Real-time CGM lowers HbA1c and reduces emergency room visits in insulin-treated diabetes

Insulin-treated adults with diabetes selected by clinicians for continuous real-time blood glucose monitoring saw a 0.4 percentage point reduction in HbA1c and less Emergency room visits for hypoglycemia for 1 year of follow-up against non-users.

“Our real-world study found that in diabetic patients treated with insulin, starting a continuous blood glucose monitor significantly improved blood sugar control and halved the rate of emergency room visits for hypoglycemia.” , he added. Andrew J. Karter, PhD, principal investigator at the Kaiser Permanente research division in Oakland, Calif., Healio said. “Because the use of these devices requires a prescription, the observed benefits suggest that physicians are good at selecting patients who may benefit from the use of a continuous glucose monitor. As these doctors know, insulin-treated patients often have a hard time lowering their blood sugar levels safely to meet their goals, and these monitors can help people stay close to their blood sugar goals without falling too low.

Most of the evidence for the effectiveness of CGM has been based on randomized controlled trials in adults with type 1 diabetes, and there have been fewer trials of effectiveness of real-time CGM in adults with type 2 diabetes treated with insulin, says Karter. Medicare covers CGM for insulin-treated type 2 diabetes patients who meet certain criteria, but the technology is not yet considered the standard of care, he said.

“We evaluated the initiation of CGM in patients with type 1 diabetes or type 2 diabetes treated with insulin in the real-life setting of Kaiser Permanente Northern California and found that they had improved control of blood sugar levels and reduced the number of emergency room visits due to hypoglycemia, ”Karter said.

Introduction to CGM in the real world

In a retrospective study, Karter and colleagues analyzed data from 41,753 insulin-treated adults with diabetes (5,673 type 1; 36,080 type 2) receiving care from an integrated health care delivery system. from northern California from 2014 to 2019. Within the cohort, 3,806 adults initiated CGM (mean age, 42 years; 51% female; 91% with type 1 diabetes) and 37,947 were non-initiators ( reference group; mean age, 63 years; 49% women; 6% with type 1 diabetes).

The researchers measured 10 parameters measured during the 12 months before and 12 months after baseline: HbA1c; hypoglycemia (emergency or hospital use); hyperglycemia (emergency or hospital use); HbA1c levels below 7%, below 8% and above 9%; one or more meetings in the emergency room for any reason whatsoever; one or more hospitalizations for any reason whatsoever; and the number of outpatient and telephone visits.

Reduced HbA1c, fewer emergency room visits

The mean pre-baseline HbA1c was lower in real-time CGM initiators than in non-initiators, but real-time CGM initiators had higher rates of pre-baseline hypoglycemia and hyperglycemia.

The researchers found that the mean HbA1c decreased in real-time CGM initiators from 8.17% to 7.76% and from 8.28% to 8.19% in non-initiators, for an adjusted estimate of the difference in differences of 0.4% (95% CI, 0.48 to 0.32).

Hypoglycemia rates decreased in initiators of real-time CMS from 5.1% to 3% and increased in non-initiators from 1.9% to 2.3%, for an estimate of the difference in differences 2.7% (95% CI, 4.4 to 1.1). There were also statistically significant increases in the proportion of patients with HbA1c less than 7% (adjusted estimate for differences in differences, 9.6%; 95% CI, 7.1-12.2); higher proportion of HbA1c less than 8% (adjusted estimate for differences in differences, 13.1%; 95% CI: 10.2-16.1); fewer patients with HbA1c greater than 9% (adjusted estimate for differences in differences, 7.1%; 95% CI, 9.5 to 4.6); fewer outpatient visits (adjusted difference-indifference estimate, 0.4; 95% CI, 0.6 to 0.2); but more telephone visits (adjusted estimate for differences in differences, 1.1; 95% CI, 0.8-1.4).

Initiation of real-time CGM was not associated with statistically significant changes in hyperglycemia rates, emergency room visits for any reason, or hospitalizations for any reason.

“Based on the evidence from clinical trials, we expected that the implementation of continuous glucose monitors would improve blood sugar control and reduce hypoglycemia in patients with type 1 diabetes. However, we have was surprised to find that these clinical benefits were even greater in patients with type 2 diabetes, ”Karter told Healio. “We were also surprised that our observed efficacy results were stronger than the efficacy reported in most randomized trials. In addition, it appeared that physicians preferred to prescribe monitors to high-risk patients for emergency room visits for hypoglycemia, while glycemic control appeared to have less influence on prescribing patterns.

Karter said the results show that initiation of CGM resulted in improvements in blood sugar response comparable to what a patient might experience after starting a new diabetes drug.

“However, drugs to improve blood sugar control may increase the risk of hypoglycemia, while CGM may improve blood sugar control while reducing the risk of hypoglycemia,” Karter told Healio. “CGMs are widely used in type 1 patients. However, its use is currently minimal in patients with type 2 diabetes treated with insulin; our study suggests that this technology could benefit other patients in this high-risk group.