Metabolic health

Triglyceride-glucose index (TyG index)

TyG

Included in Baseline and Complete.

An emerging estimate of insulin resistance.

The TyG index is calculated from your fasting triglyceride and fasting glucose results. Researchers use it as an inexpensive stand-in for insulin resistance, which is otherwise hard to measure directly.

A simple formula estimates something hard to measure.

The most accurate test of insulin resistance, called a clamp study, is mostly limited to research settings. The TyG index instead combines fasting triglycerides and fasting glucose, two results that tend to rise as insulin resistance develops, in a short formula. The formula uses US units, so Canadian results are converted first.

Research on the TyG index is still developing. Reviews find it tracks insulin resistance reasonably well and is associated with cardiovascular disease, but studies use different cut-offs, so there's no standard target. It's best treated as a supportive marker alongside standard tests.

The TyG index is a low-cost estimate that's still being studied.

Questions

Why does fasting matter for the TyG index?

Triglycerides and glucose both rise after a meal, so the index was designed around fasting results. A non-fasting sample can make it look higher than it really is. If you ate before your draw, let your clinician know.

What does a higher TyG index mean?

A higher value may suggest insulin resistance, which is linked with type 2 diabetes and heart disease. It's one input, read together with your HbA1c, waist, blood pressure, and cholesterol results, and it can be rechecked over time.

Sources and references