Use of insulin pumps is associated with much lower risks of cardiovascular deaths, as well as deaths from other causes, compared with use of insulin pens.
The study carried out by researchers at the University of Gothenburg enrolled over 18,168 patients with type 1 diabetes from the Swedish National Diabetes Register. Of these patients, 15,727 used insulin pens on a multiple daily injection therapy and the other 2,441 patients used insulin pumps.
The participants were reviewed over a period of 7 years and rates of cardiovascular disease (heart disease) and death were analysed. The findings showed that users of insulin pumps, when compared to the users of insulin pens, were:
43% less likely to die from cardiovascular disease
29% less likely to die from any cause
18% less likely to develop either fatal or non-fatal cardiovascular disease
The researchers note that there were differences between the groups of insulin pump users and insulin pen users. For instance, users of insulin pumps were generally slightly younger, had shorter durations of diabetes, lower blood pressure and better levels of education. Whilst propensity-scoring was used to balance differences between the two groups, the researchers noted that other confounding factors may not have been accounted for. HbA1c was balanced between the two groups within the analysis.
There are a number of reasons directly related to insulin pump usage that may explain the lower risks of heart disease in the insulin pump users. Previous research has shown that users of insulin pumps tend to have lower daily doses of insulin which may explain the lower rates of blood pressure and heart disease.
Another factor that could explain some of the differences is if the users of insulin pumps experienced lower variability in blood glucose results. Previous research has shown that wide swings in blood glucose results to be linked with increased heart risks in people with type 1 diabetes.
The research will be of interest to people with type 1 diabetes that are considering going onto insulin pump therapy. Currently, within the UK, insulin pump treatment (also known as continuous subcutaneous insulin infusion or CSII) is estimated to be used by 6% of adults with type 1 diabetes and 19% of children with the condition. The research showing decreased rates of deaths raises another good reason for the UK to widen its access to insulin pump therapy.