The continuous glucose monitor is an extraordinary tool.
Studies have shown that continuous glucose monitoring (CGM) use by people with diabetes can have a multitude of health benefits. Patients on CGM technology often have lower A1c levels, fewer highs and lows, and spend more time in their target blood glucose range. Also, CGM use has been associated with a higher quality of life; users often report a diminished fear of low blood sugar levels, increased self-confidence in making diabetes treatment decisions, and feeling more independent. CGM users are also less likely to experience diabetes distress.
The CGM also gives doctors and researchers an unprecedented wealth of glucose data. It has also given rise to a new statistic, time in range, which assesses how often blood glucose is within a safe range. Looking at comprehensive and real-world data trends in different patient populations can help us understand what is working and what’s not, and over time, adjust recommendations accordingly, and perhaps with a more personalized approach.
Unfortunately, the latest data shows that most people with diabetes fail to reach recommended glucose targets.
The Latest Time in Range Data
A recent study led by expert Richard M. Bergenstal, MD aimed to evaluate just how many people with diabetes in the US are achieving the recommended time in range (TIR), by looking at CGM data from almost 500 people with type 1 and type 2 diabetes over four years (2016-2020). This was an observational study – researchers did not interfere with participants in any way, and simply collected the real-life data. They ended up with close to 5,000 ambulatory glucose profiles (AGPs), and assessed TIR and hypoglycemia trends.
The results, which were just presented at the American Diabetes Association (ADA) 81st virtual Scientific Sessions, offer a unique glimpse into common glucose trends.
Dr. Bergenstal’s team looked at how frequently people with CGMs were able to achieve the most widely accepted TIR targets.
The International Consensus in Time in Range (TIR) … defined the concept of the time spent in the target range between 70 and 180 mg/dL while reducing time in hypoglycemia, for patients using Continuous Glucose Monitoring (CGM).
The team also evaluated how many participants spent less than 1% of the time with severe hypoglycemia (under 55 mg/dL).
Vast Majority Are Not Meeting TIR Goals
On average, only 39% achieved the recommended TIR goal. Only about 32% were able to meet both the TIR goal and meet the goal for minimal time in severe hypoglycemia (less than 1% of glucose readings <55 mg/dL). Of note, there was no appreciable difference between the first AGP evaluated and the average over the four years, suggesting that these trends didn’t change much over time.
The differences between those with type 1 diabetes and type 2 diabetes, however, were staggering.
Only 35% of type 1s achieved the recommended TIR, with fewer than 30% also being able to avoid significant hypoglycemia. In contrast, 53% of type 2s were able to meet the TIR target, with exactly half achieving this without experiencing severe low blood sugar levels frequently.
It may not come as a surprise that the targets were achieved more frequently by those with type 2 diabetes. People with type 1 diabetes, who have little or no insulin production, tend to experience more significant blood sugar swings than those with type 2. Hitting management targets is often more complex in this population, especially given the fear of hypoglycemia, which for so many goes hand in hand with insulin use.
The authors conclude,
Less than half of the population achieved ≥70% TIR, ~30% with ≥70% TIR and <1% time in clinically-relevant hypoglycemia. This indicates an opportunity to improve attainment of TIR goals, and an ongoing need to support the use of CGM data to help optimize care.
What Can Be Done to Improve Outcomes?
This investigation provides a sobering glimpse into the reality of life with diabetes, even as technology becomes more widely used. How exactly do we use this information to begin to help people with diabetes reach their treatment goals and improve their health outcomes?
The answer to this question is complicated. We know that achieving better health outcomes, in the short and the long term, largely rests on optimizing blood glucose levels in people with diabetes. It is well-established that blood sugar levels are directly responsible for the mountain of diabetes-associated complications that patients are repeatedly warned about. It follows, that if it was easy, everyone would be getting an A1c of <7%, and possibly opting for even tighter goals.
Where are we failing in helping people achieve their diabetes management goals?
This is the ultimate question, and one that likely has many components, and varies for different individuals. Leading health organizations should be taking deep dives to figure out these answers so that we can actually begin to develop more effective solutions. Here are just some of my thoughts on the matter:
Some people posit that outdated dietary recommendations are largely to blame. They may have a point. Despite the existence of a slew of literature showing the benefits of lowering carbohydrate intake, there is still a lack of widespread understanding and patient counseling on this approach, especially in the clinic. The quantity and quality of carbohydrate intake is absolutely at the heart of diabetes management, and has a huge role to play in dictating success vs. disappointment.
Carb restriction is not necessarily the only eating pattern that confers glucose benefits, it’s just a prominent example. At the very least, all patients should be educated on a variety of dietary approaches in detail, and understand the pros and cons of their options, so that they can make the best choices for their overall health.
Moreover, there likely needs to be more comprehensive guidance on self-adjusting medications around lifestyle variables. Diabetes is not static. Blood sugar levels are dictated by a complex and extensive array of factors. From our current weight to our exercise patterns, to stress and travel, among many others variables, patients need to feel confident and empowered to self-adjust their management dynamically. Too many people with diabetes rely entirely on a diabetes specialist to change their treatment plan on a quarterly basis, at best. We need to empower people with diabetes to become their own “diabetes specialists”.
Armed with knowledge, the tools they need, along with the support of a well-informed provider, I hope we can begin to see a change in these trends.
Read more about A1c, American Diabetes Association (ADA), continuous glucose monitor (CGM), diabetes management, exercise, insulin, Intensive management, low blood sugar (hypoglycemia), time in range.