Diabetes mellitus is a metabolic disorder characterised by hyperglycaemia (high blood sugar) resulting from defects in the production of or in the body’s response to insulin. The disease has two main forms: type 1 and type 2. Type 1 disease is characterised by diminished insulin production resulting from the loss of beta cells in the pancreatic islets of Langerhans, in most cases caused by immune-mediated cell destruction. Disease management entails administration of insulin in combination with careful blood glucose monitoring. Type 2 diabetes sufferers in contrast exhibit both reduced insulin production and resistance or reduced sensitivity to insulin. Type 2 diabetics are typically over 50 years old with additional health problems, especially cardiovascular disease (CVD). Management principally involves the adjustment of diet and exercise level and the use of oral anti-diabetic drugs (OADs) and insulin to control blood sugar.

Diabetes mellitus has reached epidemic proportions in western countries (Zimmet, P., Alberti, K.G., Shaw, J. (2001): Global and societal implications of the diabetes epidemic. Nature 414:782-787, 2001). Diabetes type 2 is one of the fasted growing chronic conditions in the developed world. In Britain, a total of about 3% (1.3 million) of the population have diagnosed diabetes. It is estimated that an additional 2% of the population have undiagnosed diabetes. Type 2 diabetes is very closely linked to the emerging epidemic of obesity and life style, which is now a major cause of preventable health problems. The associated morbidity and mortality of diabetes represents a major healthcare burden. (Image reprinted with permission from Medscape.com, 2010. Available at: http://cme.medscape.com/viewarticle/533668_1)

Diabetes can cause many complications if the disease itself and associated risk factors (e.g. blood pressure and hyperlipidemia) are not adequately controlled. These complications include CVD, chronic renal failure, eye disease leading to blindness and neuropathy. Thus, diabetes increases CVD risk 2-3 fold, which is the most common cause of renal failure and blindness, and increases the risk of amputation by 20-30%. There is abundant evidence that shows tight control of the blood glucose level to be vital for good diabetes management and insulin therapy. Good glucose control requires frequent measurement of blood glucose levels and complicated algorithms for assessing the insulin dose needed to adjust for short term variations in activity, diet and stress. On the other hand, good control of diabetes, as well as increased emphasis on blood pressure control and lifestyle factors, may improve the risk profile of most complications and attain future good health. Hence, self-management of diabetes is an area that offers exceptionally good prospects, both in clinical terms and in economical terms.

The overall health status of type 2 diabetics can be improved by adequate treatment of diabetes and of the associated risk factors. Self-management of diabetes in which the patient measures blood glucose several times a day and uses the resultant data to gauge the required insulin dosage is a promising modality. Blood glucose is typically measured in a drop of capillary blood using a disposable dry chemical strip and reader device, an uncomfortable and slow process. Tight Glucose control (TGC) requires almost continuous measurements and different sensors for continuous blood glucose measurement have been under development for the last two decades. Minimally invasive sensors able to measure glucose in interstitial fluid, and thus more suitable for self-monitoring, have also been developed. To date, however, none of these has delivered a level of performance sufficient for use in routine glucose monitoring. Robust, clinically acceptable devices are however widely expected to become available in the near term.

The REACTION platform will be developed with a view to integrating the most promising transcutaneous and minimally invasive continuous glucose sensor into an ePatch technology platform.