Hdl Large

Understanding the Role of Large HDL Particles in Cardiovascular Health

Introduction to HDL and Its Subfractions

High-density lipoprotein (HDL) particles are known for their cardioprotective roles, primarily through mechanisms such as reverse cholesterol transport and anti-inflammatory properties. However, HDL is not a uniform entity; it consists of various subfractions that differ in size, composition, and function. These subfractions include very large HDL (VL-HDL), large HDL (L-HDL), medium HDL (M-HDL), small HDL (S-HDL), and very-small HDL (VS-HDL).

Isolation and Characterization of Large HDL Particles

The isolation of HDL particles, including large HDL, can be challenging due to the overlap in size and density with other plasma proteins. A method combining sequential flotation density ultracentrifugation and size exclusion chromatography has been developed to isolate HDL particles effectively. This method allows for the separation of HDL subfractions and the identification of proteins enriched in specific HDL sizes. For instance, proteins such as lecithin cholesterol acyltransferase (LCAT) and phospholipid transfer protein (PLTP) are enriched in large HDL particles.

Large HDL Particles and Cardiovascular Risk

Large HDL particles have been shown to have a protective role against cardiovascular disease. Epidemiological studies suggest that the number of large HDL particles is inversely related to cardiovascular risk. This relationship is stronger than that observed with HDL cholesterol (HDL-C) levels alone, indicating that HDL particle number and size may be more relevant markers for cardiovascular risk assessment .

Functional Properties of Large HDL Particles

Large HDL particles, particularly HDL2, have been found to interfere with the formation of insoluble LDL-proteoglycan complexes, a key step in atherogenesis. This inhibitory effect is more pronounced in large HDL particles compared to smaller ones, suggesting a unique atheroprotective mechanism. Additionally, large HDL particles are involved in reverse cholesterol transport, a process crucial for removing excess cholesterol from peripheral tissues and transporting it to the liver for excretion.

HDL Particle Size and Composition

The size and composition of HDL particles can vary significantly among individuals and are influenced by factors such as metabolic health and hormonal changes. For example, during the menopause transition, large HDL particles and HDL size tend to decline, while small HDL particles increase. This shift is associated with changes in HDL function, such as reduced cholesterol efflux capacity per particle.

Clinical Implications and Future Directions

The clinical relevance of HDL particle size and number is becoming increasingly recognized. Large HDL particles are associated with a lower risk of coronary artery calcification and carotid intima-media thickening, both markers of atherosclerosis . These findings suggest that measuring HDL particle profiles, rather than just HDL-C levels, could improve cardiovascular risk prediction and guide therapeutic interventions.

Conclusion

Large HDL particles play a crucial role in cardiovascular health through various mechanisms, including reverse cholesterol transport and inhibition of LDL-proteoglycan complex formation. The number and size of HDL particles are emerging as important markers for cardiovascular risk assessment. Future research should focus on standardizing HDL subfraction nomenclature and developing clinical methods to measure HDL particle profiles accurately, which could lead to better cardiovascular risk prediction and targeted therapies.

Summary

Not a yes or no question

Understanding the Role of Large HDL Particles in Cardiovascular Health

Introduction to HDL and Its Subfractions

Isolation and Characterization of Large HDL Particles

Large HDL Particles and Cardiovascular Risk

Functional Properties of Large HDL Particles

HDL Particle Size and Composition

Clinical Implications and Future Directions

Conclusion

Sources and full results

Isolation of HDL by sequential flotation ultracentrifugation followed by size exclusion chromatography reveals size-based enrichment of HDL-associated proteins

HDL measures, particle heterogeneity, proposed nomenclature, and relation to atherosclerotic cardiovascular events.

Novel Pathways of Apolipoprotein A-I Metabolism in High-Density Lipoprotein of Different Sizes in Humans

HDL2 interferes with LDL association with arterial proteoglycans: a possible athero-protective effect.

HDL particle number and size as predictors of cardiovascular disease

A comparison of the theoretical relationship between HDL size and the ratio of HDL cholesterol to apolipoprotein A-I with experimental results from the Women's Health Study.

Small and medium sized HDL particles are protectively associated with coronary calcification in a cross-sectional population-based sample.

HDL (High-Density Lipoprotein) Subclasses, Lipid Content, and Function Trajectories Across the Menopause Transition: SWAN-HDL Study.

Abnormal high density lipoproteins of abetalipoproteinemia: relevance to normal HDL metabolism.

Concentration of Smaller High‐Density Lipoprotein Particle (HDL‐P) Is Inversely Correlated With Carotid Intima Media Thickening After Confounder Adjustment: The Multi Ethnic Study of Atherosclerosis (MESA)

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