Myths and methodologies: Assessing glycaemic control and associated regulatory mechanisms in human physiology research.

Accurate measurements of glycaemic control and the underpinning regulatory mechanisms are vital in human physiology research. Glycaemic control is the maintenance of blood glucose concentrations within optimal levels and is governed by physiological variables including insulin sensitivity, glucose tolerance and β-cell function. These can be measured with a plethora of methods, all with their own benefits and limitations. Deciding on the best method to use is challenging and depends on the specific research question(s). This review therefore discusses the theory and procedure, validity and reliability and any special considerations of a range common methods used to measure glycaemic control, insulin sensitivity, glucose tolerance and β-cell function. Methods reviewed include glycosylated haemoglobin, continuous glucose monitors, the oral glucose tolerance test, mixed meal tolerance test, hyperinsulinaemic euglycaemic clamp, hyperglycaemic clamp, intravenous glucose tolerance test and indices derived from both fasting concentrations and the oral glucose tolerance test. This review aims to help direct understanding, assessment and decisions regarding which method to use based on specific physiology-related research questions.