<b><i>Objective:</i></b> Estimating glucose variability (GV) through within-day
coefficient of variation (%CV<sub>w</sub>) is recommended for patients with
type-1 Diabetes (T1D). High-GV (hGV) is defined as %CV<sub>w</sub>>36%.
However, continuous glucose monitoring (CGM) devices provide exclusively total-CV
(%CV<sub>T</sub>). We aimed to assess consequences of this disparity.
<p><b><i>Research Design and Methods:</i></b> We retrospectively calculated both %CV<sub>T</sub>
and %CV<sub>W </sub>of consecutive T1D patients from their CGM raw data during
14 days. Patients with hGV
with %CV<sub>T</sub>>36% and %CV<sub>w</sub>≤36% were called the
“inconsistent-GV group”.</p>
<p><b><i>Results:</i></b> 104 patients were included. Mean %CV<sub>T</sub> and %CV<sub>w</sub> were
42.4+/-8% and 37.0+/-7.4% respectively (p<0.0001). Using %CV<sub>T</sub>, 81
patients (73.6%) were classified as hGV whereas 59 (53.6%) using %CV<sub>W </sub>(p<0.0001)
corresponding to 22 patients (21%) in the “<i>inconsistent-GV</i>
population”.</p>
<p><b><i>Conclusions:</i></b> Evaluation of GV through %CV in patients with T1D is highly
dependent on the calculation method and then must be standardized.</p>
High Glucose Variability Increases Mortality Risk in Patients with COVID-19
