Technological Advancements in Glucose Monitoring and Insulin Delivery

Table of content

1. What is glucose monitoring?

Glucose monitoring is a way of testing the concentration of glucose in the blood. Glucose monitoring is important for diabetes management.

2. Steps involved in monitoring blood glucose

• To wash the hands and insert a test strip into the meter.
• To use a lancing device on the side of the finger strip (of the patient) to get a drop of blood.
• To touch and hold the edge of the test strip to the drop of blood and wait for the result.
• The blood glucose level will appear on the meter’s display.

3. Landscape of glucose monitoring technologies

The current technology for monitoring glucose levels has been well established since the 1980s. The practice is helpful l to patients with diabetes from both clinical and economic viewpoints.

The landscape of glucose monitoring technologies is expanding and rapidly changing. A few technological devices leading to improvements in glucose monitoring are discussed.

3.1) CGM (Continuous Glucose Monitoring)

3.1.1) What is CGM

CGM (Continuous Glucose Monitoring) automatically tracks blood glucose levels throughout the day and night. One can see his blood glucose level at a glance at any time. Further, one can also examine how blood glucose level varies over a few hours (or a few days) to assess and evaluate the trend.

Observing glucose levels in real-time can make one more informed and as such help decides how to balance food/ physical activity/ medicine throughout the day.

3.1.2) How CGM works

A  CGM works through a tiny sensor inserted under the skin (usually on the belly or arm).

The sensor measures one’s interstitial glucose level (it is the glucose level found in the fluids between the cells,  usually in the interstitial space.  As such, glucose measured in interstitial fluids may differ from blood glucose). The sensor tests glucose levels every few minutes. A transmitter wirelessly sends the information to a monitor. Some CGM sends information directly to smartphones.

3.1.3) Special features of CGM

CGM always keeps on recording glucose levels  (whether one is sleeping/ showering/ working/ taking exercise). CGM has many special features that are listed below.

• An alarm can sound when the blood glucose level of the patient goes too low or too high.
• One can also keep records of daily meals/ physical activity/ medicine in the CGM (In addition to the continuous recording of blood glucose levels)
• It is also possible to download glucose data on a computer or smartphone device so as to easily get information on blood glucose trends.
• Some models can send information in the right way to the smartphone of other people (parents/ near relatives/ health care providers). For instance, if the child’s glucose level drops to a dangerously low level overnight, the CGM could be set to wake the concerned person living in the next room.
• The currently approved CGM model is ‘Dexcom GM Mobile’. The model has the advantage of making changes in the diabetes care plan based on the CGM results alone.

3.1.4) How to handle CGM

• One needs to check blood glucose twice a day on a standard glucose meter.
• It is essential the to replace CGM sensor every 3 -7 days depending on the model.
• For safety purposes, it is important to take immediate action when a CGM alarm sounds signaling too high or too low blood glucose. The treatment plan needs to be well equipped to bring glucose levels within the targeted range.

3.1.5) Who can use CGM 

• Most people who use CGM have type-1 diabetes.
• CGMs are approved for use (in the case of the adults or the children) only after a doctor’s advice.
• The doctor recommends CGM for the patient only on intensive insulin therapy (it is also called high blood sugar control. It minimizes morbidity and mortality in patients kept under surgical intensive care unit)
• Patients who have hypoglycemia unawareness should use it.
• The doctor will best recommend whether to use CGM all the time or only for a few days (till the adjustment is made).
• Benefits of CGM: As compared to a blood glucose meter, using a CGM system is more helpful on the following grounds.
• CGM can better manage glucose levels every day
• It needs fewer finger sticks.
• A graphic image on the CGM screen shows whether the glucose level is rising or falling. It helps the patient (or the healthcare provider) to quickly choose the best way to reach the targeted glucose level.
• Over time, regular management of glucose levels greatly helps people with diabetes to stay healthy and prevent complications of the disease.

3.1.7) Limitations of CGM 

• One needs a finger stick for a glucose test to daily check the accuracy of CGM against a standard blood glucose meter (although, the researchers are working hard to make CGM more accurate and easier to use).
• With varieties of CGM models, one can’t rely on the CGM alone to make treatment decisions. (For instance, before changing the insulin dose, one must first confirm the CGM reading by doing a finger stick glucose test)
• A CGM system is more expensive as compared to a standard glucose meter

3.2) CLC (Closed Loop Control)

It is also known as .artificial pancreas. The technology links CGM with automatically controlled insulin delivery (it refers to different ways to inject insulin into the body. Different methods of insulin delivery include Syringes/ pens/ pumps /jet injectors. The jet injector is a needle-free device that drives liquid medication to intramuscular and subcutaneous tissues).

CGM is one part of the artificial pancreas system. 

The NIDDK (National Institute of Diabetes and Digestive and Kidney diseases) has played an important role in developing artificial pancreas technology. An artificial pancreas replaces manual blood glucose testing and the use of insulin shots. The artificial pancreas monitors blood glucose levels round the clock and provides insulin and a second hormone glucagon automatically (Glucagon is given by a shot and is used to treat severe low blood sugar called hypoglycemia by raising blood glucose levels). The system can also be monitored remotely.

In 2016, the US FDA (Food and Drug Administration)  approved a type of artificial pancreas system called the Hybrid Closed Loop System. The system tests the glucose level every 5 minutes throughout the day and night through a CGM and automatically provides the right amount of basal insulin (basal insulin helps regulate blood sugar levels in people diagnosed with diabetes. It keeps the glucose level steady) through a separate insulin pump.

Conclusively, the Hybrid Closed Loop System may keep the patient free from regular botherations (such as to keep the blood glucose level stable or to help the patient sleep throughout the night without the need to wake the patient in order to test glucose or take medicine). Still, it is wise to talk to the doctor as to whether the system is appropriate for the patient.

3.3) MTDS (Mobile Technology and Decision Support)

Recently, increasing connectivity between glucose monitoring technologies and mobile devices has facilitated ongoing improvements in self-care as well as communication of data.

It is evident that the isolated use  of glucose monitoring technologies without a plan for using data provides minimal benefits (particularly among the patients with type-2 diabetes, or who are not using insulin)

In order that glucose monitoring provides the maximum benefits, patients and healthcare providers must be able to easily obtain and communicate the data, and further, data must be organized in such a way that patterns can be identified and the patient can get the feedback at the time of care.

The widespread use of mobile devices provides opportunities for data collection/ analysis/ communication of the results to healthcare providers.

Conclusively, hurdles to wider implementation of mobile technology include lack of usability, lack of safety, and lack of cost-effectiveness.

3.4) AMGC (Alternative Markers for Glucose Control)

Some laboratory tests are there which can measure average blood glucose levels over a period of time. They are called ‘ Alternative Markers for Glucose Control‘. These are special markers in the body (that reflect blood glucose levels anywhere from a few weeks to a few months) giving insights into short and long-term blood glucose control. Hemoglobin A1C is one of the best markers to indirectly monitor blood glucose levels. A1C tracks the level of blood glucose over a period of 3 months (A1C is a common blood test used to diagnose type-1 and type-2 diabetes. It monitors how well the patient is managing blood glucose level).  

4. Concluding remarks

Many new technologies are emerging and increasingly being developed and applied to fight diabetes and its complications. New technologies are expected to improve the quality of life of people with diabetes by measuring glucose and other biomarkers (it is also known as a biological marker. It is a measurable indicator of some biological state or condition. Biomarker is commonly used in basic and clinical research) of glycemic control and linking glucose level with insulin delivery. In this connection, the NIDDK (National Institute of Diabetes and Digestive and Kidney Diseases) continues to explore and examine several important studies on different types of artificial pancreas devices (in the wake of technological improvements) in order to better help patients in the management of type-1 diabetes. This is also expected to help patients with type-2 and gestational diabetes.