Source . | Type 1, type 2, nondiabetes . | Subjects (n) . | Approximate HbA1c range (National Glycohemoglobin Standardization Program) . | Children, adults . | Length . | Method: discrete or CGM . | Curve fit (R2) . | Predict HbA1c slope (95% CI) . | Intercept (mg/dL) (95% CI) . | Range of actual mean glucose at 6.9–7.1%† . |
---|---|---|---|---|---|---|---|---|---|---|
Discrete | ||||||||||
Hempe et al. (11) | Type 1 diabetes | 128 | 6.5–18.7% | Children, adolescents, adults | Up to 2.3 years | Discrete | Linear (0.50) | 18.5* | ∼−4.8* | ∼90–235 |
Rohlfing et al. (12) | Type 1 diabetes | 1,439 | 5.3–13.3%† | Adolescents, adults | 3–9 years | Discrete 7 point quarterly | Linear (0.67) | 35.6 | −77.3 | ∼100–250 |
Makris et al. (13) | Type 2 diabetes and/or metabolic syndrome | 140 | 5.1–10.9% | Adults 41–81 years | 1 month | Discrete 6 point 12 times in a month | Linear (0.86) | 34.7 (32.5–37.0) | −79.2 | ∼127–207 |
CGM | ||||||||||
Nathan et al. (22) | Type 1 and type 2 diabetes and nondiabetes | 15, 7, and 3 | 4.6–10.2%† | Adults | 3 months | CGM | Linear (0.79) | 31.5 | −68.6 | Too few |
Wilson et al. (16) | Type 1 diabetes | 48 | 5.8–8.8%† | Children, adolescents | 6 months | CGM | Linear | 18 (14–22) | +40 | ∼138–189 |
Nathan et al. (15) | Type 1 and type 2 diabetes and nondiabetes | 268, 159, and 80 | 3.8–14.3%† | Adults | 3 months | Intermittent CGM >7 days over 3 months discrete | Linear (0.84) | 28.7 | −46.7 | ∼125–205 |
Mazze (14) | Type 1 and type 2 diabetes and nondiabetes | 124 | 4.9–10.4%† | Adults | 8–75 days | CGM | Linear (0.71) | 26.3* | −32.7* | ∼130–150 |
Current study | Type 1 diabetes | 252 | 5.1–9.7% | Children, adolescents, adults | 3-month continuous | CGM | Linear (0.63) | 24.4 (22.0−26.7) | −16.2 | 128–187 |
Source . | Type 1, type 2, nondiabetes . | Subjects (n) . | Approximate HbA1c range (National Glycohemoglobin Standardization Program) . | Children, adults . | Length . | Method: discrete or CGM . | Curve fit (R2) . | Predict HbA1c slope (95% CI) . | Intercept (mg/dL) (95% CI) . | Range of actual mean glucose at 6.9–7.1%† . |
---|---|---|---|---|---|---|---|---|---|---|
Discrete | ||||||||||
Hempe et al. (11) | Type 1 diabetes | 128 | 6.5–18.7% | Children, adolescents, adults | Up to 2.3 years | Discrete | Linear (0.50) | 18.5* | ∼−4.8* | ∼90–235 |
Rohlfing et al. (12) | Type 1 diabetes | 1,439 | 5.3–13.3%† | Adolescents, adults | 3–9 years | Discrete 7 point quarterly | Linear (0.67) | 35.6 | −77.3 | ∼100–250 |
Makris et al. (13) | Type 2 diabetes and/or metabolic syndrome | 140 | 5.1–10.9% | Adults 41–81 years | 1 month | Discrete 6 point 12 times in a month | Linear (0.86) | 34.7 (32.5–37.0) | −79.2 | ∼127–207 |
CGM | ||||||||||
Nathan et al. (22) | Type 1 and type 2 diabetes and nondiabetes | 15, 7, and 3 | 4.6–10.2%† | Adults | 3 months | CGM | Linear (0.79) | 31.5 | −68.6 | Too few |
Wilson et al. (16) | Type 1 diabetes | 48 | 5.8–8.8%† | Children, adolescents | 6 months | CGM | Linear | 18 (14–22) | +40 | ∼138–189 |
Nathan et al. (15) | Type 1 and type 2 diabetes and nondiabetes | 268, 159, and 80 | 3.8–14.3%† | Adults | 3 months | Intermittent CGM >7 days over 3 months discrete | Linear (0.84) | 28.7 | −46.7 | ∼125–205 |
Mazze (14) | Type 1 and type 2 diabetes and nondiabetes | 124 | 4.9–10.4%† | Adults | 8–75 days | CGM | Linear (0.71) | 26.3* | −32.7* | ∼130–150 |
Current study | Type 1 diabetes | 252 | 5.1–9.7% | Children, adolescents, adults | 3-month continuous | CGM | Linear (0.63) | 24.4 (22.0−26.7) | −16.2 | 128–187 |
*Study originally reported slope from a model with HbA1c as the independent variable (i.e., HbA1c = slope × mean glucose + intercept). Values were converted to equivalent slope and intercept with mean glucose as the dependent variable using the reported R2 value.
†Estimated from graphs.