Table 1 The metrics and measure of GV

Long-term GV

 CV

Variation around the mean blood glucose of HbA1c, FPG and PPG between sequential visits

[19]

 SD

Magnitude of variability relative to mean blood glucose of HbA1c, FPG and PPG between sequential visits

[19]

 VIM

Based on logarithmic curve fitting (the natural logarithm of SD over the natural logarithm of the mean)

[22]

Short-term GV

 Within-day or between-day GV

  CV

Variation around the mean blood glucose

[18]

  SD

Magnitude of variability relative to mean blood glucose

[18]

  LBGI/HBGI

Measure of frequency and magnitude of hypoglycemia or hyperglycemia

[31]

  ADRR

Sum of the daily peak risks for hypoglycemia and hyperglycemia

[32]

 Within-day GV

  MAGE

Mean differences from peaks to nadirs

[23]

  MAG

Absolute differences between sequential readings divided by the time

[8]

  CONGA

Difference between a current blood glucose reading and a reading taken hours earlier

[25]

  TIR

Percentage of time spent within the target glucose range of 3.9–10.0 mmol/L during a 24-h period

[26, 27]

 Between-day GV

  MODD

Absolute differences between two glucose values measured at the same time with a 24 h interval

[28]

  AGP/IQRs

Distribution of glucose data at a given timepoint

[29, 30]

 Measuring method of GV

  SMBG

Reflected blood glucose fluctuations on the timescale of hours or days

[20]

  CGM

Interstitial glucose measurements at 5 min intervals

[20, 34]

  Flash glucose monitoring

Measured interstitial glucose and indicated direction and speed of glucose change

[36]