Insulin pumps show better diabetes control in teenagers

A study of over 700 children with type 1 diabetes appears to show that insulin pump therapy significantly improves blood glucose control through teenage years.
The study, carried out by researchers at the Princess Margaret Hospital for Children, in Perth, Australia followed the children’s progress over 7 years. 355 patients were on insulin pumps and 355 patients on injections; split between multiple daily injections and twice daily injections.
From the start of pump use up to 7 years after, the pump group had better HbA1c levels than the group that stayed on injection therapy.
The difference between the groups widened through adolescence as teenagers in the injections group saw their HbA1c rise significantly. For the injections group, HbA1c values which started at 64 mmol/mol (8.0%) grew steadily to 73 mmol/mol (8.8%) after 7 years. The pump group also started with an HbA1c of 64 mmol/mol (8.0%) but this actually decreased to 61 mmol/mol (7.7%).
Parents of teenagers with diabetes will be interested to note that in the injections group, HbA1c gradually grew throughout teenage years, whereas within the insulin pumps group, HbA1c changed differently. Pump users started off with a significant drop in HbA1c, down to 60 mmol/mol (7.6%), 3 months after commencing pump therapy. This was then followed by a gradual increase up to 65 mmol/mol (8.1%) 2 years after commencing pump use. Following this peak at the 2 year mark, HbA1c started to gradually but steadily come back down, culminating with 61 mmol/mol (7.7%) after 7 years of pump usage when the average of the group was 18.
It is worth noting that whilst both groups started the study with the same average HbA1c, those in the insulin pump group had displayed a slightly better ability to control their blood glucose 1 year prior to the start of pump use. This could indicate that these patients were therefore slightly better equipped to manage their diabetes than those in the injections group.
It is very much up to interpretation of why HbA1c got worse during teenage years for those on injection and slightly better for insulin pump users. A significant factor may be that those on a pump are essentially tied to their therapy.
It is well established that teenagers and young adults with type 1 diabetes have particular difficulty in controlling blood glucose levels and that missing out injections and blood glucose tests is relatively common among this age group. With insulin pump usage, missing doses is less of an issue, particularly as the pump delivers a steady basal rate. This also means that teenagers know it is also important to regularly carry out blood tests to prevent short term complications.
Another strong benefit of insulin pump therapy highlighted by the study is that the rate of severe hypos was also significantly lower, 30% lower, over the course of the 7 years follow up amongst the pump users.
Those on injections had 10.2 episodes of severe hypoglycemia per 100 patient years compared with 7.2 episodes of severe hypo per 100 patient years within the insulin pump group.
The study, “Long-term outcome of insulin pump therapy in children with type 1 diabetes assessed in a large population-based case control study” appears in the research journal Diabetologia.