LDL Medium

Lipoprotein Subfraction Disorders:

This test measures the number of particles in each of the 8 LDL subclasses. Six of these 8 subclasses are small LDL subclass particles. These smaller particles are associated with rapid uptake into the endothelium contributing to accelerated atherosclerosis.

There is a 1.3-fold increased risk for Cardiovascular diseases associated with the small LDL trait and a 1.4-fold increased risk with the medium LDL trait.

Contributing Factors:

Genetics/demographics:

- Genetic predisposition

- High triglyceride and low HDL-C levels

Lifestyle:

- High consumption of simple carbohydrates

- Overweight or obese

- Sedentary lifestyle

Illness:

- Insulin resistance/diabetes mellitus/ metabolic syndrome

Drugs:

- Nonselective beta blockers

Treatment Considerations:

Dietary/lifestyle intervention:

- Avoid simple carbohydrate diet

- Fat weight loss

- Regular exercise

- Omega-3 fish oil

Pharmacological intervention:

- Thiazolidinediones

- Nicotinic acid

- Fibrates

- Statins (minor effect. effect is specific to atorvastatin)

Disease intervention:

- Consider evaluation of cardiometabolic function

- Noninvasive imaging

- Additional blood tests

- Identify and correct insulin resistance

- Control diabetes mellitus

References:

Mann DL, Zipes DP, Libby P, Bonow RO. Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine. 10th ed: Saunders. 2015.

Hoogeveen RC, Gaubatz JW, Sun W, et al. Small dense low-density lipoprotein-cholesterol concentrations predict risk for coronary heart disease: The Atherosclerosis Risk In Communities (ARIC) study. Arterioscler Thromb Vasc Biol. 2014;34:1069-1077.

Krauss RM. Dietary and genetic effects on low-density lipoprotein heterogeneity. Annu Rev Nutr. 2001;21: 283-295.

Iacobellis G. Obesity and Cardiovascular Disease: Oxford University Press. 2009.

Slentz CA, Houmard JA, Johnson JL, et al. Inactivity, exercise training and detraining, and plasma lipoproteins. STRRIDE: a randomized, controlled study of exercise intensity and amount. J Appl Physiol (1985). 2007;103:432-442.

Campos H, Genest JJ, Jr., Blijlevens E, et al. Low density lipoprotein particle size and coronary artery disease. Arterioscler Thromb. 1992;12:187-195.

Griffin BA, Caslake MJ, Yip B, et al. Rapid isolation of low density lipoprotein (LDL) subfractions from plasma by density gradient ultracentrifugation. Atherosclerosis . 1990;83:59-67.

Betteridge DJ. Effects of pioglitazone on lipid and lipoprotein metabolism. Diabetes Obes Metab. 2007;9:640-647.

Superko HR, Krauss RM. Differential effects of nicotinic acid in subjects with different LDL subclass patterns. Atherosclerosis . 1992;95:69-76.

Staels B, Dallongeville J, Auwerx J, et al. Mechanism of action of fibrates on lipid and lipoprotein metabolism. Circulation . 1998;98:2088-2093.

Sniderman AD. Differential response of cholesterol and particle measures of atherogenic lipoproteins to LDL-lowering therapy: Implications for clinical practice. J Clin Lipidol. 2008;2:36-42.

Brunzell JD, Davidson M, Furberg CD, et al. Lipoprotein management in patients with cardiometabolic risk: Consensus statement from the American Diabetes Association and the American College of Cardiology Foundation. Diabetes Care. 2008;31:811-822.

Marzullo P, Mariani G. From Basic Cardiac Imaging to Image Fusion. Core Competencies Versus Technological Progress: Springer. 2013.