Glucose Variability

Glucose variability describes how much your glucose moves around its own average over a day. It is usually reported as a standard deviation in the same units as your readings, or as a coefficient of variation, which is that standard deviation expressed as a percentage of the mean.

It matters because an average hides the shape of a day completely. Two days can average the same figure, one spent close to that figure throughout and the other swinging between a morning low and an afternoon spike, and the second is both harder to live with and associated with worse outcomes.

A coefficient of variation at or below 36 percent is the figure usually quoted as stable. Large swings most often trace back to specific meals, to the timing of exercise, or to medication, which makes variability one of the more actionable glucose measures once you can see which days are worst.

What it is not

It is not a substitute for knowing your average or your time in range; it is the third of the three, and each answers something the others cannot. It also needs frequent readings to mean anything, so it is a continuous monitor measure rather than a finger stick one.

Where you see it in FitnessSyncer

Your glucose readings are charted on your Dashboard where the spread over a day is visible directly, and the built-in Diabetes report brings the average, the variability and the time in range together. The Daily Analyzer puts a day's readings beside what you ate.