Latest article: Prediabetes and type 2 diabetes mellitus: Improving glycaemic control and metabolic outcomes

Glucose, obtained through the breakdown of carbohydrates and proteins, is the body’s principal fuel, essential for the proper functioning of every organ.¹ At the cellular level, glucose is usually the final substrate that enters the tissue cells and converts to adenosine triphosphate (ATP), the primary energy currency of the cell. The amount of glucose utilisation is influenced by the rate of insulin secretion from the pancreas and the sensitivity of the cells to insulin. Having good blood glucose balance is essential for overall health; however, conditions such as prediabetes and type 2 diabetes mellitus (T2DM) are associated with poor glucose homeostasis.^2,3

THE DEFINITIONS AND PREVALENCE OF PREDIABETES AND T2DM

Prediabetes is a metabolic condition in which the criteria for diabetes are not met, although it is characterised by impaired fasting glucose, impaired glucose tolerance and/or elevated glycated haemoglobin (HbA1c).^4,5

In 2019, the global prevalence of prediabetes was estimated as 7.5%, which is projected to reach 8.6% by 2045.⁶ Without effective intervention, 5% to 10% of people with prediabetes progress to T2DM every year.⁷ Moreover, people with prediabetes are at greater risk of a range of health conditions, such as cardiovascular disease, chronic kidney disease, cancer and dementia.^4,8 In a recent review, it was demonstrated that every decade of earlier diagnosis of T2DM was associated with approximately 3 to 4 years of lower life expectancy.⁹ This means that a diagnosis of T2DM at age 30 could be associated with a reduced life expectancy of up to 14 years.

Although definitions of prediabetes and T2DM vary, it is generally identified based on fasting venous blood glucose levels, blood glucose levels two hours after a 75 g oral glucose tolerance test (OGTT) and/or a HbA1c test.^4,5 The criteria published in a position statement on the screening and management of prediabetes in adults in Australia are detailed in Table 1.