Insulin pump therapy: From cradle to grave

Thomas Ulahannan (Consultant Physician, Gloucester and Conference Chair) opened the conference and welcomed delegates to the event.

Session 1
Fiona Campbell (Consultant Paediatrician and Diabetologist, Leeds) began her talk on integrating technology by looking at key milestones that have improved access to insulin pumps over the past decade. She pointed out that the latest NICE (2008) guidance on insulin pump therapy has improved access to the technology, but “compared with Europe, the UK still has a long way to go”, she said.

She focused on the insulin pump service in Leeds, and the consultation process in particular. “It is important to have a structured approach to interpretation of the insulin pump data”, she said, and emphasised the importance of the individual, or their family, taking ownership of the condition. “A measure of success for the child and family may not be a reduction in HbA_1c, as it might be for the healthcare professional, but simply that their child no longer had episodes of hypoglycaemia in the middle of their Saturday afternoon football match”, she said. She advised delegates to take time to read the data downloaded from the insulin pump before the consultation so that it is easier to focus on and address specific aspects of their glycaemic control.

Dr Campbell also emphasised the importance of education for people using multiple daily injections (MDIs) or continuous subcutaneous insulin infusion (CSII) to manage their diabetes and for healthcare professionals. “Despite all the benefits of newer technologies for diabetes management, good education is still the key to improving glycaemic control”, she said.

The next talk – continuous glucose monitoring (CGM) as a standalone intervention in pregnancy and with sensor-augmented pumps – was delivered by Peter Hammond (Consultant in General Medicine, Harrogate). Dr Hammond began by looking at some practical aspects of sensor-augmented CSII in pregnant women. These included: setting the high glucose alarm as low as 7.6 mmol/L because tight control of blood glucose levels is key; finding alternative sites for the sensor, as most women do not want something in addition to the insulin pump infusion set on their abdomen; and emphasised that education is important.

Dr Hammond discussed the use of CGM as an educational tool. “It is clear from the CGM just how suboptimal an individual’s glycaemic control is. This can be useful in demonstrating the risk to the foetus”, he said.

He looked in detail at a study by Murphy et al (2008), who conducted an open-label randomised controlled trial of the impact of intermittent blinded CGM throughout pregnancy in 71 women with diabetes. There was a difference in HbA_1c level between women using CGM and women receiving standard antenatal care at 32–36 weeks’ gestation (5.8% [40 mmol/mol] vs 6.4% [46 mmol/mol], respectively). “Babies born to mothers using CGM had a lower birth weight and a reduced risk of macrosomia”, said Dr Hammond.

One of the delegates asked whether midwives should be trained in insulin pump therapy and Dr Hammond said: “Absolutely! It is important that the midwife has seen the insulin pump before the woman goes into labour. We have designed a protocol for the management of people with diabetes using insulin pumps in other clinical situations, such as labour or surgery”. 

Thomas Ulahannan was next to speak on enhancing intensification and looked first at the insulin:carbohydrate ratio. He said that at initiation of CSII, getting the correct basal rate has the biggest impact on glycaemic control. “As HbA_1c level decreases, the postprandial glucose level becomes the most important to address.” He pointed out to delegates that circadian rhythm also impacts insulin requirements as different levels of hormones are released throughout the day.

He then spoke about different types of bolus dose. “The standard bolus is best for high-carbohydrate, low-fat and low-protein meals, and the square-wave bolus is most appropriate for high-fat or high-protein meals and in people with gastroparesis”, he said. He also emphasised that the evidence for different types of bolus dose is not as strong as one would expect and there is substantial variation between individuals. He also mentioned that the commonly used 50:50 ratio (of basal to bolus insulin) is useful at diagnosis but will need to be adjusted in each individual.

Session 2: Masterclasses
After lunch, the first masterclass was held by Fiona Campbell and Carole Gelder (Clinical Educator and Children’s Diabetes Nurse Specialist, Leeds), on the subject of CSII in children under 2 years of age. Carole explored the strategies for safe and effective initiation of insulin pump therapy in this age group and looked at the specific challenges that children of this age present. One particular challenge she identified was the need for tiny insulin doses to match the frequent meals and snacks that babies and toddlers require throughout the day, to minimise glycaemic variability and hypoglycaemic unawareness.

Carole also commented on the parental fear of hypoglycaemia being a barrier to optimal glycaemic control and led a discussion on how to overcome this.

Gill Morrison (Diabetes and CSII Specialist Nurse and Co-Chair of the Insulin Pump Association, Liverpool) looked at pumps for older people in the second masterclass, highlighting that there is no specific evidence about working with older people and CSII. Gill discussed the issues around initiating CSII in older people who use MDI but are experiencing erratic glycaemic control – particularly those with frequent hypoglycaemia, which may also be associated with unawareness. She also emphasised that there is a need for simpler insulin pumps for this age group. 

Gill gave the delegates pragmatic advice regarding initiation of CSII therapy in older people including setting realistic targets, such as, reducing episodes of hypoglycaemia and regular follow-up. She also emphasised the use of various learning strategies to help with education, for example, pictures of foods that have the required bolus dose printed on them.

Gill pointed out that in her clinic she sees people who were initiated on CSII 10 years ago and some of these individuals are now be considered “older” people. This can create challenges, as an older person’s learning can be detrimentally affected as a result of the ageing process, thus causing a problem when insulin pumps need to be updated because the model and type of consumables must be changed. 

The third masterclass was on new technologies. Candice Ward (Principal Diabetes Dietitian, Cambridge) began by looking at currently available new pumps like the Animas^® Vibe^TM (Animas, High Wycombe) and OmniPod^® (Insulet Corporation, Bedford, USA) and up-and-coming patch pumps such as the Cellnovo (Cellnovo, London) and Solo^TM MicroPump (Medingo Ltd., Israel). She explained that a patch pump is controlled remotely using a hand-held device, while the pump and insulin reservoir is much smaller than a traditional tethered pump and may have a small, or no, infusion tube. She also briefly discussed other ways of delivering insulin subcutaneously, for example, via the DiaPort® (Roche Diagnostics, Burgess Hill; a surgically implanted permanent port through which insulin is delivered) and, even faster acting insulins that are currently in development.

Candice then discussed closed-loop or “artificial pancreas” research taking place in Cambridge and looked at a recently completed study that tested the closed-loop algorithm overnight when participants had consumed a significant amount of alcohol the previous evening. The closed-loop system demonstrated improved glycaemic control and reduced hypoglycaemia compared with those not using the closed-loop overnight (Kumareswaran et al, 2010). 

Candice also looked at the current evidence to support CGM and its use. At this time there is not sufficient evidence published to support the NHS funding its use. However, she informed delegates that there are many trials currently underway that are gathering more evidence, such as the large randomised controlled trial (HypoCOMPASS), looking at the prevention of severe hypoglycaemia in people using CSII or MDIs with or without CGM.

Session 3
Gill Morrison gave the next talk on insulin pumps in end-stage renal failure. Renal patients often have multiple complications associated with their diabetes that may have a negative impact on glycaemic control – this is without even considering the impact of renal replacement therapy on blood glucose stability itself.

Insulin pump therapy may be a means to more effectively manage glycaemic control for those using dialysis and allow more flexibility with diet and food choices. However, Gill stressed that there are a lot of practical considerations to take into account, such as the type of dialysis, the method used and if dextrose is being used in the dialysis process. 

“Our patients are educated so that they are empowered to effectively manage their diabetes during periods of dialysis”, said Gill. She stressed that this education should begin well before starting dialysis, with the patients having clear guidelines about when they should contact the diabetes or dialysis teams.

Peter Hammond delivered the final talk of the day on transition care for adolescents. “One of the features of adolescents in general is risk-taking behaviour, which is no different for adolescents with diabetes”, he said. Adolescents may forget to take bolus doses or simply not worry about their diabetes control. Dr Hammond emphasised the importance of eating meals together as a family, as it seems to play a role in reducing this risk-taking behaviour.

Dr Hammond then referred to the NICE (2008) guidance that recommends a trial of MDIs in adolescents, commenting that “it doesn’t make a good first impression if the adult consultant takes away your pump!”. He recommended that first, it should be established who is managing the adolescent’s diabetes – is it them or their parents? They may wish to choose a different insulin pump if it suits them better than their parents. Finally, he recommended that the adolescent go to a transition and pump clinic until they feel ready to move into the adult service.