*Geek Box: Glycaemic Measures of AUC and the MAGE

*Geek Box: Glycaemic Measures of AUC and the MAGE

The “area under the curve” [AUC] is a mathematical calculation that provides a measure of the total exposure to a compound in circulation. For example, if you measure blood glucose every 30mins in the 2-hours after a meal, this gives you 4 values. Each of those values alone doesn’t give you a measure of the total exposure to blood glucose over that timeframe, because they are single values, when at any given time-point blood glucose was elevated and changing minute-to-minute.

Therefore, to capture the full exposure over the entire 2-hour period, AUC calculations can be used for different measures, whether glucose, insulin, free-fatty acids, or perhaps a supplement. Rather than just have the concentration measured at specific times, you now have the full concentration of the whole time period over which the measures were taken. The “incremental” version of AUC simply means that any values below the baseline/fasting measurement are not included in the calculation.

The MAGE [Mean Amplitude of Glycaemic Excursions] is a measure of glycaemic variability, i.e., between-day and withing-day glycaemic excursions, which are derived from continuous glucose monitors [CGMs]. Specifically, the MAGE represents mealtime-related glucose excursions defined as glucose levels 1-standard deviation above or below the 24 h average minimum or maximum glucose level, respectively.