Small Dense Low-Density Lipoprotein Subfraction 2

sdLDL-2 is a harmful, small form of "bad" cholesterol that increases the risk of heart disease when levels are high.

📋 About This Biomarker

Small Dense LDL 2 (sdLDL-2) is a type of "bad" cholesterol particle that falls within the smallest and densest range of LDL cholesterol. While all LDL types carry cholesterol through the blood, small dense LDL particles are much more dangerous than larger ones. They’re tiny enough to easily penetrate the walls of your arteries, where they can become trapped and lead to plaque build-up, which increases the risk of heart disease and stroke. sdLDL-2, in particular, is considered more harmful than the larger LDL particles (like LDL 1 or Mid A) because it’s more likely to become oxidised, which triggers inflammation and artery damage. These particles tend to rise in people with insulin resistance, type 2 diabetes, metabolic syndrome, or diets high in sugar and processed foods. Understanding your level of sdLDL-2 gives a clearer picture of your cardiovascular health - even if your total LDL is normal. It’s like identifying which specific passengers in a crowd are most likely to cause trouble.

🎯 Why We Test This

Testing sdLDL-2 provides deeper insight into your heart health than standard cholesterol tests. It can reveal hidden cardiovascular risk, especially in people who appear healthy on regular blood tests but have metabolic conditions or a family history of heart disease. Identifying high sdLDL-2 early means you can take steps to prevent long-term complications.

⚠️ What Affects It

sdLDL-2 levels increase with high sugar and carbohydrate intake, especially from processed foods. A lack of physical activity, excess abdominal fat, insulin resistance, and diabetes all increase the production of these smaller LDL particles. Other factors include genetics, smoking, stress, and low levels of HDL ("good cholesterol"). Hormonal changes such as menopause can also affect LDL particle size.

📈 How to Improve

If sdLDL-2 is high or near the high end, aim to reduce processed foods, sugar, and alcohol, and increase healthy fats, fibre, and physical activity. These changes help shift your cholesterol profile toward larger, safer LDL particles. If sdLDL-2 is low or near the low end, you’re in a strong position - keep up your current lifestyle habits to maintain that protection.

📊 Understanding Your Results (mmol/L)

Low (< 0 mmol/L)
Very low sdLDL-2 levels are usually a great sign. It means your blood is carrying cholesterol in larger, less harmful particles. This result is typical in people with a healthy metabolism, balanced diet, and low inflammation, and is not typically a concern.
Optimal (0 - 0.25 mmol/L)
When sdLDL-2 levels fall within the healthy range, this suggests a lower presence of small, dense LDL particles - a good indicator for cardiovascular health. It means your body is mostly producing larger, less harmful LDL particles.
High (> 0.25 mmol/L)
Higher levels of sdLDL-2 indicate an increased number of the most harmful LDL particles in the bloodstream. This is a strong warning sign for cardiovascular disease risk, as these particles are more likely to cause artery blockages, inflammation, and contribute to atherosclerosis (hardening of the arteries). Action should be taken to reduce these levels through lifestyle and possibly medical interventions.
Also known as: Small Dense LDL 2, sdLDL-2