Study unveils insulin pump and injection comparison
Insulin pumps do not achieve better blood glucose control compared to multiple daily injections, according to a study.
Research showed groups of people on both treatment regimes showed clinically relevant and long lasting decreases in HbA1c, rates of severe hypoglycaemia, and improved psychological measures, although few participants achieved glucose levels currently recommended by national and international guidelines.
However, writing in the BMJ journal the researchers concluded: “Adding pump treatment to structured training in flexible intensive insulin treatment did not substantially enhance educational benefits on glycaemic control, hypoglycaemia, or psychosocial outcomes in adults with type 1 diabetes.”
The Relative Effectiveness of Pumps Over MDI and Structured Education (REPOSE) randomised controlled trial included 317 adults with type 1 diabetes.
All participants were first placed on the Dose Adjustment for Normal Eating (DAFNE) one-week training course which showed them how to adjust their insulin dose based on estimated carbohydrate intake.
They were then randomly allocated to insulin pump or multiple daily injections for two years if their HbA1c values were 7.5 per cent (59mmol/mol) or higher after the education.
About a quarter either did not attend classes or had HbA1c values lower than this threshold and this left 235 people for the analyses (119 pump users and 116 in the injections group).
The findings showed blood glucose control improved in all participants, with no statistically significant difference between groups. The mean reduction in HbA1c was 0.85 per cent with pump treatment and 0.42 per cent with injections (odds ratio 1.22, 95 per cent confidence interval 0.62 to 2.39). Only one in four participants achieved the NICE 2004 target for HbA1c of 7.5 per cent (58mmol/mol) or less by two years (25.0 per cent for the pump group and 23.3 per cent for the injections group).
There was no difference between groups in the number of severe low blood glucose (hypoglycaemic) episodes. The average number of episodes per person, per year reduced from 0.17 at the beginning of the study to 0.10 at the end of the study.
Insulin pump failure
More people in the pump group suffered from diabetic ketoacidosis, most often due to infection (17 events compared to five events in the injection group). Nearly one in five episodes of ketoacidosis were said to be due to insulin pump failure.
Various generic and diabetes specific quality of life measures showed little difference between groups. Pump users reported higher scores in some domains, for example, treatment satisfaction, improved dietary freedom and reduced daily hassle.
While both groups saw improvements in blood glucose levels and fewer hypoglycaemic episodes (very low blood sugar) over two years, only one in four participants met NICE blood glucose targets. Insulin pump users showed some modest improvements in satisfaction, dietary freedom and daily hassle.
Professor of diabetes medicine at Swansea University Steve Bain gave his opinion on the findings. He said: “Diabetes services are often judged according to how many patients are being treated with insulin pump therapy. The assumption has always been that this more expensive system of insulin delivery is the gold standard and the higher the proportion being treated with a pump, the better the service. This study suggests that it is the standard of education that is important, rather than the technology.
“Furthermore, it shows that even with the best education and technology, the glycaemic targets routinely advocated by the National Institute for Health and Care Excellence for people with type 1 diabetes are impossible to achieve.”
Dr Mujahid Saeed, consultant physician in diabetes at the Queen Elizabeth Hospital Birmingham, said: “Sub-cutaneous insulin infusion pump therapy can be a useful way of managing diabetes in some of these people; however, it comes at a premium in comparison to the use of multiple daily insulin injections in a cash-stripped NHS. This randomised controlled study affirms some of my own impressions when I am seeing patients in my weekly type 1 diabetes clinic.
“Structured patient education remains a key priority. Where limitations remain in optimising care in a motivated and actively engaging patient, one should consider pump therapy. Further studies in this area are warranted.”
Although participants in both groups showed sustained improvement, blood glucose control remained far short of targets currently recommended by NICE. Only 3 per cent of all participants reached an HbA1c of 6.5 per cent (48mmol/mol) or less. People with type 1 diabetes might be better served by ensuring greater availability of high quality, structured self-management training, which is currently only accessed by around 10 per cent of adults in the UK.
Simply increasing use of insulin pumps may increase resource costs without seeing improvements to diabetes control. If after training individuals still find blood glucose control challenging, they could be offered pump treatment in line with NICE guidance to see if this improves quality of life.