Modeling hepatic insulin sensitivity during a meal: validation against the euglycemic hyperinsulinemic clamp

Area of Science:

• Metabolic Physiology
• Endocrinology
• Quantitative Biology

Background:

• Endogenous glucose production (EGP) suppression post-meal is crucial for glucose homeostasis.
• Existing models link EGP suppression to glucose dynamics and insulin action.
• Hepatic insulin sensitivity (S(I)(Lmeal)) derived from meal EGP models needs validation against clamp-derived sensitivity (S(I)(Lclamp)).

Purpose of the Study:

• To compare hepatic insulin sensitivity estimated from a meal EGP model (S(I)(Lmeal)) with that from a hyperinsulinemic-euglycemic clamp (S(I)(Lclamp)).
• To validate a previously proposed EGP model using meal data and tracer techniques.

Main Methods:

• Sixty-two subjects with varying glucose tolerance underwent a triple-tracer mixed meal test.
• Fifty-seven subjects also completed a labeled euglycemic hyperinsulinemic clamp.
• Endogenous glucose production (EGP) was quantified using the tracer-to-tracee clamp technique, and the EGP model was fitted to individual data.

Main Results:

• The EGP model demonstrated a satisfactory fit to meal data, allowing precise estimation of S(I)(Lmeal).
• A good correlation (r=0.72, P<0.001) was observed between S(I)(Lmeal) and S(I)(Lclamp).
• S(I)(Lmeal) was significantly lower than S(I)(Lclamp), potentially due to differing insulin/glucose dynamics and steady-state conditions.

Conclusions:

• The EGP model provides a reliable estimate of hepatic insulin sensitivity during a meal, comparable to clamp-derived values.
• This meal-based approach offers a practical method for assessing hepatic insulin sensitivity in individuals.
• Integration with minimal models may allow S(I) estimation from single-tracer labeled meals or oral glucose tolerance tests.