Diabetes: glycaemic control in type 2 (drug treatments)

Overview

The term diabetes mellitus encompasses a group of disorders characterised by chronic hyperglycaemia with disturbances of carbohydrate, fat, and protein metabolism resulting from defects of insulin secretion, insulin action, or both. Type 2 diabetes is the most common form of diabetes, and defects of both insulin action and insulin secretion are usually present by the time of diagnosis. WHO recognises diabetes as a progressive disorder of glucose metabolism in which individuals may proceed from normoglycaemia (fasting plasma venous glucose <5.5 mmol/L), impaired glucose tolerance (fasting plasma venous glucose <7.0 mmol/L and plasma glucose between 7.8 mmol/L and 11.1 mmol/L 2 hours after a 75 g oral glucose load, the oral blood glucose tolerance test [OGTT]), impaired fasting glycaemia (fasting venous plasma glucose between 5.6 mmol/L and 7.0 mmol/L), and diabetes.[1] As a consequence of the inability of the body to use glucose as an energy source, blood glucose levels rise and symptoms such as thirst, polyuria, blurring of vision, or weight loss may develop. Diagnosis: Since 1965, WHO has published guidelines for the diagnosis and classification of diabetes. In 2006, WHO decided that the diagnostic criteria should be maintained.[1] In the presence of symptoms, diabetes may be diagnosed on the basis of a single random elevated plasma glucose (11.1 mmol/L or more). In the absence of symptoms, the diagnosis should be based on blood glucose results in the diabetes range taken at different time points, either from a random sample, or fasting (plasma blood glucose 7.0 mmol/L or more), or from the OGTT (plasma blood glucose 11.1 mmol/L or more 2 hours after a 75 g glucose load).[1] Population: For the purpose of this review, we have excluded pregnant women and acutely unwell adults (e.g., after surgery or MI), and people with secondary diabetes (e.g., those with hyperglycaemia based on temporal use of corticosteroids).