CGM Offers Confidence Boost for Those Managing Diabetes With Insulin Injections, Study Finds

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The researchers' hypothesis: improvements in continuous glucose monitoring technology would bring greater quality of life improvements for those with type 1 diabetes, even if they were not using insulin pumps.

As continuous glucose monitoring (CGM) technology improves, patients with type 1 diabetes (T1D) using insulin injections gain not just an absence of fear about hypoglycemia, but increased confidence that they know what to expect, according to new results reported in Diabetes Care.

CGM technology is more than a decade old, and even proponents admit its earliest incarnations weren’t always reliable and demanded a lot of effort from patients. But as CGM has become less cumbersome and more reliable, adoption has become more widespread.

Earlier this year, the DIAMOND randomized clinical trial reported results that showed CGM could produce improved glycemic control in patients using the technology with multiple daily injections, not just an insulin pump. The latest results from DIAMOND report quality of life results from the same group of 158 patients, who all administered insulin by injection and were randomized 2:1 for CGM or self-monitored blood glucose (SMBG).

Improvements in CGM accounted for a key element of DIAMOND, which studied the Dexcom G4: “We hypothesized that this newer generation of CGM leads to greater improvements in (quality of life) markers, especially in diabetes-specific measures (which are known to be more sensitive to change than non-diabetes-specific measures), than what occurs in individuals who use SMBG alone.”


Researchers looked at 2 sets of quality of life measures: those not specific to diabetes, which included the World Health Organization 5 Well-Being Index and the EQ-5D-5L; and those specific to diabetes, this Diabetes Distress Scale, the Hypoglycemia Fear Survey, and the Hypoglycemia Confidence Scale.

Researchers found that compared with the SMBG group, patients using CGM had statistically significant improvements in diabetes-related quality of life measures, especially reductions in diabetes distress and increases in hypoglycemic confidence. Of note, these benefits were consistent across subgroups and not limited to those with low confidence or high diabetes distress at baseline.

Lead author William H. Polonsky, PhD, associate clinical professor in Psychiatry at the University of California at San Diego, explained in an interview with The American Journal of Managed Care® why it’s significant that CGM offers benefits beyond reducing fear. “Especially with type 1 diabetes, the issue isn’t just being frightened about a hypo—it’s about being able to trust your body,” he said. “Can I be safe driving a car? Can I sleep at night?”

Confidence, he said, needs to stand alone as an additional factor, and this study shows that CGM can increase confidence for those who manage their disease with multiple daily injections.

Polonsky said that while the DIAMOND study did not measure sleep, he acknowledged the growing body of evidence connecting disturbed sleep and insulin resistance. Technology that would give people with T1D the confidence to get a good night’s sleep on a regular basis would seem to be good for their health.

A limitation of DIAMOND was that the patients were followed for 24 weeks, so that the long-term psychosocial benefits could not be reported for this study. Polonsky said a subset of the patients in DIAMOND were followed for a longer period, and those results will be reported shortly.

Evaluating CGM satisfaction comes down to balancing its benefits against its hassles, Polonsky said, which is what researchers did in the study. The good news, he said, is that CGM is about to become much more exciting, with players like Google and Apple joining the market. CGM products will become less cumbersome, more intuitive, hassle-free, and cheaper.

Polonsky foresees CGM becoming a more routine part of care for people with type 2 diabetes, if not full-time, then for brief episodes to give them a snapshot of how their food intake and habits affect their blood glucose levels.

“It’s a cool time for our patients,” he said.


Polonsky WH, Hessler D, Ruedy KJ, Beck RW, for the DIAMOND Study Group. The impact of continuous glucose monitoring on markers of quality of life in adults with type 1 diabetes: findings from the DIAMOND randomized clinical trial. Diabetes Care. 2017; 40(6): 736-741.