Use of an artificial pancreas is associated with better control of blood sugar levels for people with type 1 diabetes compared with standard treatment, finds a review of the available evidence. The findings show that artificial pancreas treatment provides almost two and a half extra hours of normal blood glucose levels (normoglycaemia) a day, while reducing time in both high (hyperglycaemia) and low (hypoglycaemia) blood glucose levels.
While further research is needed to verify the findings, the researchers say these results support the view that “artificial pancreas systems are a safe and effective treatment approach for people with type 1 diabetes.”
The artificial pancreas is a system that measures blood sugar levels using a continuous glucose monitor (CGM) and transmits this information to an insulin pump that calculates and releases the required amount of insulin into the body, just as the pancreas does in people without diabetes.
Lead researcher, Eleni Bekiari at Aristotle University of Thessaloniki, Greece and Harris Manchester College, University of Oxford and the team set out to investigate the effectiveness and safety of artificial pancreas systems in people with type 1 diabetes. They reviewed the results of 41 randomised controlled trials involving over 1000 people with type 1 diabetes, that compared artificial pancreas systems with other types of insulin-based treatment, including insulin pump therapy.
They found that the artificial pancreas was associated with almost two and a half additional hours in normo-glycaemia compared with other types of treatment when used overnight and over a 24-hour period. Use of the artificial pancreas also reduced time spent in hyperglycaemia by approximately two hours – and in hypoglycaemia (20 minutes less) – compared to other types of therapy.
Further analyses to test the strength of the associations for different devices and in different settings were consistent, suggesting that the results are robust.
As such, the authors say that their review provides a valid and up to date overview on the use of artificial pancreas systems for type 1 diabetes. However, they point out that most trials were at high or unclear risk of bias, had a small sample size and short duration, and therefore should be interpreted with caution. Furthermore, they suggest more should be done to assess cost-effectiveness “to support adoption of artificial pancreas systems in clinical practice.”
The authors also recommend that future research should “explore artificial pancreas use in relevant groups of people with type 2 diabetes” and say “the effect of artificial pancreas use on quality of life and on reducing patient burden should be further explored.”
In a linked editorial, Professor Norman Waugh at the University of Warwick and colleagues, argue that closed loop systems have much to offer, “but we need better evidence to convince policymakers faced with increasing demands and scarce resources.”
Objective: To evaluate the efficacy and safety of artificial pancreas treatment in non-pregnant outpatients with type 1 diabetes.
Design: Systematic review and meta-analysis of randomised controlled trials.
Data sources: Medline, Embase, Cochrane Library, and grey literature up to 2 February 2018.
Eligibility criteria for selecting studies: Randomised controlled trials in non-pregnant outpatients with type 1 diabetes that compared the use of any artificial pancreas system with any type of insulin based treatment. Primary outcome was proportion (%) of time that sensor glucose level was within the near normoglycaemic range (3.9-10 mmol/L). Secondary outcomes included proportion (%) of time that sensor glucose level was above 10 mmol/L or below 3.9 mmol/L, low blood glucose index overnight, mean sensor glucose level, total daily insulin needs, and glycated haemoglobin. The Cochrane Collaboration risk of bias tool was used to assess study quality.
Results: 40 studies (1027 participants with data for 44 comparisons) were included in the meta-analysis. 35 comparisons assessed a single hormone artificial pancreas system, whereas nine comparisons assessed a dual hormone system. Only nine studies were at low risk of bias. Proportion of time in the near normoglycaemic range (3.9-10.0 mmol/L) was significantly higher with artificial pancreas use, both overnight (weighted mean difference 15.15%, 95% confidence interval 12.21% to 18.09%) and over a 24 hour period (9.62%, 7.54% to 11.7%). Artificial pancreas systems had a favourable effect on the proportion of time with sensor glucose level above 10 mmol/L (−8.52%, −11.14% to −5.9%) or below 3.9 mmol/L (−1.49%, −1.86% to −1.11%) over 24 hours, compared with control treatment. Robustness of findings for the primary outcome was verified in sensitivity analyses, by including only trials at low risk of bias (11.64%, 9.1% to 14.18%) or trials under unsupervised, normal living conditions (10.42%, 8.63% to 12.2%). Results were consistent in a subgroup analysis both for single hormone and dual hormone artificial pancreas systems.
Conclusions: Artificial pancreas systems are an efficacious and safe approach for treating outpatients with type 1 diabetes. The main limitations of current research evidence on artificial pancreas systems are related to inconsistency in outcome reporting, small sample size, and short follow-up duration of individual trials.
Eleni Bekiari, Konstantinos Kitsios, Hood Thabit, Martin Tauschmann, Eleni Athanasiadou, Thomas Karagiannis, Anna-Bettina Haidich, Roman Hovorka, Apostolos Tsapas