Continuous Glucose Monitoring Can Help Anyone with Diabetes   (November 30, 2011)

"Long-term use of continuous glucose monitoring devices is considered experimental and investigational for all other indications." That's what one major insurance company says about CGM -- unless  it's deemed "medically necessary as an adjunct to fingerstick testing of blood glucose in adults age 25 years and older with type 1 diabetes, and for younger persons with type 1 diabetes who have had recurrent episodes of severe hypoglycemia (defined as hypoglycemia (blood glucose less than 50 mg/dL) with unawareness that required assistance from another person to administer oral carbohydrate, glucagon, or other resuscitative actions) despite appropriate modifications in insulin regimen and compliance with frequent self-monitoring (at least 4 fingersticks/day)."

Astonishing. Women with diabetes who are pregnant and on insulin, and anyone with Latent Autoimmune Diabetes who's on appropriate treatment with insulin, and insulin-treated patients with Type 2 aren't at high enough risk to keep the insurance bureaucrats satisfied? Such patients are all at risk of recurrent episodes of severe hypoglycemia, just as are folks with type 1 diabetes, and the idiocy of excluding them from using CGM is counterproductive - one severe reaction and the cost of hospitalization would be more than the cost of CGM by far!

Of course, someone has to produce the evidence that use of long-term use of CGM is indeed helpful, and one of the manufacturers of CGM devices has just done so. In a recent study published in Diabetes Care, Short- and Long-Term Effects of Real-Time Continuous Glucose Monitoring in Patients With Type 2 Diabetes, CGM was found to be effective in improving blood glucose control in people with type 2 diabetes. The authors studied  100 adults with type 2 diabetes who were on a variety of medication programs, but were not on mealtime insulin. Some participants were randomized to using CGM for three months, in four cycles (two weeks on, one week off); the other study subjects performed pre-meal/bedtime self-monitoring of blood glucose levels (SMBG). The CGM devices were then removed and all the patients were observed for nine more months.

There was no specific training offered to participants on how to respond to the CGM data.

The results are astonishing, even to me, who strongly believes in feedback from glucose monitoring as an effective way to change behavior. "There was a significant difference in A1C at the end of the 3-month active intervention that was sustained during the follow-up period. The mean, unadjusted A1C decreased by 1.0, 1.2, 0.8, and 0.8% in the RT-CGM group vs. 0.5, 0.5, 0.5, and 0.2% in the SMBG group at 12, 24, 38, and 52 weeks, respectively." The subjects who used CGM as the protocol was written (for 48 days or more) improved the most. And most important, the improvement in the CGM group occurred without a greater intensification of medication compared with those in the SMBG group.

The lead author speculated "that real-time, continuous blood sugar monitoring gave patients an increased awareness of the glycemic changes in their bodies, in response to what they ate, drank and when they exercised...   [and] as a result of their increased awareness, participants may have made healthy lifestyle decisions and adhered to their medication regime."

Seems very reasonable to me: CGM works as a tool to help people with diabetes to assess their blood sugar levels, and to subsequently modify their behavior. Lowering of A1C is the proof - CGM is no longer to be considered "experimental and investigational."

Hey, insurers, it's time to change your policies.