The relationship between hypoglycaemia and day-to-day variability of glycaemic control has not been well established.
A post hoc analysis was performed correlating day-to-day variability of fasting SMBG with hypoglycaemia in two double-blind, treat-to-target, crossover trials that compared insulin degludec once daily (OD) with insulin glargine 100 units/mL OD in adults with T1D (SWITCH 1, n=501) or insulin-experienced adults with T2D (SWITCH 2, n=721). Available SMBG measurements were used to determine a weekly variance for each patient, using the log SMBG values to allow for relative comparisons. For each patient and treatment, the geometric mean of the weekly variance was calculated and these values were categorised into low, medium and high tertiles as a measure for day-to-day variability. The effect of having low or high variability compared with medium variability was analysed in relation to overall symptomatic (severe or blood glucose [<3.1 mmol/L] confirmed), nocturnal symptomatic (00:01–05:59), and severe (requiring third-party assistance and confirmed by a blinded adjudication committee) hypoglycaemia.
Day-to-day SMBG variability was a significant predictor for the risk of overall and nocturnal hypoglycaemia in T1D and T2D, and severe hypoglycaemia in T1D (Table).
In conclusion, day-to-day glycaemic variability relates to hypoglycaemia risk.
Table: Effect of fasting SMBG variability on hypoglycaemia in SWITCH 1 and 2: low and high tertiles compared with medium tertiles.