This calculator is for general information and education. It is not medical advice and does not replace the judgment of a doctor, nurse or pharmacist who knows the full clinical picture.
A simple marker of insulin resistance
Insulin resistance means the body needs more insulin than normal to keep blood sugar in check. The reference test, the hyperinsulinemic-euglycemic clamp, is a research procedure, and HOMA-IR needs a fasting insulin level that is not always measured. The triglyceride-glucose (TyG) index uses two routine fasting tests instead.
The formulas
- TyG = ln(fasting triglycerides (mg/dL) × fasting glucose (mg/dL) ÷ 2)
- TyG-BMI = TyG × BMI
- Atherogenic index of plasma (AIP) = log10(triglycerides ÷ HDL cholesterol), both in mmol/L
To convert triglycerides from mg/dL to mmol/L, divide by 88.57; for HDL cholesterol, divide by 38.67.
Example
Fasting triglycerides of 150 mg/dL and glucose of 100 mg/dL give TyG = ln(150 × 100 ÷ 2) = ln(7,500) = 8.92. With an HDL of 45 mg/dL, the AIP is 0.163, and with a BMI of 27 the TyG-BMI is 241.
Interpreting the TyG index
There is no single universal cut-off: studies report thresholds between about 8.5 and 8.8 depending on the population, age and sex.
| TyG | Usual reading |
|---|---|
| under 8.5 | Insulin resistance unlikely |
| 8.5 to 8.8 | Borderline |
| above 8.8 | Consistent with insulin resistance |
| AIP | Cardiovascular risk category |
|---|---|
| under 0.11 | Low |
| 0.11 to 0.21 | Intermediate |
| above 0.21 | High |
Why it is useful
The TyG index correlates well with clamp measurements and has been linked in large cohorts to the risk of type 2 diabetes, fatty liver disease and cardiovascular events. It costs nothing extra, since triglycerides and glucose are part of a standard fasting panel.
Limits
- Both tests must be fasting (8 to 12 hours); a meal raises triglycerides.
- Very high triglycerides from genetic disorders inflate the index.
- It is a screening marker, not a diagnosis: diabetes is diagnosed with fasting glucose, HbA1c or a glucose tolerance test.
Weight loss, regular exercise and fewer refined carbohydrates and alcoholic drinks lower both triglycerides and glucose, and therefore the TyG index.