Continuous Vs. Flash Monitoring of Blood Glucose in Diabetes Management
Author: Luca Vita
Diabetes mellitus, in all forms, continues to be a global burden with the prevalence ever-growing. In the last three decades, there has been over a 400% increase in the number of individuals diagnosed with the disease (1). Diabetes is clinically classified into two main categories based on the certain pathology of the disease, although there are other less common subtypes. Type 1 diabetes mellitus (T1DM) is described as an autoimmune disease (2), whilst type 2 diabetes is a developmental disease that is associated with obesity (3).
In both types of diabetes as a result of low/ineffective insulin, there can be a build-up of glucose in the blood known as hyperglycaemia. Persistent hyperglycaemia, as with diabetics can lead to a whole array of health issues if it is not managed. In the most severe cases, it can lead to a diabetic coma and death, however, more commonly diabetes leads to complications with the eyes, kidney, heart, nerves and circulation (4). Alternatively, patients could experience a hypo, in which their blood glucose is too low. This can lead to confusion and drowsiness, or eventually becoming unconscious and suffering a fit. Therefore, the effective management of blood glucose concentrations in diabetic individuals is vital.
Traditionally, blood glucose levels were managed via the finger prick method. In which an individual would prick their finger with a device called a lancet, to draw a drop of blood. The blood was then placed on a test strip to determine their blood glucose levels. However, more recently, technologies have moved to under skin testing with the use of flash or continuous testing.
Flash Glucose Monitoring
A flash glucose monitor is a small sensor that sits just under the skin of a patient. The sensor does not directly measure the blood but instead measures the amount of glucose that is present in the interstitial fluid that surrounds cells. The flash monitor also comprises a reader that you swipe/scan over the sensor allowing you to check the readings. The flash sensors generally last between ten to fourteen days before they need to be replaced (5).
The flash glucose monitor is a simple and easy to use device that gives individuals with diabetes more freedom and control over the management of their condition. It provides more data than the finger prick method as patients can look back at trends and better understand their own condition. Due to a slight time delay in the reading, the flash monitor reduces but does not completely eliminate the need for finger-prick tests. They still may be necessary when a more accurate reading is required. Additionally, another disadvantage to the flash monitor is due to its ‘scan-as-you-go’ nature there is no ability to set alarms for high or low blood sugar levels. This means the sensors are not particularly good at warning when an individual may be experiencing hyper or hypoglycaemia. Finally, due to the use of precious metals in the sensing device, the monitors come with a large price tag, with many patients stating they are not affordable (5).
Continuous Glucose Monitoring
A continuous glucose monitor works in a very similar way to that of the flash monitor. Like the flash, it is a small sensor that is worn underneath the skin that measures the amount of glucose that is present in the interstitial fluid. However, unlike the flash monitor, the continuous sensor contains a transmitter that sends continuous data to a display device, e.g., a smartphone. As the name suggests this allows for continuous glucose monitoring (6).
The biggest advantage of this method of monitoring is the ability to track blood glucose levels 24/7. This is ideal for an individual that suffers from more frequent or more severe hypos, or for parents with young children who suffer from the disease. Furthermore, alarms can be set for when blood sugar concentrations are too high or too low. These alarms can be set to detect when levels are starting to climb or fall, allowing a patient to take preventative action to stop hypo or hyperglycaemic episodes as opposed to reacting to them. However, like the flash monitor, the continuous monitors do not completely eliminate the need for finger-prick testing. Furthermore, due to the use of enzymes in the sensor they are required to be changed every seven days. Lastly, like the flash monitors, the continuous monitors are deemed an expensive solution to blood glucose management (6).
What are the next innovative steps?
Under the skin sensors come with a range of benefits that have given patients with diabetes more control over the management of their condition. They are considered to be a better alternative to finger-prick testing and have helped improve the lives of many. However, with their range of limitations, they are still below the standard that healthcare demands today.
Currently, continuous and flash glucose monitors rely on the use of precious metals as part of their sensing technology. Gii is our 3D printed carbon foam that can replace the need for such metals. It offers the same performance as the current electrodes, but without the expense and price variability of precious metals. Furthermore, Gii-Sens has a patented one-step production process and is compatible with high volume manufacturing processing, enabling low production costs. These key characteristics, combined with a fully cooperative development between yourself and integrated graphene can help you exploit the full potential of your products. Finally, Gii-Sens also boasts a fully customisable electrode design with a label-free assay format. Importantly, this removes the need for enzymes, a key limiting factor with current technologies.
For more information on integrating Gii-Sens into your continuous glucose monitor, contact us today.
References:
Diabetes Mellitus. WHO. [Online] 2020. [Cited: July 25th, 2021.] https://www.who.int/news-room/fact-sheets/detail/diabetes.
Definition, Classification and Diagnosis of Diabetes Mellitus. Kerner, W and Bruckel, J. s.l. : Exp Clin Endocrinol Diabetes, 2014, Vol. 122.
Adult obesity and type 2 diabetes. Gatineau, M. et al. London : London: Public Health England, 2014.
Hyperglycemia and Glycation in Diabetic Complications. Negre-Salvayre, A. et al. 12, s.l. : Antioxidants and Redox Signalling, 2009, Vol. 11.
Diabetes UK. continuous glucose monitoring (cgm). [Online] [Cited: July 25th, 2021.] https://www.diabetes.org.uk/guide-to-diabetes/managing-your-diabetes/testing/continuous-glucose-monitoring-cgm.
Diabetes UK. flash glucose monitoring. [Online] [Cited: July 25, 2021.] https://www.diabetes.org.uk/guide-to-diabetes/managing-your-diabetes/testing/flash-glucose-monitoring#flash-work.