Bionic pancreas improves glycated haemoglobin level in type 1 diabetics

11th October 2022

A bionic pancreas that automatically delivers insulin gave better control of glycated haemoglobin compared to standard care in a recent RCT

A bionic pancreas can provide better control of glycated haemoglobin levels compared to standard care according to the findings of a randomised trial by a team of US researchers.

The term ‘diabetes’ refers to a group of diseases characterised by high blood glucose levels that occur due to a deficiency in the production or function of insulin or both. Type 1 diabetes is the main form diagnosed in childhood and characterised by increased blood glucose levels resulting from insulin deficiency. It is relatively common and in a 2020 study, it was estimated that globally, the incidence of type 1 diabetes was 15 per 100,000 and had a prevalence of 9.5%.

Multiple studies have confirmed that a higher glycated haemoglobin (HbA_1c) level is an independent risk factor for diabetes complications. As a result, according to a consensus report in 2021 by the American Diabetes Association and the European Association for the Study of Diabetes, a HbA_1c goal for most adults of <53 mmol/mol (<7.0%) without significant hypoglycaemia is appropriate. Nevertheless, in a US real-world study of 31,430 type 1 patients, only around 20% had a HbA_1c of < 7%.

Currently, hybrid closed-loop insulin-delivery systems are able to partially automate insulin delivery and have shown improved glycaemic control in adults and youth with type 1 diabetes by reducing both hyperglycaemia and hypoglycaemia. Another innovation is a bionic pancreas, which represents an automated insulin delivery system initialised only with body weight and without any information about previous insulin dosing. A bionic pancreas works together with a continuous sugar monitoring (CGM) tool to autonomously deliver insulin and/or glucagon to control an individual’s blood glucose level in response to their real-time sensor glucose readings from the CGM.

In the present study, US researchers undertook a randomised trial to compare a bionic pancreas which provided either aspart or insulin lispro with standard care in terms of managing glycated haemoglobin levels. For the study, standard care was defined as any insulin-delivery method with unblinded, real-time continuous glucose monitoring. Individuals aged 6 years and older who were diagnosed with type 1 diabetes and using insulin for at least 12 months, were randomised 2:1 to the bionic pancreas (with insulin aspart or lispro) or standard care. The primary outcome was the glycated haemoglobin level at 13 weeks, whereas secondary outcomes included the percentage time that glucose levels were below 3 mmol/L and the percentage of time that glucose levels remained in the target range of 3.9 to 10 mmol/L.

Bionic pancreas and glycated haemoglobin

A total of 326 adults and children with a mean age of 28 years (49% female in the bionic group) were included in the analysis.

The mean glycated haemoglobin level was 7.3% (down from a baseline of 7.9%) in the bionic group but remained unchanged at 7.7% in the standard care group (mean adjusted difference = -0.5, 95% CI -0.60 to – 0.30, p < 0.001).

However, the percentage of time with glucose levels below 3 mmol/L was not significantly different. In contrast, both the mean glucose level and the percentage time spend in the target range of 3.9 to 10 mmol/L were both statistically significant, favouring the bionic pancreas. In fact, based on the percentage time within the target range, the researchers calculated that the difference of 11% equated to an increase of 2.6 hours/day for the bionic group.

The rate of severe hypoglycaemia was 17.7 events per 100 participant-years in the bionic group and 10.8 events for the standard care group which was non-significant (p = 0.39).

The authors concluded that the bionic pancreas was associated with a greater reduction in glycated haemoglobin compared to standard care.

Citation
Bionic Pancreas Research Group. Multicenter, Randomized Trial of a Bionic Pancreas in Type 1 Diabetes N Eng J Med 2022

Combing glargine or liraglutide and metformin best for glycated haemoglobin target

3rd October 2022

Glargine or liraglutide with metformin were the most effective agents for achieving a glycated haemoglobin target in type 2 diabetics

Combining glargine or liraglutide with metformin is significantly, albeit modestly, more effective at maintaining a glycated haemoglobin target than either glimepiride or sitagliptin according to the findings of a 5-year study by the GRADE Study Research Group.

Data from 2017 suggest that approximately 462 million individuals were affected by type 2 diabetes (6.28% of the world’s population) and with over 1 million annual deaths attributable to the condition, making it the ninth leading cause of mortality.

The fact that improved blood-glucose control decreases the progression of diabetic microvascular disease as been known for many years and can be assessed using the level of glycated haemoglobin (HbA1c). In a recent meta-analysis it was concluded that the optimal HbA1c range for type 2 diabetes is 7.1-7.7% regardless of diabetes duration.

Moreover, the European Society of Cardiology Guidelines have suggested that glucose control to target a near-normal HbA1c (<7.0% or <53 mmol/mol) will decrease the frequency and severity of microvascular complications in patients with diabetes. Metformin is a recommended by the guidelines as a first-choice treatment in overweight patients with type 2 diabetes and without cardiovascular disease and in those at moderate cardiovascular risk.

However, if this fails to provide adequate diabetic control, there is a lack of clarity over which second treatment should be added to achieve control. This was the purpose of the GRADE study and designed to inform decisions about the clinical effectiveness of addition of four classes of diabetes medications to metformin.

Patients with type 2 diabetes were given metformin and during a 6 to 14 week run-in period, the dose of the drug was increased to at least 1000 mg daily but with a target dose of 2000 mg daily. Four medications could be added to metformin to maintain disease control: insulin glargine; glimepiride; liraglutide or sitagliptin and participants were randomised to one of these four treatments in addition to metformin.

The primary metabolic outcome was a metabolic failure, defined as a glycated haemoglobin of 7% or higher.

Glargine and diabetic control

A total of 5047 participants with a mean age of 57.2 years (63.6% male) and a mean body mass index of 34.3 were included in the study. Across the whole cohort, the mean duration of diabetes was 4.2 years and participants were followed for 5 years.

Over the 5-year follow-up period, 71% of the cohort had a primary metabolic outcome event, i.e., did not achieve the target glycated haemoglobin level of less than 7%. This was highest for those taking sitagliptin (77.4%), followed by glimepiride (72.4%), liraglutide (68.2%) and lowest for glargine (67.4%).

Using a global test of differences across groups, this finding was significant (p < 0.001). However, when comparing the rate/100 participant-years, the values for each of the drugs were broadly similar, ranging from 26.5% (glargine) to 38.1% (sitagliptin).

In pairwise comparisons, the risk of the primary outcome was significantly lower with glargine than with sitagliptin (hazard ratio, HR = 0.71, 95% CI 0.64 – 0.78, p < 0.001). It was also lower for liraglutide compared with sitagliptin (HR = 0.69, 95% CI 0.63 – 0.76, p < 0.001).

The authors concluded that while all four treatments when added to metformin improved glycated haemoglobin, glargine and liraglutide were significantly, though modestly, more effective at achieving and maintaining target levels.

Citation
The GRADE Study Research Group. Glycemia Reduction in Type 2 Diabetes — Glycemic Outcomes N Engl J Med 2022