The Frist Clinic's John Anderson, MD, on Making CGM Metrics Work With Type 2 Diabetes Patients

John Anderson, MD, of the Frist Clinic in Nashville, TN, is a primary care clinician specializing in diabetes care. In an interview with Patient Care© at the FMX annual meeting in October, he explained how standard glucose monitoring metrics, such as time in range and glucose variability, are transforming diabetes management.

Studies show that CGM use in adults with type 2 diabetes is associated with modest but meaningful improvements in HbA1c, increased time in range, and reduced time above or below range. For example, a recent systematic review and meta‐analysis found CGM use led to an average HbA₁c reduction of approximately –0.31% and a +6.36% increase in time in range compared with self‑monitoring of blood glucose.1 In a randomised trial of adults with poorly controlled type 2 diabetes on basal insulin, CGM resulted in a greater HbA₁c reduction over 8 months (–1.1% vs –0.6%) compared with conventional meter monitoring.2

Dr Anderson’s approach—starting with safety, then optimising time in range and reducing variability—is well aligned with current evidence supporting CGM use in type 2 diabetes.3

The following transcript has been lightly edited for style and flow.

Patient Care: What are the key metrics, such as time in range and glucose variability, that clinicians should focus on? How do these translate into treatment decisions?

John Anderson, MD: When you’re looking at the Ambulatory Glucose Profile (AGP) and all those metrics, the first thing to consider is safety. Ask: Is this patient going low at night without realizing it? Are they having episodes of hypoglycemia? If so, address that first. Even if the patient’s [HbA1c] isn’t where you want it to be, fix the hypoglycemia before moving on to other therapies.

Once that’s under control, then you can focus on optimizing other aspects of management. We now emphasize time in range—that’s glucose levels between 70 and 180 mg/dL, reflecting both fasting and postprandial (after-meal) control. Ideally, we want at least 70% of glucose readings within that range.

For hypoglycemia, aim for less than 4% of readings below 70 mg/dL and less than 1% below 54 mg/dL. For certain vulnerable patients, such as older adults or those with hypoglycemia unawareness, the goal for readings below 54 mg/dL should really be zero.

Next, look at the peaks. Are glucose levels going high? I often sit down with a patient whose fasting glucose looks great and midday readings are fine—but after dinner, they’re soaring to 250 mg/dL. That’s when we talk about what’s happening at dinner: is it a large carbohydrate load? Could reducing carbs help? Would walking after the meal make a difference? Do we need to adjust therapy to target postprandial elevations?

You walk through the data with the patient right there in the exam room. Review their medications, talk through patterns, and make decisions together to address specific issues.

PC: In a short primary care follow-up visit, how do you fit all of that in?

Anderson: It’s actually much easier now with AGP and continuous glucose monitoring data than it used to be with finger-stick logs. The sensor data make visits more efficient.

In my practice, the patient shares their data through the app, and I can pull it up right on my computer. I can review the past 7, 14, 30, or 90 days and immediately see where the highs and lows are occurring. You can identify patterns within one to two minutes—it’s that intuitive.

Once patients achieve good results—stable time in range, low variability, and a strong A1C—you can move on to all the other aspects of primary care that need attention beyond diabetes management.

Why Continuous Glucose Monitoring Matters

While CGM has long been standard in type 1 diabetes, evidence increasingly supports its use in type 2 diabetes as well. CGM provides near real-time glucose trends—both highs and lows—allowing clinicians and patients to move beyond episodic finger-stick readings or A1C alone.

Benefits include:

• Improved safety: Detects nocturnal or asymptomatic hypoglycemia that might otherwise go unnoticed.
• Better insights: Highlights post-meal glucose spikes and variability, guiding dietary, activity, and pharmacotherapy decisions.
• Enhanced engagement: Seeing glucose trends helps patients understand how meals, activity, and medications affect their glucose levels.
• Greater efficiency: Reviewing CGM data (via AGP) with patients in real time takes only a few minutes and supports collaborative care.

References

1. Here is the revised article text with inline references, followed by the reference list formatted in AMA style:

Making Sense of Glucose Metrics in Type 2 Diabetes

John Anderson, MD, of the Frist Clinic in Nashville, TN, is a primary‐care clinician specialising in diabetes care. In this Q&A, he explains how modern glucose monitoring metrics—such as time in range and glucose variability—are transforming diabetes management. Dr Anderson emphasises starting with safety, preventing low blood glucose events, and using continuous glucose monitoring (CGM) data to guide treatment decisions alongside the patient.

Q: What are the key metrics—such as time in range and glucose variability—that clinicians should focus on? How do these translate into treatment decisions?

Dr Anderson: When you’re looking at the Ambulatory Glucose Profile (AGP) and all those metrics, the first thing to consider is safety. Ask: Is this patient going low at night without realising it? Are they having episodes of hypoglycaemia? If so, address that first. Even if the patient’s A₁C (HbA₁c) isn’t where you want it to be, fix the hypoglycaemia before moving on to other therapies.

Once that’s under control, you can focus on optimising other aspects of management. We now emphasise time in range—that’s glucose levels between 70 and 180 mg/dL, reflecting both fasting and post‑prandial (after‑meal) control. Ideally, we want at least 70 % of glucose readings within that range.

For hypoglycaemia, aim for fewer than 4% of readings below 70 mg/dL and fewer than 1% below 54 mg/dL. For certain vulnerable patients—such as older adults or those with hypoglycaemia unawareness—the goal for readings below 54 mg/dL should really be zero.

Next, look at the peaks. Are glucose levels going high? I often sit down with a patient whose fasting glucose looks great and mid‑day readings are fine—but after dinner, they’re soaring to 250 mg/dL. That’s when we ask: what’s happening at dinner? Is it a large carbohydrate load? Could reducing carbs help? Would walking after the meal make a difference? Do we need to adjust therapy to target post‑prandial elevations?

You walk through the data with the patient right there in the exam room. Review their medications, talk through patterns, and decide together what to change for the specific issue.

Q: In a short primary‑care follow‑up visit, how do you fit all of that in?

Dr Anderson: It’s actually much easier now with AGP and continuous glucose‑monitoring data than it used to be with finger‑stick logs. The sensor data make the visit more efficient.

In my practice, the patient shares their data through the app, and I pull it up right on my computer. I can review the past 7, 14, 30 or 90 days and immediately see where the highs and lows are occurring. You can identify patterns in one to two minutes—it’s that intuitive.

Once patients achieve good results—stable time in range, low variability, and a strong A₁c—you can move on to all the other aspects of primary care that require attention beyond diabetes management.

Why Continuous Glucose Monitoring Matters

While CGM has long been standard in type 1 diabetes, evidence increasingly supports its use in type 2 diabetes as well. CGM provides near‑real‑time glucose trends—both highs and lows—allowing clinicians and patients to move beyond episodic finger‑stick readings or A₁c alone.

Benefits include:

• Improved safety: Detects nocturnal or asymptomatic hypoglycaemia that might otherwise go unnoticed.
• Better insights: Highlights post‑meal glucose spikes and variability, guiding dietary, activity and pharmacotherapy decisions.
• Enhanced engagement: Seeing glucose trends helps patients understand how meals, activity, and medications affect their glucose levels.
• Greater efficiency: Reviewing CGM data (via AGP) with patients in real time takes only a few minutes and supports collaborative care.

Studies show that CGM use in adults with type 2 diabetes is associated with modest but meaningful improvements in HbA₁c and increased time in range. For example, a recent systematic review and meta‐analysis found CGM use led to an average HbA₁c reduction of approximately –0.31% and a +6.36% increase in time in range compared with self‑monitoring of blood glucose.¹ In a randomised trial of adults with poorly controlled type 2 diabetes on basal insulin, CGM resulted in a greater HbA₁c reduction over 8 months (–1.1% vs –0.6%) compared with conventional meter monitoring.²

Dr Anderson’s approach—starting with safety, then optimising time in range and reducing variability—is well aligned with current evidence supporting CGM use in type 2 diabetes.³

References

1. Jancev M, Vissers TACM, Visseren FLJ, et al. Continuous glucose monitoring in adults with type 2 diabetes: a systematic review and meta‐analysis. Diabetologia. 2024;67(5):798‑810. doi:10.1007/s00125‑024‑06107‑6
2. Martens T, Beck RW, Bailey R, et al. Effect of continuous glucose monitoring on glycemic control in patients with type 2 diabetes treated with basal insulin: a randomized clinical trial. JAMA. 2021;325(22):2262‑2272. doi:10.1001/jama.2021.7444
3. Mir F, Liu H, Han J, et al. Effectiveness of continuous glucose monitoring on metrics of glycemic control in type 2 diabetes: a systematic review and meta‑analysis of randomized controlled trials. J Clin Endocrinol Metab. 2024;109(4):1119‑1130. doi:10.1210/clinem/dgad652