LDL-P

Lipoproteins are particles that transport fats throughout the body. These particles are essential and carry a combination of proteins, vitamins, cholesterol, triglyceride, and phospholipid molecules.

The composition of a lipoprotein particle changes as it circulates in the blood. Some molecules are removed and others are added, resulting in lipoprotein particles with variable amounts of cholesterol. Low-density lipoprotein particles (LDL-P) are bi-products of fat transport that remain in circulation for an extended time. While in circulation, LDL-P can penetrate the artery wall and get stuck, forming a fatty plaque. These plaques can build over time and lead to blockages, resulting in heart attacks and strokes. The likelihood of an LDL-P getting trapped in the artery wall increases when more LDL-P are in the blood. Traditional lipid testing measures the amount of LDL cholesterol (LDL-C) present in the blood, but it does not evaluate the number of LDL particles (LDL-P). LDL-P is often used to get a more accurate measure of LDL due to the variability of cholesterol content within a given LDL. Studies have shown that LDL-P more accurately predicts risk of cardiovascular disease than LDL-C. Researchers think that increased LDL-P could be one of the reasons that some people have heart attacks even though their total cholesterol and LDL cholesterol levels are not particularly high.

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- LDL-P is the direct measure of low density lipoprotein particles - the causal link between high levels of LDL-P and development of cardiovascular disease (CVD) is well established.

- Studies have demonstrated per-particle cholesterol amount varies in patients with type II diabetes, statin-treated patients, and those with cardiometabolic risk factors (CMR) listed below: [1, 2 , 3]

                    Age: men ≥45 yrs, women ≥ 55 yrs) [4]

                    Elevated BP: (≥130/≥85 mmHg; on antihypertensive medication) [5]

                    Abdominal obesity/waist circumference: male ≥ 40” (Asian ≥ 35”), female ≥ 35” (Asian ≥ 31”) [5]

                    Elevated triglycerides: (≥150 mg/dL), low HDL (men < 40 mg/dL, women < 50 mg/dL), increased numbers of small dense                     LDL particles, [2, 5], on drug treatment for elevated triglycerides or HDL-C

                    Elevated fasting blood glucose: (≥ 100 mg/dL), [5] on drug treatment for elevated glucose

                    Insulin resistance: (IR) [2]

- Many expert panels recommend use of LDL-P values to optimize treatment decisions in these at-risk patients. [2, 6]

- NMR LipoProfile Test is FDA cleared for use in conjunction with other lipid measurements and clinical evaluation to aid in the management of lipoprotein disorders associated with CVD. [7]

References:

1. Toth PP, Grabner M, Punekar RS et al. Cardiovascular risk in patients achieving lowdensity lipoprotein cholesterol and particle targets. Atherosclerosis. 2014 (235)585-591. [1]

2. 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 April; (31)4:811-82. [2]

3. Sniderman AD, Williams K, Contois JH et al. A meta-analysis of low-density lipoprotein cholesterol, non-high-density lipoprotein cholesterol, and apolipoprotein B as markers of cardiovascular risk. Circ Cardiovasc Qual Outcomes. 2011;4:337-345. [3]

4. National Heart, Lung, and Blood Institute. Executive Summary. The Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III), National Institutes of Health. May 2001. NIH publication 01-3670; 1-28. [4]

5. Grundy SM, Cleeman JI, Daniels SR et al. Diagnosis and management of the metabolic syndrome: An American Heart Association/ National Heart, Lung, and Blood Institute scientific statement: Executive Summary, Circulation. 2005; 112 e285-e290. [5]

6. Garber AJ, Abrahamson MJ, Barzilay JI, Blonde L, Bloomgarden ZT, Bush MA, Dagogo-Jack S, DeFronzo RA, Einhorn D, Fonseca VA, Garber JR, Garvey WT, Grunberger G, Handelsman Y, Henry RR, Hirsch IB, Jellinger PS, McGill JB, Mechanick JI, Rosenblit PD and Umpierrez GE. Consensus Statement by the American Association of Clinical Endocrinologists and American College of Endocrinology on the Comprehensive Type 2 Diabetes Management Algorithm - 2016 Executive Summary. Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists. 2016;22:84-113. [6]

7. NMR LipoProfile® [package insert]. Raleigh, NC: Laboratory Corporation of America; 2015. [7]