Guide to LDL/HDL Ratio

WRITTEN BY

The Levels Team

Updated: 05/22/2025|12 min read

Summary

The LDL/HDL ratio describes the balance between cholesterol being deposited in tissues (LDL) versus cholesterol being removed from tissues (HDL).

Why It Matters

The LDL/HDL ratio compares your damaging cholesterol (LDL) to your protective cholesterol (HDL). HDL collects excess cholesterol from your blood vessels and tissues and transports it back to your liver for disposal. LDL deposits cholesterol in your arteries, which can lead to plaque buildup and a higher risk of heart disease. 

The value of the ratio is that individual cholesterol numbers---especially total cholesterol--- might be misleading. For example, someone might have moderately high LDL but also high HDL, resulting in a better ratio and lower risk than someone with lower LDL but very low HDL.

A high ratio can indicate a greater risk of heart disease. However, evidence suggests that other ratios, such as total cholesterol/HDL, ApoB/ApoA-I, triglycerides/HDL, and non-HDL cholesterol, might be more predictive of cardiovascular risk. For instance, the ratio doesn't tell us about particle size or number---two people could have the same ratio but very different actual risks based on whether their LDL particles are predominantly large (pattern A) or small and dense (pattern B). It's best to consider the full cardiovascular panel in assessing risk and treatment. 

Clinical Ranges

Female

• Below Average Risk: <2.34 (calc)

Male

• Below Average Risk: <2.28 (calc)

Lifestyle Factors That Can Impact It

Factors that may contribute to a low (healthier) ratio:

• Regular aerobic exercise simultaneously increases HDL production and enhances LDL clearance through improved metabolic function.
• The Mediterranean diet is rich in monounsaturated fats and fiber that help lower LDL while supporting HDL function.
• Adequate sleep (7-9 hours per night) supports proper hormone regulation that maintains healthy cholesterol metabolism.
• Stress management reduces levels of cortisol, which can disrupt lipid metabolism.
• Weight management helps maintain insulin sensitivity, which supports proper cholesterol processing.
• Fiber binds to cholesterol in the digestive tract, reducing LDL absorption while supporting HDL function.
• Regular meals (time between meals) help maintain stable insulin levels that regulate cholesterol metabolism.

Factors that may contribute to a high (unhealthy) ratio:

• Smoking damages HDL particles while increasing inflammation that oxidizes LDL.
• High-sugar and high-refined-carbohydrate diet can trigger insulin spikes that increase LDL production while suppressing HDL.
• Trans fats simultaneously raise LDL and lower HDL through direct effects on liver metabolism.
• Excessive alcohol use disrupts liver function, affecting both cholesterol production and clearance.
• Processed foods often combine multiple unhealthy elements (sugars, trans fats, refined carbs) that adversely affect both LDL and HDL.
• Chronic stress elevates cortisol and inflammatory markers that disrupt normal cholesterol metabolism.

Other Factors That Can Impact It

Medications

• Statins and other cholesterol-lowering medications like ezetimibe, bempedoic acid, PCSK 9inhibitors, and bile acid sequestrants: improves ratio by reducing LDL and increasing HDL
• Fibrates: improves ratio by affecting both LDL and HDL
• Beta-blockers: can worsen ratio by lowering HDL
• Birth control: may worsen ratio
• Anabolic steroids: can worsen ratio
• Diabetes medications: may improve ratio

Supplements

• Fish oil: may worsen ratio by raising LDL more than HDL
• Niacin: may improve ratio by raising HDL and lowering triglycerides
• Red yeast rice: can improve ratio by lowering LDL similar to statins
• Plant sterols: can improve ratio by lowering LDL absorption from food
• Berberine: may improve ratio through multiple mechanisms

Hormones

• Thyroid hormones: affect cholesterol metabolism
• Estrogen: generally improves ratio
• Testosterone: can affect ratio either way
• Cortisol: may worsen ratio
• Growth hormone: can affect lipid metabolism

Testing Accuracy and Stability

HDL measurements tend to be very reliable, but LDL is often calculated rather than directly measured. Fasting state can affect accuracy of test results and there is some individual fluctuation day-to-day. For these reasons, it's best to look at patterns over time in assessing risk.

Factors That Can Affect the Accuracy of Your Test

• Not fasting for 9--12 hours before the test can affect your results.
• Moderate exercise within 24 hours of the test can temporarily improve the ratio, while overly strenuous exercise can worsen it.
• A recent illness can cause the ratio to increase due to the effects of inflammation on cholesterol.
• Chronic stress can worsen the ratio by leading to lower levels of HDL and higher levels of LDL.
• Gaining significant weight can worsen the ratio by lowering your HDL and increasing your LDL.
• Taking certain medications (such as beta-blockers, diuretics, and steroids) before the test can affect the results.
• The ratio can be higher during the winter due to changes in diet, reduced physical activity, and less vitamin D absorption.
• Hormone fluctuations during the menstrual cycle (particularly estrogen) can affect the ratio.

How it Relates to Other Markers

• High ratio with high triglycerides: May suggest insulin resistance with high risk of cardiovascular disease, particularly concerning.
• High ratio with normal triglycerides: May indicate genetic factors or metabolic dysfunction.
• Normal ratio with high ApoB: Can be a hidden risk; particle number may be high despite reasonable ratio.
• Low ratio with high inflammatory markers: May still indicate cardiovascular risk despite a favorable ratio.

Follow-up Considerations

You should always speak to your doctor if you have medical questions or before making medical decisions.

When Re-Testing May Be Appropriate

• Moderate risk: Quarterly testing while implementing lifestyle changes
• High risk: Immediate repeat testing to confirm, then frequent monitoring as directed by a specialist

Additional Testing Your Doctor May Consider

• Carotid artery ultrasound
• Calcium scoring
• Advanced lipoprotein testing (VAP)
• LDL particle size testing
• Cardiac stress test if indicated
• Genetic testing for familial hypercholesterolemia if suspected

When Additional Care May Be Warranted

• Moderate risk: If ratio doesn't improve after 3-6 months of lifestyle changes
• High risk: Consider cardiology referral, may need intervention.

Bibliography