<prompt> Hemoglobin which has diagnostic value in diabetes mellitus?HbAHbFHbA1HbS  <response>: Glycated haemoglobin provides an accurate and objective measure of glycaemic control over a period of weeks to months. In diabetes, the slow non-enzymatic covalent attachment of glucose to haemoglobin glycation increases the amount in the HbA1 HbA1c fraction relative to non-glycated adult haemoglobin HbA0. These fractions can be separated by chromatography; laboratories may report glycated haemoglobin as total glycated haemoglobin GHb, HbA1 or HbA1c. In most countries, HbA1c is the preferred measurement. Davidson Ed 23 Pg 726 