Dual-hormone artificial pancreas beats insulin-alone system in glycaemic control in small study
“Post-meal [glycaemic] control remains a challenge [with insulin-only artificial pancreas] … This study shows that the first-generation, insulin-only artificial pancreas can be improved by delivering other hormones along with insulin, which will hopefully encourage the development of insulin-plus-pramlintide coformulations,” said lead author Dr Ahmad Haidar of McGill University in Montreal, Canada.
Pramlintide is a synthetic analogue of amylin — a hormone that helps regulate blood glucose levels but is completely absent in people with T1D. Besides insulin analogues, pramlintide represents the only FDA-approved drug known to reduce blood glucose levels in T1D patients.
In the crossover study, twelve adults (mean age 43 years) with T1D were randomized to any one of the three systems: a DAP delivering rapid insulin and pramlintide, DAP delivering regular insulin (Humulin R) and amylin (DAP-R), and a rapid insulin-alone artificial pancreas for 24 hours before crossing over to another system for another 24 hours. During each 24-hour period, the participants had three meals plus one bedtime snack. [ADA 2018, 210-OR]
Compared with the insulin-alone system, DAP significantly improved the duration of time spent in target range of 3.9–10.0 mmol/L, from 71 percent to 85 percent of the 24-hour study period (p=0.03).
There was also less glucose variability with DAP vs the insulin-alone system (25 percent vs 34 percent; p=0.01), without an increased risk of hypoglycaemia.
Furthermore, mean glucose level during daytime was lower with DAP than the insulin-alone system (7.8 vs 9.1 mmol/L; p=0.02).
In terms of adverse events, two participants using DAP reported moderate nausea while none were reported while using the insulin-alone system.
“We were expecting some benefits with the insulin-plus-pramlintide artificial pancreas, yet we were impressed by both the extent of improvements and the lack of side effects, considering these benefits were achieved without increasing the risk of dangerous low-glucose levels,” said Haidar.
Time spent in target range during overnight period was similar between the DAP and the insulin-alone groups (77 percent vs 71 percent; p=0.47).
On the other hand, the DAP-R system did not confer additional benefits over the insulin-alone system during the daytime or overnight study periods.
“Longer and larger studies in free-living outpatient settings are warranted,” said Haidar, who noted the small number of study subjects in the current comparison.