Estimate of A1C for a given TIR level based on type 1 diabetes and type 2 diabetes studies
| Beck et al. (26) (n = 545 participants with type 1 diabetes) | Vigersky and McMahon (27) (n = 1,137 participants with type 1 or type 2 diabetes) | |||
|---|---|---|---|---|
| TIR 70–180 mg/dL (3.9–10.0 mmol/L) | A1C, % (mmol/mol) | 95% CI for predicted A1C values, % | TIR 70–180 mg/dL (3.9–10.0 mmol/L) | A1C, % (mmol/mol) |
| 20% | 9.4 (79) | (8.0, 10.7) | 20% | 10.6 (92) |
| 30% | 8.9 (74) | (7.6, 10.2) | 30% | 9.8 (84) |
| 40% | 8.4 (68) | (7.1, 9.7) | 40% | 9.0 (75) |
| 50% | 7.9 (63) | (6.6, 9.2) | 50% | 8.3 (67) |
| 60% | 7.4 (57) | (6.1, 8.8) | 60% | 7.5 (59) |
| 70% | 7.0 (53) | (5.6, 8.3) | 70% | 6.7 (50) |
| 80% | 6.5 (48) | (5.2, 7.8) | 80% | 5.9 (42) |
| 90% | 6.0 (42) | (4.7, 7.3) | 90% | 5.1 (32) |
| Every 10% increase in TIR = ∼0.5% (5.5 mmol/mol) A1C reduction | Every 10% increase in TIR = ∼0.8% (8.7 mmol/mol) A1C reduction | |||
The difference between findings from the two studies likely stems from differences in number of studies analyzed and subjects included (RCTs with subjects with type 1 diabetes vs. RCTs with subjects with type 1 or type 2 diabetes with CGM and SMBG).