What is the optimal triglyceride to HDL ratio?

Triglyceride to HDL Ratio: Definition and Optimal Values

The triglyceride to HDL cholesterol (TG/HDL-C) ratio is a calculated marker of insulin resistance and cardiovascular risk, with optimal values being <2.5 in women and <3.5 in men, though this ratio should be used for risk stratification rather than as a treatment target. 1, 2

Understanding the Ratio

The TG/HDL-C ratio reflects the relationship between triglyceride-rich lipoproteins and protective HDL cholesterol, providing insight into cardiovascular risk beyond traditional lipid measurements. 1

• Calculation: Simply divide the triglyceride level by the HDL cholesterol level (both in the same units - mg/dL or mmol/L). 1
• The ratio serves as a surrogate marker for insulin resistance and identifies individuals with small, dense LDL particles that are particularly atherogenic. 2, 3

Optimal and Risk Thresholds

Risk stratification cutpoints:

• Women: TG/HDL-C ratio >2.5 identifies insulin resistance and increased cardiometabolic risk. 2
• Men: TG/HDL-C ratio >3.5 identifies insulin resistance and increased cardiometabolic risk. 2
• A ratio of 0.49 suggests lower cardiovascular risk. 1

Component targets for optimal metabolic health:

• Optimal fasting triglycerides: <100 mg/dL (1.1 mmol/L). 4
• HDL cholesterol targets: ≥40 mg/dL (1.0 mmol/L) in men and ≥46 mg/dL (1.2 mmol/L) in women. 5, 1

Clinical Utility and Prognostic Value

The ratio is particularly valuable in specific populations:

• Young adults: Approximately one-third of individuals with elevated TG/HDL-C ratios are insulin resistant, even when appearing healthy. 2
• Women with suspected ischemia: The ratio is a powerful independent predictor of all-cause mortality (hazard ratio 1.95) and cardiovascular events. 3
• Men: The ratio predicts coronary heart disease, cardiovascular disease, and all-cause mortality after adjustment for established risk factors. 6
• Patients with diabetes: Those with both high triglycerides (≥150 mg/dL) and low HDL have a 1.54-fold greater risk for coronary heart disease and 2.13-fold greater risk for stroke. 7

Mortality and event prediction:

• The ratio identifies more high-risk individuals than metabolic syndrome criteria alone, though metabolic syndrome identifies those with more accentuated risk profiles. 2
• Annual incidence of type 2 diabetes is 2 times higher in men with high TG/HDL-C ratio compared to those with low ratios. 6

Critical Limitations and Interpretation Caveats

Do not use as a treatment target:

• The ratio is a risk marker only - treatment should focus on absolute LDL cholesterol goals based on cardiovascular risk category, not on improving the ratio itself. 5, 1
• For very high-risk patients: LDL <1.8 mmol/L (70 mg/dL) or at least 50% reduction. 5
• For high-risk individuals: LDL <2.5 mmol/L (100 mg/dL). 5

Ethnic and sex variations:

• The predictive value varies significantly by ethnicity - Black patients with metabolic syndrome or type 2 diabetes may not exhibit high triglyceride levels as commonly as other ethnic groups. 1
• Higher cardiovascular risks in women than men have been observed with elevated triglycerides. 1

Measurement considerations:

• Always obtain fasting lipid measurements (12-hour fast) for accurate triglyceride assessment and ratio calculation. 1
• Fasting status critically affects triglyceride levels and thus the ratio accuracy. 1
• Delay lipid assessment until acute conditions resolve to avoid misdiagnosis. 1

When the Ratio Adds Most Value

The TG/HDL-C ratio is especially useful when:

• Evaluating patients with metabolic syndrome, diabetes, or abdominal obesity where the combination of elevated triglycerides and low HDL is extremely common. 1
• Assessing cardiovascular risk in patients with elevated triglycerides, as it captures risk from atherogenic remnant particles not reflected in calculated LDL cholesterol. 5
• Screening apparently healthy young adults for insulin resistance and cardiometabolic risk. 2
• Risk stratifying women with suspected myocardial ischemia. 3

The ratio should always be interpreted as part of a complete lipid profile, not in isolation, as even with a favorable ratio, elevated absolute LDL cholesterol levels would still warrant appropriate management. 1