Background: The relationship between the percent coefficient of variation (%CV) and the risk of severe hypoglycemia (SH) or non-severe hypoglycemia (NSH) in patients with type 1 diabetes (T1D) remains to be elucidated.

Materials and methods: The Effect of Intermittent-Scanning Continuous Glucose Monitoring to Glycemic Control Including Hypoglycemia and Quality of Life of Patients with Type 1 Diabetes Mellitus (ISCHIA) study was a crossover, randomized, controlled trial for hypoglycemia prevention in patients with T1D using multiple daily injections (MDIs). Blinded continuous glucose monitoring (CGM) data of 93 patients obtained during the Control period (84 days) were used for the post hoc analysis. The receiver operating characteristics (ROC) curves were analyzed to determine the discrimination thresholds of %CV corresponding to the low blood glucose index (LBGI) > 5 and LBGI ≥ 2.5, and the occurrence of SH.

Results: The %CV corresponding to LBGI > 5 and LBGI ≥ 2.5 was 42.2% and 37.0%, respectively. The episodes of SH were observed in three patients, and the %CV corresponding to the occurrence of SH was 40.7%.

Conclusions: The identification of the discrimination threshold of %CV associated with the risk of SH or NSH in patients with T1D is needed.

Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: No potential conflicts of interest (COI) were reported by the ISCHIA Study Group relevant to this article. Potential COI concerning all individual investigators were reviewed by the Certified Review Board in accordance with the Clinical Trials Act.¹⁷ The COI of the members of the writing group are as follows: TM received lecture fees from Dexcom and Abbott and received a research grant from Medtronic. MM received lecture fees from Abbott, Eli Lilly, Novo Nordisk, and Sanofi and received a research grant from Novo Nordisk. AK received a lecture fee from Eli Lilly. MT received lecture fees from MSD, Mitsubishi Tanabe, Eli Lilly, Novo Nordisk, and Sumitomo and received subsidies from LifeScan and Takagi. YH received lecture fees from Abbott, Eli Lilly, Sanofi, Novo Nordisk, Sumitomo and Terumo received research grants from Kyowa Kirin, Medtronic, and Sumitomo and received a scholarship donation from Abbott. MO received lecture fees from Sumitomo, Eli Lilly, Novo Nordisk, Daiichi Sankyo, Ono, Mitsubishi Tanabe, Otsuka, Sanwa Kagaku Kenkyusho, Kowa, Mochida, and received subsidies from LifeScan. AT received lecture fees from Abbott, Eli Lilly, Sanofi, and Terumo. SM received lecture fees from Eli Lilly, Kowa, Sumitomo, and Novo Nordisk. JM received lecture fees from Novo Nordisk and Terumo and received a research grant from Terumo. SS, KK, YM, KN, AS, KH, and NS declare that they have no COI.