The efficacy of continuous glucose monitoring systems in the management of blood glucose levels in Type 1 Diabetes mellitus

[Truncated abstract] Continuous glucose monitoring systems (CGMS) have the advantage over conventional self-monitoring of blood glucose (SMBG) of providing comprehensive blood glucose profiles without the need for numerous invasive finger-stick tests. Furthermore, current CGMS that provide glucose readings in real-time and are equipped with alarms for impending hypo- and hyperglycaemia have the potential to significantly improve the management of blood glucose levels. However, before CGMS can be successfully implemented into daily practice, the devices must have acceptable accuracy, and the limitations of current CGMS arising from physiological and technical factors must be properly identified and overcome. The purpose of this thesis was to investigate potential limitations of currently available CGMS with needle-type sensors (CGMS and Guardian RT; Medtronic, Minimed, Northridge, CA, USA), and to investigate their capacity for reducing the incidence and duration of hypoglycaemia, as well as increasing levels of physical activity by reducing fear of hypoglycaemia in individuals with type 1 diabetes in a real-life setting. Given the evidence that CGMS may overestimate blood glucose levels in response to metabolic acidosis, the first objective of this thesis was to validate the CGMS over a physiological pH range. Once this was established, the next objective was to evaluate whether CGMS with a real-time glucose display and a low glucose alarm used in a free-living context has the capability to increase the level of physical activity in individuals with type 1 diabetes mellitus (T1DM) by reducing their fear of hypoglycaemia. The third objective was to investigate the efficacy of CGMS with an appropriately set low glucose alarm and specific instruction for users for reducing the incidence and duration of hypoglycaemia in individuals T1DM.