aim of insulin therapy in diabetes is to make up for the lack of insulin in the body, to lower blood sugar levels, and prevent long-term complications as much as possible. There are different types of insulin therapy. All of them aim to regulate blood sugar levels in order to keep them from getting too high or too low.

Blood sugar (glucose) levels are not only affected by the amount of insulin you inject, but also by what you eat and drink, as well as how much energy you use during physical activity. The time of day, inflammatory diseases, other medications and hormonal changes can influence your blood sugar levels too. So it's especially important to know your body and habits well when dealing with diabetes – that's the only way to optimally adjust your insulin therapy.

There are various types of insulin. They mainly differ in how long their effect lasts. Some types of insulin cover your body's basic needs: they work slowly and constantly over half a day or a whole day (intermediate-acting or long-acting insulin). “Short-acting” insulin is used at mealtimes to provide the insulin needed right after eating.

Nowadays, people with diabetes can mostly choose one of the various types of insulin therapy themselves in order to fit it into their daily routine as well as possible. Most people with type 1 diabetes choose “intensive” insulin therapy.

Conventional insulin therapy

Conventional insulin therapy involves injecting insulin twice a day. This approach is often chosen by people who have a fairly regular daily routine and prefer to inject their insulin at the same times every day.

Conventional insulin therapy involves injecting intermediate-acting or long-acting insulin that works for at least half a day. This type of insulin can either be used alone or together with short-acting insulin. Most people use a standard mixture of short-acting and longer-acting insulin. They inject this mixture once before breakfast and once before the evening meal. In order to compensate for the effect of insulin, they have to eat fixed amounts of food regularly over the course of the day. People who do a lot of physical exercise can balance their blood sugar out by eating extra snacks between meals. So, with conventional insulin therapy, meals and physical exercise are planned around the insulin.

Choosing conventional insulin therapy can mean leading a fairly regimented lifestyle. And, compared with intensive insulin therapy, conventional insulin therapy is much less effective at preventing complications associated with type 1 diabetes. So it's usually only considered as a treatment option for people with type 1 diabetes who can’t have intensive insulin therapy.

Intensive insulin therapy

In intensive insulin therapy, the amount of insulin can be adjusted flexibly and spontaneously based on a person’s blood sugar levels, how much they eat and how physically active they are. Regular blood sugar monitoring is essential here. You can either inject yourself several times a day, or use an insulin pump to do so. In order to cover basic insulin needs, longer-acting insulin is injected once or twice a day. This is often referred to as “basal insulin.” Short-acting insulin is also injected before each meal in order to allow the body to process the carbohydrates in the food. This is known as a “bolus dose” or “mealtime insulin.”

People who have an insulin pump only use short-acting insulin. The pump regularly delivers small amounts of insulin to continuously cover the body's basic needs.

One goal of intensive insulin therapy is to keep blood sugar at almost normal levels. It also aims to allow greater flexibility in how you lead your life. There is no need to eat meals at fixed times or make sure you always eat the same amount of carbohydrates. Instead, you inject as much insulin as you need at the time. The amount of insulin needed will also depend on your blood sugar levels, the time of day and whether you plan to be physically active. If you inject too much insulin, your blood sugar levels may drop too low. If you inject too little, they may be too high.

Intensive insulin therapy has been shown to have health benefits compared to conventional insulin therapy. It can lower the risk of developing diabetes-related complications, particularly those affecting the eyes, kidneys, and nervous system.

Patient education programs

People who need insulin therapy have to learn various skills, like measuring their blood sugar. In Germany there are education programs to help people manage their diabetes. These are offered as part of disease management programs (DMPs) for type 1 and type 2 diabetes. People learn how best to adjust their diet, sports activities and other physical activities to complement their insulin therapy and other blood-sugar-lowering medications.

Modern diabetes treatment involves coordinating normal activities of daily life and the self-management of blood sugar as effectively as possible, while making the best use of medical care, including medication. People who are well informed about their diabetes, and follow their treatment plan properly, can avoid associated complications and lead nearly as flexible a life as people who do not have diabetes.