Time in tight range and time in range for predicting the achievement of typical glucose management indicator and HbA1c targets.

AIMS/HYPOTHESIS This study aimed to compare the ability of time in tight range (TITR) and time in range (TIR) to predict the achievement of typical glucose management indicator (GMI) and HbA1c targets. METHODS This cross-sectional analysis included 773 adults with diabetes receiving insulin therapy who visited Samsung Medical Center between June 2019 and December 2023 and wore a Dexcom G6 or FreeStyle Libre continuous glucose monitor for at least 90 days (sensor wear time, ≥70%). A receiver operating characteristic analysis was used to compare the ability of TITR and TIR to predict GMI and HbA1c targets. RESULTS TITR had significantly greater AUC values than TIR for predicting GMIs of <53 mmol/mol (7.0%) and <48 mmol/mol (6.5%) among participants using a Dexcom G6 or FreeStyle Libre continuous glucose monitor. TITR also had significantly greater AUC values than TIR for predicting HbA1c levels of <53 mmol/mol (7.0%) (95% CI for difference: 0.006, 0.03) and <48 mmol/mol (6.5%) (95% CI for difference: 0.001, 0.03) among participants using the FreeStyle Libre. In the HbA1c range of 48-53 mmol/mol (6.5-7.0%), TIR exhibited broader variations than TITR across CV groups. The modifying effect of CV on the association between TITR and GMI or HbA1c was minimised around a GMI and HbA1c level of 53 mmol/mol (7.0%). CONCLUSIONS/INTERPRETATION TITR might be a more useful indicator than TIR of the achievement of typical GMI and HbA1c targets among adults with diabetes on insulin therapy.