Benefits of Insulin Pump Therapy

Insulin pump therapy provides an effective means of achieving near-normoglycaemia in people with diabetes. As an intensive treatment option it offers a number of advantages over conventional insulin therapy.

Natural supply of insulin

An insulin pump provides a continuous supply of insulin throughout the day and night (basal insulin) and extra boosts are given before eating (bolus insulin). The basal insulin takes care of your background insulin needs and the bolus insulin is tailored to your food intake. So, the insulin pump will give you the most natural method of insulin delivery.

Reliable supply of insulin

The basal insulin is supplied as a very small amount every few minutes and only short acting insulin is used with a pump. This means that there are no problems with variable absorption of insulin and those unpredictable swings in blood glucose levels can be avoided.

Insulin supply tailored to your needs

The amount of background insulin - the basal rate - can be set at different levels through the day and night, according to your own needs. This means that you can have the pump automatically deliver more background insulin when you need it - in the early hours of the morning, for example - just as the body would naturally provide it. Using an insulin pump can ensure stable blood glucose levels through the night, coping with the dawn effect, but without increasing the risk of nighttime hypos.

Eat what you want, when you want

The continuous trickle of basal insulin also takes care of your daytime needs when you are not eating. At mealtimes, or if you fancy a snack, you set the pump to deliver extra insulin. The amount of insulin – the bolus dose – can be tailored exactly to what you eat and how much of it. When you choose to eat is up to you.

Sleep in at weekends

The basal insulin continuously supplied by the pump will keep blood glucose levels steady throughout the night and into the day without any input from you. This means that you can sleep in and not have to worry about blood glucose levels rising. You can eat breakfast when, or if, you choose to.

Exercise spontaneously

The basal rate can be altered temporarily at any time. So, if you suddenly decide to go for a jog, or you are unexpectedly invited to play a game of tennis, you can simply decrease the basal rate whilst you exercise. This means that you no longer need to plan exercise in advance or eat large amounts of carbohydrate beforehand in order to avoid hypoglycaemia.

Adapt your insulin to your changing needs

In addition, using an insulin pump can help you to cope more effectively with increased blood glucose levels that frequently accompany periods of stress or illness. Travelling, too, is made a whole lot easier, especially on long haul journeys and when you need to adapt to new time zones.

Tight control without more hypos

With a pump, you can tailor your insulin supply to fit your exact needs. In this way it is possible to achieve tight control of blood glucose levels without having to increase the risk of hypos.

No need for multiple injections

The pump is worn all the time and all the insulin is delivered through a fine plastic tube (known as the infusion set), which is inserted under the skin (usually in the abdomen). There is no need for any injections, once the infusion set is in place. The infusion set msut be replaced every 2-3 days.

The insulin pump provides the most accurate, precise and flexible system of insulin delivery currently available. Insulin pump therapy gives you the freedom to live life to the full, whilst keeping blood glucose levels stable and well controlled.

Clinical benefits

Glycaemic control

The Diabetes Control and Complications Trial (DCCT) clearly established that intensive therapy could facilitate a considerable improvement in glycaemic control and this was associated with a significant reduction in risk of development and/or progression of microvascular and neurological complications (1). Continuous subcutaneous insulin infusion (CSII) was successfully used in the DCCT to this effect (2).

Precise and reproducible insulin delivery

Rates of absorption of subcutaneously injected insulin have been shown to vary significantly, especially with intermediate and long acting insulins (3,4) and this may contribute to problems in achieving glycaemic control in many people. Increased mobilisation of subcutaneous insulin depots is facilitated by increased blood flow which may occur during exercise and warm baths (5) and this can cause sudden or unexpected hypoglycaemia. CSII employs only rapid acting insulin which is delivered continuously in very small amounts. Consequently, variability in insulin absorption is minimised in CSII (6) and this ensures a reliable insulin supply with reproducible post-prandial peaks.

Physiological insulin delivery

CSII, with the option of different programmable basal rates, enables the individual's physiological insulin requirements to be met. In particular, early morning increases in blood glucose concentrations and insulin requirements (known as the 'dawn effect') provide particular problems for people with diabetes. Increasing injected insulin in order to counteract high blood glucose levels on waking increases the risk of nocturnal hypoglycaemia. Using CSII, an appropriately timed step-up in insulin delivery during the early hours of the morning can successfully prevent the dawn effect (7,8).

Reduction in severe hypoglycaemia and hypoglycaemia unawareness

The DCCT documented a three-fold increased risk of severe hypoglycaemia in those patients receiving intensive insulin therapy either by way of multiple injections or CSII (9). However, this increased risk actually ranged from 1 to 11 fold across the 29 centres (2) which suggests that factors other than simply the intensive therapy may have played a part.

A number of studies have demonstrated a reduction in the occurrence of severe hypoglycaemia in patients using CSII (10-13). Of note, in the latter study, the use of insulin lispro in CSII was reported not to affect the counterregulatory hormone response to hypoglycaemia (13). Kanc and associates reported a significant improvement in hypoglycaemia warning symptoms on substituting nighttime CSII (using the regular human insulin, Velosulin) for bedtime NPH insulin (14). Another recent report suggested that the use of insulin lispro improved the sensitivity of the liver to glucagon; it was proposed that increased hepatic glucose output in response to mild hypoglycaemia could potentially reduce the risk of severe hypoglycaemia (15). These studies suggest that CSII may be a favourable treatment option for patients encountering problems with severe hypoglycaemia or hypoglycaemia unawareness on conventional injection regimens.

In pregnancy

Optimisation of glycaemic control, both prior to conception and during pregnancy, is essential for a successful outcome (16,17). CSII can provide a means of normalising blood glucose levels during this critical period (18-20). Insulin pump therapy also affords flexibility, which may be of particular importance during the first trimester, when morning sickness and a tendency towards hypoglycaemia with loss of warning symptoms may compromise glycaemic control. The ability to adjust insulin doses quickly with a pump also makes control of blood sugars during labour, during delivery and post delivery much more predictable.

Patient lifestyle benefits

Flexibility of lifestyle

The successful outcome of any intensive insulin treatment is dependent upon a number of factors, one of the most critical being compliance. Many patients find their lifestyle restricted by insulin injection therapy, particularly with respect to the timing of meals and the need to plan activities; this can hinder compliance and the ability to achieve desirable levels of blood glucose control.

The ability to tailor bolus insulin delivery to the individual's food intake, independently of the basal rate, allows flexibility in terms of meal timing. This allows the user to successfully accommodate changes in daily routine that are often enforced e.g. through travel or variable working hours.

Problems encountered with the "dawn effect" may be compounded at weekends and during holidays when patients wake later. Insulin pump therapy eliminates the need for early morning injections and facilitates better blood glucose control on such occasions (21). Patients using CSII are therefore able to delay (or even omit) breakfast without compromising glycaemic control.

Improved quality of life

CSII thus obviates the need for adherence to a strict daily schedule and this flexibility may increase the quality of life in selected patients, in addition to improving glycaemic control. A number of studies have reported an improved quality of life associated with CSII therapy (22-24).

A survey among pump users in the USA, Germany, the Netherlands and Austria was conducted. When directly asked about their quality of life 98% of people responded by saying that they experience a better, or even much better, quality of life using an insulin pump.

The advantages of CSII over conventional insulin injection therapy are centred upon the ability to provide a physiological insulin supply that can be specifically tailored to the individual's requirements. This enables optimisation of glycaemic control whilst allowing greater flexibility of lifestyle.

For Full References which are in Clinical Research Papers/Abstracts - click here