Estimated Glucose Disposal Rate (eGDR) Calculator
Estimated Glucose Disposal Rate (eGDR) Calculator
Estimate insulin sensitivity in type 1 diabetes from waist circumference, hypertension and HbA1c — the surrogate derived and validated in that population.
Estimated Glucose Disposal Rate (eGDR)
Type 1 diabetes onlyWaist circumference 95 cm, no hypertension, HbA1c 7.5%
Formula
- WC
- waist circumference, cm
- HTN
- 1 if treated hypertension or blood pressure ≥ 140/90, otherwise 0
- HbA1c
- %, DCCT-aligned
- result
- mg/kg/min — an estimate of the glucose disposal rate measured directly by a euglycaemic clamp
Worked example
Waist circumference 95 cm, no hypertension, HbA1c 7.5%
0.09 × 95 = 8.55
0.551 × 7.5 = 4.1325
21.158 − 8.55 − 0 − 4.1325 = 8.48 mg/kg/min
eGDR bands
| eGDR (mg/kg/min) | Interpretation |
|---|---|
| Below 4 | Marked insulin resistance |
| 4 – 6 | Moderate insulin resistance |
| 6 – 8 | Mild insulin resistance |
| Above 8 | Insulin sensitive |
Derived in type 1 diabetes — do not extend it to type 2
eGDR was derived in the Pittsburgh Epidemiology of Diabetes Complications (EDC) study, a cohort of people with type 1 diabetes, and validated there against directly measured glucose disposal rate from euglycaemic-hyperinsulinaemic clamp studies. Every coefficient in the equation reflects relationships fitted in that population. Applying it to type 2 diabetes is off-label: the equation was never fitted on that population, insulin resistance behaves differently when endogenous insulin secretion is preserved, and there is no validation supporting its use there. State this plainly to anyone using the tool rather than letting it be assumed.
Within type 1 diabetes, a low eGDR identifies what has been termed ‘double diabetes’ — the coexistence of autoimmune beta-cell failure with the acquired insulin resistance more typically associated with type 2 diabetes. This combination is not rare: rising rates of overweight and obesity in people with type 1 diabetes mean a meaningful proportion now carry significant insulin resistance on top of their absolute insulin deficiency.
The clinical significance is substantial. In the EDC cohort and in subsequent studies, a low eGDR independently predicted cardiovascular disease, diabetic nephropathy and mortality, over and above glycaemic control alone. It captures something HbA1c alone does not: the metabolic burden of insulin resistance layered on top of type 1 diabetes, which carries its own prognostic weight.
Frequently asked questions
Can eGDR be used in type 2 diabetes?
No. It was derived and validated exclusively in the Pittsburgh EDC cohort of people with type 1 diabetes. Its coefficients were never fitted for type 2 diabetes, and using it there is off-label.
What does a low eGDR mean in type 1 diabetes?
It indicates significant insulin resistance layered on top of the autoimmune insulin deficiency of type 1 diabetes — sometimes called ‘double diabetes’ — and independently predicts cardiovascular disease, nephropathy and mortality.
What inputs does eGDR use?
Waist circumference, whether the person has treated hypertension or a blood pressure of 140/90 or higher, and HbA1c. No insulin measurement is required.
How was eGDR validated?
Against glucose disposal rate measured directly by euglycaemic-hyperinsulinaemic clamp studies in the Pittsburgh Epidemiology of Diabetes Complications cohort.
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References
- Williams KV et al. Can clinical factors estimate insulin resistance in type 1 diabetes? Diabetes. 2000;49(4):626–32.
- Nyström T et al. Estimated glucose disposal rate predicts mortality in adults with type 1 diabetes. Diabetes Obes Metab. 2018;20(3):556–63.