The role of insulin pump therapy 25 years on

Abstract

The development of a pump for the delivery of insulin was initiated in the United Kingdom in the late 1970s by a group of researchers at Guys Hospital, London, led by Professor Harry Keen and including myself. Professor Keen wanted to reproduce the physiological release of insulin in order to investigate the link between strict diabetic control and complications. Concerns about efficacy Concerns about safety The belief that pumps would be widely used for people with type 1 diabetes, thus incurring large costs for the NHS In terms of efficacy, a meta-analysis of 11 studies between 1982 and 2000 comparing pumps with the best injection therapy has shown that glycaemic control is significantly better with pump delivery of insulin. However, people with significant psychiatric problems are not indicated for pump therapy and tend to do badly. In terms of, safety, the myth that hypoglycaemia is more common with pump therapy is probably due to the unusually high incidence of episodes reported in the DCCT, but this has not been confirmed by any other major trial. Another myth – that diabetic ketoacidosis (DKA) is more common with pumps – has also been shown not to be true. The incidence of DKA is the same on pump therapy as with multiple injection and the rate improves with experience. In terms of usage and costs, pump therapy is not indicated for the majority of people with diabetes in the United Kingdom. It is indicated for people with type 1 diabetes who do not achieve good control with optimised injection therapy and have problems with frequent unpredictable hypoglycaemia. Patients with erratic lifestyles are better on pump therapy. The best way forward in the United Kingdom is to develop simple clinical guidelines in order to identify those patients most suitable for pump therapy. Ideally, patients using pumps should be managed in regional pump centres, because it is necessary to have staff with experience of CSII and the necessary technical expertise to manage a fair number of patients. Health authorities should be persuaded that they will not have to spend a great deal of money, as pump therapy is only indicated for a small number of patients, and funds should be allotted to regional centres. In conclusion, the wider application of CSII in the United Kingdom is justified, as pump therapy is safe, effective and affordable. Should pump therapy be managed by general practitioners (GPs)? I think not at this stage. In the first instance, I think that the medical establishment, and possibly NICE, should agree a policy on the safety and efficacy of pumps. Diabetologists could then organise regional centres and enter into contracts with the health authorities. By excluding GPs are we not in danger of creating another area of mystery in diabetes, where people cannot do something because they have not been taught how to do it? People on pump therapy still have GPs: how can these doctors help them if they know nothing about pumps? That is a fair point. We have to find some way of ensuring that GPs understand pump therapy so that they can provide back-up, as indeed they do with optimised injection therapy. Has optimised injection therapy been given a fair trial? Before we consider patients for pump therapy, they have to go through a prolonged period of trial using optimised injection therapy. I have a concern that we are only looking at pump therapy from a medical point of view. We are saying that patients can only use pumps for specific indications. But what about their preferences and choices? A lot of research has been carried out on patient choice and reactions to CSII; this has been overwhelmingly favourable. We have studied patient reactions when designing pumps: from technological, management and psychological points of view. In fact, one of the main drives behind the renewed interest in CSII has come from patients. In this respect, there is a parallel with insulin pen therapy, which was initially discouraged by doctors and pushed forward by patients.