Answer FAQs About Continuous Glucose Monitoring

More patients will ask about continuous glucose monitoring (CGM).

When should you use CGM? The Am Diabetes Assn now recommends CGM across the board for patients using insulin...including basal only.

Overall, evidence suggests CGM can improve A1c and reduce hypoglycemia...especially with multiple insulin injections per day.

But data are more limited with non-insulin regimens.

Continue to individualize your glucose monitoring recommendations.

For example, offer CGM for a patient on multiple daily insulin injections or with frequent hypoglycemia...especially those likely to be motivated by seeing glucose levels in real time.

But don’t jump to CGM for most patients using only oral meds...or if the extra data aren’t likely to drive changes.

How do CGMs compare? Dexcom G7 will now compete with FreeStyle Libre 3. Both automatically send results to a compatible smartphone.

G7 can also send results to a smartwatch or a separate handheld receiver...Libre 3 will offer an optional receiver later this year.

Clarify other differences. Dexcom G7 sensors are good for up to 10 days...current FreeStyle Libre 3 sensors are good for 14 days.

Explain that both systems have good accuracy...based on how closely results match finger-stick glucose.

But patients STILL need to check a finger stick with a standard meter if prompted...or results don’t match how they feel.

G7 sensors cost about $350/month...Libre 3 sensors cost about $130.

Expect CGM to be covered by most payers...including for some patients with type 2 diabetes. But a prior auth may be needed...or it may be covered as durable medical equipment (DME).

What are tips for success with CGM? Educate on CGM metrics.

For example, identify the time in range (TIR)...the amount of time patients are in their sweet spot, such as 70 to 180 mg/dL. In this case, advise aiming for a TIR above 70%...if A1c goal is below 7%.

If CGM sensors don’t stay on despite carefully cleaning the site first, suggest a product to improve adhesion (Skin Tac, Tegaderm, etc).

Get our resource, Continuous Glucose Monitoring, for ways to manage skin irritation, meds that interfere with CGM, and billing guidance.

Key References

  • Diabetes Care. 2023 Jan 1;46(Suppl 1):S111-S127
  • Diabetes Care. 2023 Jan 1;46(Suppl 1):S97-S110
  • Medication pricing by Elsevier, accessed Apr 2023
Prescriber's Letter. May 2023, No. 390502

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