Aims/Introduction
Flash and continuous glucose monitoring systems are becoming prevalent in clinical practice. We directly compared a flash glucose monitoring system (FreeStyle Libre Pro
[FSL
‐Pro]) with a continuous glucose monitoring system (
iP
ro2) in patients with diabetes mellitus.
Materials and Methods
Glucose concentrations were simultaneously measured using the
FSL
‐Pro,
iP
ro2 and self‐monitoring blood glucose in 10 patients with diabetes mellitus, and agreement among them was assessed.
Results
Parkes error grid analysis showed that the 92.9 and 7.1% of glucose values measured using the
FSL
‐Pro fell into areas A and B, respectively, and that 96.3, 2.8 and 0.9% of those determined using
iP
ro2 fell into areas A, B and C, respectively. The median absolute relative differences compared with self‐monitoring blood glucose were 8.1% (3.9–12.7%) and 5.0% (2.6–9.1%) for the
FSL
‐Pro and
iP
ro2, respectively. Analysis of 5,555 paired values showed a close correlation between
FSL
‐Pro and
iP
ro2 glucose values (ρ = 0.96,
P
< 0.01). Notably, 65.3% of all glucose values were lower for the
FSL
‐Pro than the
iP
ro2. Median glucose values also decreased by 3.3% for the
FSL
‐Pro compared with the
iP
ro2 (177.0 [133.0–228.0] vs 183.0 [145.0–230.0] mg/dL,
P
< 0.01). The difference in glucose values between the two systems was more pronounced in hypoglycemia. The median absolute relative difference between
FSL
‐Pro and
iP
ro2 during hypoglycemia was much larger than that during euglycemia and hyperglycemia.
Conclusions
Both the
FSL
‐Pro and
iP
ro2 systems are clinically acceptable, but glucose values tended to be lower when measured using the
FSL
‐Pro than the
iP
ro2. Agreement was not close between these systems during hypoglycemia.