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The impact of continuous glucose monitoring for people with type 1 diabetes: A focus on everyday life

Book - Dissertation

In type 1 diabetes (T1D) the individual's immune system attacks the insulin producing beta cells of the pancreas and destroys them. Therefore, people with T1D need exogenous insulin to survive, however, achieving optimal glycaemic control while avoiding hypoglycaemia remains a challenge despite rapid advancements in insulin administration technology and better insulin preparations. To inject the right dose of insulin, it is essential that the amount of glucose in the blood is known. Checking blood glucose levels several times a day and administering the correct amount of insulin based by taking into account several other factors (e.g., carbohydrate load to be consumed, planned physical activity) is a daily reality for people with T1D, but also a 'task' with a major impact on quality of life (QOL). For many decades, the frequent execution of capillary finger-stick tests was the only way to have a notion of blood glucose values. Unfortunately, not many people perform this test frequent enough, while successful intensive insulin treatment requires close self-monitoring of blood glucose. By using capillary finger-stick tests, many glucose fluctuations were missed during the day, and the nights remained unknown. The introduction of continuous glucose monitoring (CGM) has overcome some of the limitations of capillary finger-stick tests. There are generally two types of CGM systems available depending on the level of user-interaction needed to receive sensor glucose information: real-time CGM (rtCGM) continuously shows updated glucose information and provides real-time alerts and alarms for hypo- and hyperglycaemia; intermittently scanned CGM (isCGM) requires the user to deliberately scan the sensor to obtain the same information as rtCGM, and therefore does not have alarms for hypo- and hyperglycaemia. Randomised controlled trials (RCTs) with CGM showed favourable results on hypoglycaemia risk, HbA1c (only for rtCGM), but often neglected the patient perspective of diabetes self-management and omitted the incorporation of patient-reported outcome measures. Additionally, RCT circumstances do not reflect the real-life use of the devices, because the study population is often highly motivated to do well, and therefore, these results are not always generalisable to the broad population of people living with T1D and thereby hamper with reimbursement policies. Real-world evidence (RWE) can provide filling for the knowledge gap and combine clinical with patient reported outcomes. Uniquely, Belgium has launched reimbursement programmes for both rtCGM and isCGM, providing an excellent soil for large real-life usage studies. Therefore, in the first two parts of this project, we evaluated the use of rtCGM and isCGM and their effect on glycaemic control, QOL, and acute diabetes-related complications in real-world clinical practice. First, rtCGM was introduced in a population where people were selected, not on the basis of stringent inclusion and exclusion criteria imposed by a healthcare organiser, but rather based on the clinical expertise of experienced diabetes teams. This approach proved successful as the diabetes teams selected highly motivated people who were able to attain a high benefit from rtCGM technology during at least two years with positive effects on patient-reported outcomes, especially people with impaired awareness of hypoglycaemia. Second, isCGM was introduced in an unselected population as part of the nationwide full reimbursement of isCGM for all people with T1D in Belgium without restrictions or specified inclusion criteria. Adults and children were very satisfied with the use of isCGM with additional benefits on acute diabetes-related complications and school absence for children. In well-controlled adults and youth, HbA1c rose after introduction of this new technology. It became clear that the use of this technology requires a certain level of user interaction and diabetes knowledge to prove beneficial. Therefore, a good understanding on the glucose sensor output is needed and regular re-education is warranted to avoid people making wrong treatment decisions based on CGM data. In the third part of this project, we searched for evidence-based alternative sensor insertion sites for people who use isCGM, but cannot harness its full potential due to issues with a too visible sensor attached to the back of the upper arm. In an interventional study, we identified the upper thigh as a good alternative, accuracy-wise, for the arm. The abdomen, the main insertion site for rtCGM devices, proved to be unreliable in this factory-calibrated sensor. As a general conclusion, with our studies, we have shown that the Belgian way of working, namely introducing technology within conventions with a focus on diabetes education, can have beneficial effects on health and patient-reported outcomes. This has made isCGM and rtCGM available to a wider group of people with T1D.
Publication year:2020
Accessibility:Open