Glucose Monitoring in Diabetes

Dr Roger Mazze explains why monitoring is indispensable for better managing glucose levels.

Ambulatory glucose profile explained

When self-monitoring was first introduced way back in the 1980s, I developed a way of capturing the glucose values and then representing them to find any underlying patterns. However, self-monitoring is done primarily during the day time. It is intermittent and many individuals forget to timely monitor or do so only when they are feeling sick. But the data from Self-monitoring of Blood Glucose (SMBG) does not give a full picture. Continuous Glucose Monitoring (CGM) introduced in 2001 made it possible to take continuous measurements and to find the underlying patterns.

Ambulatory Glucose Profile (AGP) aggregates about two weeks of glucose levels and helps the physician look for patterns that would show hypoglycaemia, excess glucose exposure, significant glucose variability and all the characteristics that help understand the blood sugar trends of a person with Diabetes.

At present, AGP seeks to find ways to use it to quickly detect the problems that a patient might face or better yet, anticipate problems. For instance, since we can now identify the risk of overnight hypoglycaemia, we know that if blood sugar levels are lowered during the day time, the overnight glucose values also have to be recorded. Intervention should involve reducing fluctuation blood glucose levels then improving glucose stability and then manage glucose exposure. This helps prevent hypoglycaemia. Understanding how and why glucose levels fluctuate can help to anticipate and avoid hypoglycaemia.

Ambulatory glucose profile is a graphics program that shows glucose patterns. The most important component of it is the ability to see the glucose patterns, to see where it is hypoglycaemic, where it is hyperglycaemic and to see the variability and the excess exposure. The patterns are also quantifiable and it does report out values. What is to be looked for is that AGP becomes a standard for reporting continuous glucose monitoring.

Benefits of AGP

A person with Type 1 Diabetes even with continuous monitoring looks at individual values. They do not see an underlying pattern. So for them to learn and to get feedback, the most important thing to see is when their glucose levels tend to rise. So once you have the pattern, it begins to get you to think about what things you need to do. It gives excellent feedback. The only way you are going to determine whether your glucose goes up or stabilises or in fact not move at all is by seeing repetition in the pattern. AGP is meant to show patterns. One of the fundamentals in medicine is pattern recognition.

A person with Type 2 Diabetes can use AGP for immediate feedback and to highlight a trend. Food, exercise, stress, sleep and activity all of these affect glucose levels just the way insulin does. Knowing what is happening with regards to sugar levels guides in making corrections in your lifestyle or report back to the doctor whether a therapy is working.

AGP is useful for people with prediabetes to see whether an intervention in lifestyle, adding exercise or losing weight would, in fact, change their profile.

AGP and Gestational Diabetes

AGP is recommended in Gestational Diabetes. Observing glucose levels is of paramount importance in gestational Diabetes as it can put the mother and the child at risk. Low levels are considered to be better, as high levels may lead to a poor outcome. Diabetes during pregnancy, either GDM or pre-GDM, requires underlying predictive patterns to be checked to initiate immediate intervention. So what is required is the tightest control possible. Continuous glucose monitoring helps analyse underlying patterns and not just single glucose value to determine how best to manage it.

CGM and children

CGM works wonders for children. For one thing, it helps parents to sleep through the night because if the child is hypoglycaemic, with alarm systems and other means they are awakened rather than staying up all night watching the child. CGM has been used in children, very safely, with no significant problems.

To conclude

Devices like CGM or flash glucose monitoring or SMBG will only make a difference when the physician is properly trained to use the information. Any device's true benefit only comes when the information it produces gets used by the clinician to make a productive clinical decision that helps the patient. Simply giving it to the patient and expecting better outcomes doesn't work. The patient has to be educated, the physician has to be educated and that applies for even the simplest devices such as SMBG to the most complex devices such as CGM and insulin pumps. Education is the basis for everyone – the physician, the patient, the nurse member of the team and the dietician member of the team. All have to be able to understand how to collect the data, look at it, analyse it and use it.