'Artificial pancreas' shows promise in Boston experiments

For people with type 1 diabetes, keeping their condition in control is a constant process of testing their blood sugar levels and adjusting how much insulin they need based on what they eat and how active they are. Because their pancreases no longer produce insulin, which ferries blood sugar into cells, they must inject the hormone several times a day or wear a pump that infuses preset amounts into their bodies, adding more around meals. If blood sugar falls too low, they risk falling into a coma. But if blood sugar levels are too high for too long, serious complications such as kidney damage, limb amputation, and blindness can occur over a lifetime. 

A team of Boston researchers report today in the journal Science Translational Medicine on two experiments with an "artificial pancreas," a system that continuously monitors blood sugar and directs infusion of both insulin and glucagon, a hormone that raises blood sugar, via pump, adjusting the doses in response to absorption rates and other variations. The study was small, involving 11 people who spent 27 hours in hospital beds tethered to intravenous lines and monitored by a program running on a laptop. But the team from Boston University and Massachusetts General Hospital hopes to replace the laptop with a computer chip that would be part of the pump, a glucose monitor that works with a thin wire under the skin, and a dual pump that together would mimic what the healthy pancreas does minute by minute.

Over the 27 hours, the adult study subjects averaged blood sugar levels within the target range, although in the first experiment five of them occasionally had levels sink low enough that they needed to drink orange juice to bring them back up. After the researchers determined that the patients were absorbing insulin at widely different rates, they adjusted the computer algorithm and succeeded at keeping blood sugar levels where they should be, without dips into hypoglycemia, senior author Edward Damiano of BU said in an interview.

In a commentary also appearing in the journal, Larry Brown  and Dr. Elazer Edelman of the Harvard MIT Division of Health Sciences and Technology
ask whether such systems can help answer questions about diabetes, including whether other hormones in addition to glucagon should be considered in an artificial pancreas.

Damiano, whose 11-year-old son was diagnosed with type 1 diabetes when he was 1 year old, has set himself a deadline for making therapy better for diabetics while waiting for a cure. "My son's going to be entering college in seven years. That's my window."