Adjusting Insulin With the Help of CGM: Focus on Four Patient Subgroups
Dr. Martens noted that about a quarter of people with T2D will require insulin treatment, despite increasing use of sodium-glucose cotransporter 2 (SGLT2) inhibitors and glucagon-like peptide 1 (GLP-1) receptor agonists. And even when insulin is used as a “salvage therapy” in T2D, about two thirds of those individuals still struggle to achieve an A1c below 7% with or without other glucose-lowering medications, he noted.
“So, we have this huge population with type 2 diabetes who have limited access to endocrinology, and advanced insulin delivery devices are not yet available for them. Can better use of CGM drive improvements in care?”
He pointed to MOBILE, a randomized clinical trial, which showed that CGM use resulted in significantly improved A1c at 8 months compared with fingerstick monitoring among adults with T2D taking long-acting insulin alone without premeal insulin. However, TIR was still just 59% (vs 43% with fingerstick testing), suggesting room for improvement.
“This could have been much, much better…Rapid interpretation isn’t really enough. We need to move from interpretation into action,” Dr. Martens said.
His team recently developed a program called “CGM Clinician Guided Management (CCGM)” aimed at primary care that encourages the following principles:
- Appropriate movement toward the safer “high value” noninsulin therapies, that is, GLP-1 agonists and SGLT2 inhibitors.
- Appropriate insulin titration.
- Appropriate cycle time in titration, that is, accelerating more rapidly when one dose isn’t working. “That’s the Achilles heel of primary care,” he noted.
- Quick identification of when the limits of basal insulin therapy have been reached.
- Team-based management for difficult situations and for individuals on multiple daily injections and mealtime insulin regimens. “This is a group that really struggles…in primary care settings,” he noted.
The following three steps are based on published T2D management guidelines:
- Step 1: If the patient has atherosclerotic cardiovascular disease, start with either an SGLT2 inhibitor or GLP-1 agonist. For those with congestive heart failure and/or chronic kidney disease, SGLT2 inhibitors are indicated.
- Step 2: Is the patient on sulfonylurea? Consider eliminating it before moving to CGM-based insulin titration.
- Step 3: Was there a change in therapy based on steps 1 or 2? If not, move to CGM-guided insulin titration. If yes, wait 2-4 weeks to see the impact of therapy change before moving on.
The program categorizes patients into one of four groups based on CGM data, with respective management approaches:
- Category 1: TIR > 70%, time below range (TBR) < 3%: Doing well, keep on going!
- Category 2: TIR > 70%, TBR ≥ 3%: Too much hypoglycemia, need to decrease therapy. Stop sulfonylureas, and if TBR > 10%, also decrease basal insulin dose.
- Category 3: TIR < 70%, TBR < 3%: Too much hyperglycemia — increase therapy.
- Category 4: TIR < 70%, TBR ≥ 3%: This is the toughest category. Fix or advance therapy. These patients should be either referred to a diabetes care and education specialist (formerly known as “diabetes educators”) to troubleshoot their regimens or have their therapy advanced to multiple daily injections. The hypoglycemia should be addressed first for safety, then the hyperglycemia.
“We hope that CCGM is going to be the translation of CGM data into action in primary care, where we struggle with action and inaction,” Dr. Martens said. It’s expected to be posted on the IDC website soon.
Ms. Ettestad’s employer received educational grant funds from Abbott Diabetes Care and Sanofi-Aventis Groupe. She also worked as a product trainer with Tandem Diabetes Care. She is employed by nonprofit International Diabetes Center – HealthPartners Institute and received no personal income or honoraria from these activities. Dr. Martens’ employer received funds on his behalf for research and speaking support from Dexcom, Abbott Diabetes Care, Medtronic, Insulet, Tandem, Sanofi, Lilly, and Novo Nordisk and for consulting from Sanofi and Lilly. He is employed by nonprofit HealthPartners Institute – International Diabetes Center and received no personal income or honoraria from these activities.
A version of this article first appeared on Medscape.com.