Mini-review on insulin resistance assessment: Advances in surrogate indices and clinical applications

Table 1 Summary of key insulin resistance indices: Formulas, strengths, limitations, clinical applications, and references

Index	Formula	Strengths	Limitations	Typical clinical applications	Ref.
HOMA-IR	[FINS (μU/mL) × FPG (mg/dL)] ÷ 405	Simple, inexpensive, widely used; correlates with hepatic IR	Reflects mainly hepatic IR; influenced by insulin assay variability	Screening for IR; early detection of T2DM	[36,39,40]
QUICKI	1 ÷ {log [FINS (μU/mL)] + log [FPG (mg/dL)]}	Slightly more stable than HOMA-IR; correlates with HEC studies	Similar limitations to HOMA-IR; mainly reflects hepatic IR	Alternative simple index for IR estimation	[41]
Matsuda index	10000/square root of (FPG × FINS) × (Mean OGTT glucose × Mean OGTT insulin)	Assesses whole-body insulin sensitivity; captures both hepatic and peripheral IR	Requires OGTT; multiple blood samples needed	Research use; screening in high-risk populations	[42]
TyG index	ln [Fasting TG (mg/dL) × FPG (mg/dL) ÷ 2]	Easily available; useful for predicting metabolic risk	Influenced by TG variability, not a direct measure of insulin sensitivity	Prediction of MetS, T2DM, and CVD risk	[35,46-49]
TG/HDL-C ratio	Fasting TG (mg/dL) ÷ HDL-C [(mg/dL)	Simple; associated with atherogenic dyslipidemia and IR	Ethnic variability in cut-off points; limited sensitivity for early IR	CVD risk stratification; MetS screening	[50-54]

CVD: Cardiovascular disease; FINS: Fasting insulin; FPG: Fasting plasma glucose; HDL-C: High-density lipoprotein cholesterol; HEC: Hyperinsulinemic-euglycemic clamp; HOMA-IR: Homeostatic model assessment of insulin resistance; IR: Insulin resistance; MetS: Metabolic syndrome; OGTT: Oral glucose tolerance test; QUICKI: Quantitative insulin sensitivity check index; T2DM: Type 2 diabetes mellitus; TG: Triglycerides.