Triglyceride to HDL Ratio (TG/HDL)

Q: Why is the ratio unreliable in African Americans?

Sumner and colleagues found the TG/HDL ratio did not predict clamp-measured insulin resistance in African American cohorts, so the 3.0 cut-point should not be applied in this population.

Q: What units are required?

Both inputs must be in mg/dL. If values are in mmol/L, convert triglycerides (×88.57) and HDL (×38.67) to mg/dL first.

Calculates the ratio of fasting triglycerides to HDL cholesterol. A ratio ≥ 3.0 (mg/dL units) has been used as a marker of insulin resistance in overweight non-diabetic adults. The predictive value is ethnicity-dependent and is not reliable in African American populations.

Endocrinology EndocrinologyEvidence-BasedUpdated 2026-08-16

Clinical Notes

Formula

TG/HDL ratio = Fasting triglycerides (mg/dL) ÷ HDL cholesterol (mg/dL)

Normal Range

< 3.0

Clinical Notes

In the derivation by McLaughlin and colleagues, a TG/HDL ratio ≥ 3.0 identified insulin-resistant overweight adults with high sensitivity and specificity, but this performance was not reproduced in African American cohorts.

References

McLaughlin T, et al. Ann Intern Med. 2003;139(10):802-809.
Sumner AE, et al. Diabetes Care. 2005;28(6):1433-1438.

Calculator Information

Specialty

Endocrinology

📋 Reference Ranges

Normal Range

< 3.0

Reference ranges for this calculator
Classification	Range
Low overweight non-diabetic adults (mg/dL units)	< 3.0
High overweight non-diabetic adults (mg/dL units)	≥ 3.0

What This Calculator Measures

Calculates the triglyceride to HDL ratio (TG/HDL), a lipid-based marker of insulin resistance associated with cardiometabolic risk in overweight non-diabetic adults.

How to Use

Obtain fasting triglycerides and HDL cholesterol (mg/dL).
Divide triglycerides by HDL.
A ratio ≥ 3.0 has been associated with insulin resistance in overweight non-diabetic adults.
Interpret cautiously outside this population.

Interpretation Guide

TG/HDL < 3.0 is considered low risk by this marker; ≥ 3.0 is associated with insulin resistance in overweight non-diabetic adults. The cut-point is not reliable in African American populations.

Clinical Significance

The TG/HDL ratio provides a simple, fasting lipid-based screening marker of insulin resistance, helping identify overweight adults who may benefit from metabolic risk reduction.

When to Use

Insulin resistance screening from routine lipid panels
Cardiometabolic risk assessment in overweight non-diabetic adults
Monitoring metabolic response to lifestyle intervention

When Not to Use

As a diagnostic test for insulin resistance or diabetes
In African American populations — the relationship does not hold
In patients with severe hypertriglyceridemia where the ratio is dominated by triglycerides
To predict cardiovascular events in isolation

Limitations

Ethnicity-dependent validity — unreliable in African Americans (Sumner 2005).
Derived in overweight non-diabetic adults; performance in other populations is uncertain.
Uses mg/dL units; mmol/L inputs require conversion.

Worked Example

A 50-year-old overweight woman has triglycerides 150 mg/dL and HDL 40 mg/dL.

Inputs:

triglycerides: 150

hdl: 40

TG/HDL ratio = 150 ÷ 40 = 3.75 — ≥ 3.0, associated with insulin resistance in overweight non-diabetic adults.

Evidence

Source: Original derivation (peer-reviewed)
Reference: McLaughlin T, et al. Ann Intern Med. 2003;139(10):802-809.
Reviewed By: MedCalcHub Clinical Team
Version: 1.0
Updated: 2026-08

References

McLaughlin T, Abbasi F, Cheal K, et al. Use of metabolic markers to identify overweight individuals who are insulin resistant. Ann Intern Med. 2003;139(10):802-809. (Original Derivation)
Sumner AE, et al. The triglyceride/high-density lipoprotein cholesterol ratio fails to predict insulin resistance in African-American women. Diabetes Care. 2005;28(6):1433-1438. (Level II)

Frequently Asked Questions

Why is the ratio unreliable in African Americans?

Sumner and colleagues found the TG/HDL ratio did not predict clamp-measured insulin resistance in African American cohorts, so the 3.0 cut-point should not be applied in this population.

What units are required?

Both inputs must be in mg/dL. If values are in mmol/L, convert triglycerides (×88.57) and HDL (×38.67) to mg/dL first.

Insulin resistance surrogates

TyG Index

When fasting glucose is available

HOMA-IR

When an insulin assay is available

Non-HDL Cholesterol

Lipid treatment targets

Disclaimer: This calculator is intended for educational and clinical decision support purposes only. The TG/HDL ratio is a screening marker with population limitations and must not be used alone for diagnosis.