Understanding Average Glucose, Standard Deviation, CV, and Blood Sugar Variability

What do these numbers mean, what’s the target, and how can they provide insight into better diabetes management? Example days included!

Glucose monitoring is one of the most important tools in diabetes. Just like a speedometer in a car, glucose data helps inform key actions in diabetes – take more or less medication, change food choices or timing, exercise, and more. Most of us think of glucose data in an immediate sense for guiding therapy decisions: “How much insulin should I take right now?” However, it also helps inform longer-term patterns: “My blood sugar has been consistently high after breakfast for the past two weeks; why might that be and what can be done about it?


Source: DiaTribe


Thanks for drawing my attention to this, Mila. Since diaTribe doesn’t publish every day, I don’t always see their content the day they post.

As many of you know, I’m a data nerd when it comes to my diabetes data. It provides sustaining motivation for me and helps me devise effective counter-measures when things go wrong. I do have diabetes and things consistently go wrong. The important thing is that using data, I get back on track within a week or two instead of troubling patterns going on for months or more.

I know not everyone is motivated by numbers; I’m lucky, with having diabetes, that numbers and data make me want to do what needs to get done. I find that the mere observation of my diabetes data hooks me on a subconscious level and without even thinking much about it, it gives me the motivation to take the action that I need. It makes, for example, stopping a recently developed evening snacking habit easier for me.

Adam Brown mentions the ambulatory glucose profile (Dexcom Clarity and other software) in this piece. I’ve been using it for years. I think the 14-day AGP is the best, most concise, report that provides the basis for taking action. It is a single page report and most of the value lies in its simple graphic, once you learn how to read it.

If you don’t like numbers and data and can only muster up a limited amount of effort to absorb it, I would concentrate your effort into understanding this one basic report.

You can read more about the AGP report at the link below.


More detailed original study publication about the AGP in 2013.