Which diabetes management methods maximize glucose control for patients with type 1 diabetes?

This analysis compared diabetes treatments for how much of the time blood sugar is in the target range. It found that closed-loop systems, which combine a continuous glucose monitor (CGM) and insulin pump, led to better outcomes for people with type 1 diabetes (T1D).

T1D is a disorder in which the body cannot produce the hormone insulin, which controls the amount of glucose (sugar) in the blood. People with T1D require artificial insulin to maintain stable blood glucose. 

The most common method to monitor blood glucose is using finger stick tests throughout the day and after meals. This can be combined with a daily long-acting insulin injection and short-acting insulin injections around meals. However, this routine requires effort throughout the day and the regular use of needles.

There are several devices which may simplify diabetes management. CGM uses a probe inserted under the skin to test glucose levels all day long, without the need for finger sticks. An insulin pump is another diabetes management tool which uses a port under the skin to deliver insulin. Insulin pumps can be programmed to release insulin at certain hours and can be adjusted by the user. A closed-loop system uses software to automatically control an insulin pump using the data from a CGM.

It is not clear which method of diabetes management leads to the best glucose control in patients with T1D.

This review included 14 studies with 1,043 patients with T1D. All of the studies continuously monitored glucose levels for at least two weeks. The studies included eight diabetes management methods. These included finger sticks or CGM paired with daily injections or an insulin pump. It also included a closed-loop system, either all day or only at night. Each study compared two treatments. Statistical methods were used to compare the results of different trials.

Closed-loop systems led to more time when blood glucose was in the target range (3.9 to 10.0 mmol/L) than any other method. Closed-loop systems increased the time in the target range by 17.85% compared to finger sticks with multiple injections. Compared to CGM with insulin pumps, closed-loop systems increased the time in range by 8.77%. 

Compared to finger stick tests with daily injections, using a CGM with daily injections increased the time in range by 5.09%.

This study found that closed-loop systems led to better blood glucose control than other diabetes management methods.