Hyperglycaemia in hospitalized patients is becoming a common clinical problem due to the increasing prevalence of diabetes mellitus. Hyperglycaemia in this cohort can also occur in patients with previously undiagnosed diabetes, or during acute illness in those with previously normal glucose tolerance. A growing body of evidence currently suggest that the degree of hyperglycaemia upon admission and the duration of hyperglycaemia during their illness are associated with adverse outcomes. In-patient hyperglycaemia is now widely recognised as a poor prognostic marker in terms of morbidity and mortality, increased length of stay and cost to the healthcare system. Analysis of data from nine randomised controlled trials and ten observational studies reported that treatment of hyperglycaemia in non-critically ill patients was associated with reduction in the risk of infection (relative risk, 0.41;95% confidence interval, 0.21-0.77).

The current management of inpatient hyperglycaemia in non-critical care is still far from ideal, and vary widely between different centres . The discordance between clinical evidence and practice is due to a number of factors which could potentially undermine patient care and safety. Of these, hypoglycaemia remains one the biggest barriers to managing in-patient hyperglycaemia. Hypoglycaemia is associated with increased length of stay (up to 2.3 times higher) and inpatient mortality. A recent meta-analyses reported that intensive glycaemic control on non-critical care patients is associated with a trend of increased risk of hypoglycaemia. Optimal glycaemic inpatient glucose targets still remain an intensely debated subject. Consensus from the American Association of Clinical Endocrinologists (AACE) and American Diabetes Association (ADA) recommended specified targets for hospitalised patients, of fasting or pre-meal blood glucose \<7.8mmol/l and random blood glucose \<10mmol/l.

Outpatient use of real-time continuous glucose monitoring (RT-CGM) is gradually increasing. Its implementation in the outpatient setting has been supported by robust scientific and clinical studies, showing benefits in glycaemic control, minimising hypoglycaemia and improving patient experience. Extending use of RT-CGM systems to inpatient settings especially during the COVID-19 pandemic may allow hospital staff to remotely monitor glucose while reducing viral exposure through frequent patient contact and preserving personal protective equipment (PPE). RT-CGM may be of benefit to inpatients with unstable glycemia (i.e. COVID-19 patients receiving dexamethasone therapy) and at risk of severe hypoglycemia, as it can automatically alert the treating clinical team of hypo- and hyperglycemia. Use of RT-CGM in hospital could therefore potentially benefits patients by improving their glycaemic control, and healthcare professionals working in busy general ward settings by providing remote real-time glucose monitoring from the patient every 10 minutes.

The main objective of this study is to assess the efficacy of RT-CGM in maintaining glucose levels within the target range (5.6 to 10.0 mmol/l) compared to conventional glucose monitoring in hospitalised insulin-treated T2D. Other objectives include evaluating safety of RT-CGM in terms of reducing the incidence of hypoglycaemia, severe hyperglycaemia, and collecting feedback of participants and healthcare professionals using RT-CGM in the general ward settings.