In Pursuit of an Ideal – A Perspective on Non-Invasive Continuous Glucose Monitoring
Diabetes is one of the most common non-communicable diseases globally, and is the fourth or fifth leading cause of death in many countries. Medical technology for the management of diabetes has advanced steadily since the discovery of insulin in the early 20th century. Today, individuals with diabetes benefit from home-use blood glucose meters, continuous insulin pumps and, most recently, continuous glucose monitoring (CGM). Numerous studies have shown that frequent use of real-time CGM can improve glycaemic control with reduced risk of hypoglycaemia. However, current CGM devices have not been wholeheartedly embraced, limiting their potential. A CGM device that is accurate, non-invasive, pain-free and non-intrusive to daily activities could drive increased adoption and use of CGM, potentially improving health and quality of life for many individuals living with diabetes.
Approximately 366 million individuals worldwide have type 1 or type 2 diabetes, and it is likely that global prevalence will rise to 552 million individuals by 2030.1 Currently, an estimated 4.6 million deaths are attributed to diabetes annually.1 Undisputedly, the best way to address this ‘diabetes epidemic’ is through a global commitment to prevention, early diagnosis, accurate monitoring and effective treatment.
Criticality of Tight Glycaemic Control
The comprehensive, 10-year Diabetes Control and Complications Trial (DCCT) in 1993, which established glycated haemoglobin (HbA1c) as a gold standard measure of long-term glycaemic control, clearly demonstrated that individuals with type 1 diabetes who kept blood glucose levels as close to normal as possible for as long as possible had less chance of developing disease-related complications.2–4 Since that time, other studies have confirmed the importance of tight glycaemic control with minimal glucose excursions in reducing disease-related complications not only in type 1 diabetes, but also in type 2 diabetes.5–9 Today, individuals with diabetes are encouraged to maintain blood glucose at normal or nearnormal levels. Furthermore, those who take insulin injections are encouraged to follow intensive treatment programmes with tight glycaemic control targets, which require frequent glucose monitoring.10
Barriers to Tight Glycaemic Control
Despite advances in technologies and therapeutics, intensive treatment of type 1 diabetes frequently fails to achieve target HbA1c as recommended by the DCCT more than 15 years ago.11 Many individuals – including those who measure blood glucose several times daily – still experience postprandial hyperglycaemia and asymptomatic nocturnal hypoglycaemia.12,13 These findings suggest that tight glycaemic control is difficult to achieve for many individuals with diabetes. There are a variety of reasons for this, including fear of hypoglycaemia, poor adherence to self-monitoring of blood glucose (SMBG) and lack of continuous data about glucose dynamics.
Hypoglycaemia can lead to neurologic, cognitive and cardiovascular dysfunctions, and if left untreated, death.13 Frequent hypoglycaemic episodes can cause ‘hypoglycaemia unawareness’, a condition that leaves an individual unable to recognise hypoglycaemia when it occurs. As the most feared complication of insulin therapy,14,15 hypoglycaemia is the main reason why individuals with diabetes who take insulin injections are hesitant to pursue intensive blood glucose control.11
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