CGM use drives better type 1 diabetes treatment in people on multiple daily injections

Previous research has shown better diabetes outcomes when using continuous glucose monitoring (CGM) in conjunction with insulin pumps in type 1 diabetes, but data was lacking among people with different treatment strategies.
Two randomised controlled trials, recently published in the journal JAMA, now suggest that CGM can also greatly benefit people with type 1 diabetes who use multiple daily insulin injections.
CGM actually start to trump other diabetes devices commonly used in combination with them, which is why the FDA recently announced that certain CGM devices could therefore soon be classified as durable medical equipment (DME).
This means that they would no longer be regarded as precautionary. They could be used directly for making diabetes treatment decisions, instead of just alerting someone to use a blood glucose monitor to make those decisions.
Findings from the new randomised controlled trials here seem to support this decision for people with type 1 diabetes using multiple daily injections. These show that within this population, CGM improves HbA1c levels more so than conventional treatment.
In one study, researchers from the Jaeb Centre for Health Research followed 158 adults with type 1 diabetes on multiple daily injections who had HbA1c levels between 58.5 mmol/mol and 84.7 mmol/mol. About a hundred of them were assigned to CGM while 53 of them remained under usual care to bring those levels down to 53 mmol/mol.
Results showed that the average HbA1c reduction from baseline was 1.1 percent at 12 weeks and 1.0 percent at 24 weeks in the CGM group. In the control group, HbA1c levels dropped by 0.5 percent and 0.4 percent, respectively.
The CGM also appears to aid in detection of episodes of hypoglycemia, with a median duration of hypoglycemia equivalent to 43 minutes a day in the CGM group, compared to 80 minutes a day in the control group. Severe hypoglycemia events however still occurred in two participants in each group.
The second study, conducted at the University of Gothenburg, looked at HbA1c reductions after 26 weeks in 161 participants with slightly more elevated HbA1c levels and using either CGM or conventional treatment with a washout period in-between.
The researchers found that the mean difference in HbA1c was 0.43% (4.7 mmol/mol). The treatment with CGM was also superior in limiting hypoglycemia events. Five patients in the control group had severe hypoglycemia, while just one patient in the CGM group suffered from it.
This second study also measured the impact of CGM on glucose patterns, and found that glucose variability was reduced by CGM, helping to flatten out extremes blood sugar fluctuations. The CGM group spent 52 fewer minutes a day outside the 3.9 mmol/mol to 10 mmol/mol target range, as well as less time with glucose levels above and below the target range.
Taken together, these two studies show that the use of CGM result in a modest, but nonetheless greater decrease in HbA1c after about 6 weeks.
Longer-term studies are now needed to determine the effect of CGM on other variables, such as whether it helped people understand how habits affect glucose levels and work towards optimising their insulin management.