Table 1.
Estimation of HbA1c for given CGM-derived TIR
| TIR (70–180 mg/dL) | Vigersky et al.a [23] (n=1,137 participants with T1DM or T2DM) | Beck et al.b [22] at baseline (n=455 participants with T1DM) | Beck et al.b [22] in month 6 (n=545 participants with T1DM) | Fabris et al.c [24] (n=168 participants with T1DM) |
|---|---|---|---|---|
| 20% | 10.6 | 9.4 | 8.8 | 9.3 |
| 30% | 9.8 | 8.9 | 8.4 | 8.9 |
| 40% | 9.0 | 8.4 | 8.0 | 8.5 |
| 50% | 8.3 | 7.9 | 7.6 | 8.1 |
| 60% | 7.5 | 7.4 | 7.2 | 7.7 |
| 70% | 6.7 | 7.0 | 6.8 | 7.3 |
| 80% | 5.9 | 6.5 | 6.4 | 6.9 |
| 90% | 5.1 | 6.0 | 6.0 | 6.5 |
| Baseline HbA1c, % | NA | 7.5±1.0 | 7.2±0.8 | NA |
| Equation | HbA1c=12.32–0.081×TIR | HbA1c=10.31–0.048×TIR | HbA1c=9.65–0.041×TIR | HbA1c=10.12–0.04×TIR |
| Every 10% increase in TIR | ~0.8% HbA1c reduction | ~0.5% HbA1c reduction | ~0.4% HbA1c reduction | ~0.4% HbA1c reduction |
HbA1c, glycosylated hemoglobin; CGM, continuous glucose monitoring; TIR, time in range; T1DM, type 1 diabetes mellitus; T2DM, type 2 diabetes mellitus; NA, not applicable.
a
Data sets were from 18 clinical trials using CGM for a minimum of 3 days,
b
Data used in analyses were from four randomized trials using CGM for a minimum of 10 days for baseline and 14 days in month 6,
c
Linear regression analysis was used to analyze 3-month full CGM data for this equation.