Questioning CGM: A Lifesaver or an Overhype?

Raj is diabetic. He is dependent on medicines to keep his blood sugar levels in check. He uses a glucometer once or twice daily to monitor his blood sugar levels. This involves a bit of physical pain. But what makes matters worse is when the readings are haywire, he gets mentally disturbed.

Sudhir is also diabetic. But unlike Raj, he uses a Continuous Glucose Monitor (CGM) to track his sugar levels 24×7. He gets the readings via an app on his phone. He doesn’t need to prick himself, so the pain is obviously reduced. But when his phone beeps with constant alerts, it almost has him hyperventilating with anxiety. Besides, he’s still dependent on medicines to keep his blood sugar levels under control.

In contrast to the above two, Rahul has enrolled into the Wellfinity program for diabetes reversal. As per the program protocol, he needs to monitor his blood sugar levels only once a week or a fortnight. He is mentally in a better space and is working peacefully towards reversing the disease.

Now, the question is – which of the above three is more likely to find a sustainable and permanent solution to diabetes? The answer most obviously is Rahul, although it might not be in line with the conventional treatment of diabetes that lays far too much emphasis on blood glucose monitoring. (Do read our earlier blog to gain more insights on whether it is even required).

If you are diabetic, you would perhaps know that the most common tools used to track blood glucose are the normal Glucometers and CGMs or Continuous Glucose Monitoring tools. The basic difference between these tools lies in ‘how’ and ‘when’ they are used.

Glucometer measures Capillary Blood Glucose or CBG, or the glucose present in your tiny blood vessels called Capillaries. It requires you to prick your finger and extract a drop of blood and gives a one time reading with every prick. On the other hand, CGM measures interstitial glucose levels through a blood sugar monitor on the arm or belly. It reads your blood glucose continuously.

While the CGM has a unique role for research purposes and specific clinical scenarios, it comes with its pros and cons.

To begin with, the elementary problem with continuous glucose monitoring is that it focuses too much on the wrong parameter of diabetes – keeping blood sugar levels under control. Uncontrolled blood sugar is only a symptom of diabetes.

The focus of an efficient diabetes treatment protocol should rather be on the root cause and gross measurements such as losing 5-10 Kg weight, reducing the time taken for your daily 1 km walk, or your fasting insulin levels.  At Wellfinity, using a holistic, integrative and a functional medicine approach, we look to cure the disease from the root, rather than being dependent on insulin and medication for life.

In this blog, we discuss how CGM works, the pros and cons of CGMs, the controversy around it, its role in blood sugar monitoring, and its importance in athletics.

To CGM, or Not to CGM?

The biggest argument in favour of CGMs is that it is a real-time monitor – that is, it is an implantable glucose monitor that tracks your blood glucose throughout the day. Therefore, it gives you a comprehensive idea how different foods affect your blood glucose level without having to prick your fingers multiple times, which you would need to do while using a normal Glucometer.

When the CGM shows a spike, the patient can adjust his food accordingly in order to reduce sugar levels. CGM data could also provide clues to the physician to select the right protocol or adjust the patient’s medication/insulin, especially in the case of Type 1 diabetics who are dependent on external insulin.

However, it must also be said here that tracking a patient’s bodily reaction to something as diverse as foods on an Indian plate can be a very tedious and frustrating process. Moreover, sometimes the food may not be the cause of the spike at all.

We witnessed this in the case of Anushka who came to us with Type 2 Diabetes. Her previous doctor had put her on CGM and she had to eat the same meal combo for 10 days straight, eliminating one ingredient each day to figure out what was causing the spike in her blood sugar, after breakfast.

10 days later, her doctor came to the conclusion that the spike had nothing to do with the food. It was happening whenever she slept about 2 hours late on the previous night.

Now that we’ve answered the basic questions like how does a continuous glucose monitor work and do continuous glucose monitors hurt, let’s talk about its cons.

The flipside of CGM is that it measures interstitial glucose which lags behind blood glucose by 30 minutes. Moreover, it may be of great benefit in refractory cases where glucose control is resistant, but it is more costly than a normal Glucometer and certainly not needed for each and every diabetic.

You would know that stress is one of the leading causes of insulin resistance. The biggest problem with CGMs is that constantly checking the monitor could cause more stress, anxiety and mental fatigue in patients who are already suffering from these, thus completing a vicious cycle.

The biggest argument against the use of CGM is that is lays too much emphasis on blood sugar levels. It is noteworthy here that high blood sugar is merely a symptom of diabetes. One of the root cause of the disease is insulin resistance that may be caused by lipotoxicity of the liver, muscle or pancreas. This basic understanding of science is needed by the treating physician, rather than the focus on numbers.

Understanding Diabetes and the Importance of Monitoring Blood Glucose Levels

It is important to keep your postprandial blood glucose level below 150 mg%. The renal threshold for glucose is 180 mg%. When the blood sugar rises beyond 180mg%, it becomes dangerous for the body as it causes glycation of proteins and fats inside body, leading to glucotoxicity. If this glucotoxicity continues for a prolonged period, it can damage certain tissues such as the retina, nephrons and neurons.

So the natural mechanism of our body tries to pass off this excess blood glucose through urine. Hence, it is imperative to keep the glucose levels at least below 160-180 mg% if not below 150 mg%, which is considered ideal.

CGM gives an approximate idea about how well the blood glucose is controlled inside your body. Time in Range or TIR refers to the time percent during a 24-hour period when your blood glucose level stays between 70 and 180 mg%. Ideally, this TIR should be more than 70 % of the total time. TIR of 70% corresponds to A1c value of 7%, while TIR of 50% corresponds to the A1c value of 8.

Similarly, Time above Range (TAR) is the time percent when the blood glucose level is above 180 mg% and Time below range (TBR) is the time percent when the blood glucose level is below 70 mg%. When a patient hits TAR, it signifies severe diabetic concerns. And if a patient reaches TBR, it is an insulin shock warning.

The CGM Overhype

There is no doubt that the CGM is revolutionary if you consider its real-time monitoring perspective and that it doesn’t need you to prick your finger repeatedly. But the question is – should it be widely used in Type 2 diabetic population?

Continuous Glucose Monitoring is particularly relevant in the research studies and in selected cases of diabetic patients where the physician needs more information for optimal glucose control. CGM for Type 2 Diabetes is not a necessity as it is not mandatory to see how the body reacts to different kinds of macronutrients.

It has been the sales pitch of wellness programs across the country to advocate the use of CGMs for diabetes. The Wellfinity program focuses on diabetes reversal for life with lifestyle and dietary changes. It does not need CGMs or any other monitoring device, constantly.  If CGM is used regularly, it can be expensive. This unnecessary healthcare cost can be negated by a basic scientific understanding. Studies have already established how the body physiology reacts to different macronutrients. Equipped with this knowledge, physicians can eliminate the need for CGMs in most patients.

There is also a lack of standardisation in CGM devices that leads to inaccuracy in assessing and reporting, which causes confusion among clinicians and patients. There are different types of CGM devices in the market that have their own systems of functioning. The major differences can be seen in:

• How the device scans: CGMs have tiny built-in needle that test interstitial fluid glucose. The blood sugar sensor can be worn on the upper arm (skin patches), abdomen (chip), or upper buttocks.
• Frequency of glucose readings: These CGMs take automatic readings every 5-10 minutes or when prompted by user action. For instance, a user can wave the handheld reader over the blood sugar sensor to get a glucose reading.
• CGM sensors wear time: This differs from 10 to 20 days for different makes of CGM.

Such differences in readings can be very frustrating for patients. They are likely to lose confidence in the device when they see the value is much different from a normal finger-prick glucometer. Postprandial readings are more prone to inaccuracies and can be difficult for an already burdened patient to understand.

CGM in Athletics

CGM sensors have the capacity to capture the duration, magnitude and frequency of interstitial glucose fluctuations every 1 to 15 minutes. Theoretically, this can be used to monitor fuelling adequacy among athletes during their competitive events and training sessions. Manufacturers of athlete-specific devices market these as ‘fuelling gauges’ that enable athletes to push their limits further.

However, glucose homeostasis is a complex phenomenon. Extensive research is required to ascertain whether systemic glucose availability – which is estimated by CGM-derived interstitial glucose – has any meaning in relation to the intended purposes in sports.

Psychological consequences of CGM Overuse

Stress is one of the major reasons for diabetes. Routine use of CGMs further adds to the problem as it makes diabetics apprehensive about the occurrence of glucose spikes and causes constant emotional distress.

This distress keeps them in the sympathetic dominant mode (fight or flight). It does not allow rest and digestion which in turn becomes the cause of glucose spikes, thus completing a vicious circle.

Diabetics are already battling a disease they have no answers for or are not explained for by their healthcare practitioner. It makes them physically and mentally lethargic and they are not emotionally grounded.

Under such circumstances, it would be most advisable to avoid CGMs. However, CGMs could be employed in highly selective cases but the decision should be made by the treating physician rather than consumer demand.

CGMs are a good technological advancement in the diabetes care. The benefits of Continuous Glucose Monitoring are more prominent when it is used selectively in appropriate cases can be effective.

However, the use of Continuous Glucose Monitoring can have a negative impact on the treatment of average diabetes patients. Apart from the lack of standardisation and inaccuracies, continuous glucose monitoring can cause distress to the patient. Hence, it is not advisable to use CGM without prescription.

Moreover, CGM lays too much emphasis on blood glucose levels rather than the underlying root cause(s), such as insulin resistance amongst others. At Wellfinity, we look to eliminate the root cause(s) and reverse diabetes, rather than have it for a lifetime and keep monitoring the blood glucose levels with yet another fancy device.