As a diabetes doctor, I try to support my patients by providing medical and practical advice to help improve their diabetes control.
Among the topics we discuss regularly is what’s in their diabetes toolkit. The introduction of continuous glucose monitoring (CGM) marked significant progress in self-management by improving easy access to glucose data that may help inform treatment decisions and reduce the daily grind of diabetes. I use a continuous glucose monitor (CGM) and always have a blood glucose meter nearby. It is an essential part of my diabetes tool kit, and I recommend that my patients do the same. Here’s why:
BGM and CGM work differently. Blood glucose monitors – also called glucometers- measure sugar in the blood. In contrast, CGMs measure sugar in the interstitial fluid (ISF) in the subcutaneous tissue (fluid under the skin). The readouts from a CGM can differ from those on BGM because changes in glucose in the interstitial fluid can “lag” behind those in the blood, significantly when values are increasing or decreasing rapidly.
Checking with the glucometer may provide a better assessment of recovery from hypoglycemia. Given the lag between blood and ISF glucose levels, it may take extra time for higher values to be shown with CGM following treatment for hypoglycemia, often leading to additional intake of carbs and rebound hyperglycemia. In these circumstances, I check – and instruct my patients to do the same — with a glucometer 15 minutes after treating hypoglycemia, as it may provide a more accurate reading and help prevent overtreatment of hypoglycemia.
When the CGM device comes off, CGM sensors can detach at inopportune times. For example, patients tell me their CGM adhesive may not stick in warmer weather months if they’re sweating during a walk or while playing a sport, say a heated pickleball match. My sensor popped off when my arm brushed against the car door while I was getting out in front of my favorite restaurant. It was reassuring that I had a glucometer in my pocket and had an alternative way to check my glucose before the meal.
Fallibility—technology and human: No technology is perfect, and it follows that CGM sensors may not be 100% accurate all the time. Sometimes, people with diabetes experience symptoms that do not match the CGM sensor readings. And who among us hasn’t left their smartphone or CGM reader at home, or it wasn’t powered up? There are any number of other life situations where people with diabetes benefit from having an alternate testing method available.
Supply issues: In the last few years, many of us have experienced a delay in receiving our diabetes supplies. In case of a gap between CGM orders or the sensor received isn’t working correctly, it’s comforting to know that a glucometer, batteries, and test strips can be found at most local pharmacies.
A tech vacation: Data confirm that people using health monitoring technology experience physical and mental health benefits.1 But feeling overwhelmed by technology and burned out is not unusual. Need a break. On those days, people with diabetes may want their bodies to be device-free. Today, glucometers are also connected with tracking apps like mySugr, enabling healthcare providers to see uninterrupted relevant data.
Glucose monitoring is one of the most important parts of diabetes self-management. Whether used alone or alongside CGMs, having a glucometer in the toolkit provides critical information, peace of mind, confidence, and safety.
Brian Ulmer, MD, is a diabetologist in Indianapolis and a Roche Diabetes Care Medical Value Partner.
Sources
- Cleveland Clinic, https://newsroom.clevelandclinic.org/2024/02/01/cleveland-clinic-survey-most-americans-using-health-monitoring-technology-are-experiencing-significant-physical-and-mental-benefits-2
- Tanenbaum ML, Commissariat PV. Experience with burdens of diabetes device use that affect uptake and optimal use in people with type 1 diabetes. Endocr Connect. 2023 Sep 8;12(10):e230193. doi: 10.1530/EC-23-0193. PMID: 37522857; PMCID: PMC10503226.
- Cleveland Clinic, https://my.clevelandclinic.org/health/treatments/11444-glucose-continuous-glucose-monitoring