Navigation Links
Low-Density Cholesterol Subfractions: Not all LDL-C Particles are Created Equal


Kerri Penno
Contributing Editor

Medical conventions are challenged every day. Already in the new year, the effectiveness of cold medicine and the gold standard in breast cancer treatment have been challenged. Standards in cholesterol testing are the latest casualty of medical innovation.

For years, cholesterol has been measured by a simple panel of high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C); good and bad cholesterol. In the past couple of decades, the National Cholesterol Education Program (NCEP) recommendations have evolved from the total cholesterol test to a fasting lipoprotein profilecomprised of total cholesterol, HDL-C, LDL-C and triglycerides.

These guidelines have operated under the assumption that high levels of LDL-C are essentially harmful; LDL-C has been associated with coronary heart disease (CHD), coronary artery disease (CAD), metabolic syndrome and atherosclerosis. However, studies on cholesterol testing effectiveness have long shown that the guidelines may not be universally effective at identifying a patients risk of cardiac events. In 1988, a study on cholesterol lipids and CAD noted that 75 percent of patients who suffer myocardial infarctions have normal levels of HDL-C and LDL-C (Castelli, Can J Cardiol 1988 4A:5A). These insufficiencies have led to the revision of the guidelines and additional studies to measure risk factors.

The NCEP recently released The Third Report of the Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III, or ATP III), reiterating and expanding on the aforementioned guidelines. ATP III identified LDL-C as the primary target of cholesterol-lowering therapy.

Recent studies, however, show that not all LDL-C particles are created equal. Two patients with similar LDL-C levels may, in fact, have a different makeup of LDL-C particles, rendering one more at risk for conditions such as CHD. The concentrations and sizes of the particles (LDL-C, small LDL, large HDL and large very-low-density lipoproteins) are better indicators of risk than the traditional lipid panel (Kraus et al, N Engl J Med 2002; 347:1483-92).

While a standard LDL-C panel may place a patient in the at-risk range for CAD, the breakdown of LDL subfractions may show that the patient is in fact, not at risk preventing overtreatment. In other cases, for patients that fall outside the traditional risk range, or near the border, an LDL particle breakdown may show that they in fact are at risk of CAD, due to an unhealthy distribution of particles. Accordingly, a number of tests have been developed that focus on lipid particle size and density.

The Lipoprint (Quantimetrix) was designed to do just that. The test uses a gel electrophoresis method to examine lipoprotein subfractions, including 12 cholesterol parameters. The Lipoprint identifies small, dense atherogenic particles that indicate a higher risk of metabolic syndrome and coronary events. Each patient receives a color-coded graphical representation of their particle breakdown and subsequent risk. The NMR LipoProfile (LipoScience, Inc.) also measures LDL particle size and distribution, by nuclear magnetic resonance spectroscopy blood test. The LipoProfile identifies the average size of LDL particles (in units of nanomoles of particles per liter), linking a greater distribution of small particles with the greatest risk for developing CHD and Type 2 Diabetes Mellitus. Patients with a high distribution of large LDL particles are at a lesser, but still significant risk for CHD. The VAP (Atherotech) also measures LDL particle size and density, in addition to hereditary risk factor and remnant lipoprotein, giving a more accurate depiction of the patients risk for CAD, CHD and metabolic syndrome.

Other analyses physically se parate and break down lipoproteins. The SPIFE Lipoprotein analyzer (Helena Laboratories) offers lipoprotein phenotypingseparating lipoproteins into alpha, pre-beta and beta lipoproteins, as well as chylomicrons.

Beyond identifying risk, a patients lipoprotein distribution also can serve as a better indicator of treatment efficacy than the traditional lipid panel. Treatment efficiency varies with subfraction makeup as well. After implementing lifestyle and diet changes, the NCEP recommends the following drug treatments to lower LDL-C and raise HDL-C; HMG CoA reductase inhibitors (statins), bile acid sequestrants, nicotinic acids and Fibric acids. All of these treatments also lower triglyceride levels, with the exception of bile acid sequestrants. New evidence illustrates that small LDL particle concentration can be substantially reduced by statin combination therapy. Obtaining a clear breakdown of lipoprotein particle size and concentration can offer better, more individualized treatment methods than drugs designed to lower overall cholesterol levels.

In fact, if treatment with an LDL-lowering drug (statins are the primary drug of choice) is unsuccessful, the NCEP recommends combining treatments, and referring the patient to a lipid specialist if this tactic proves unsuccessful. As cholesterol testing evolves, new guidelines, studies and common practice are moving toward more specific, specialized testing that identifies each patients true risk, and offers more appropriate, effective, individualized treatment solutions.
'"/>




Related medicine technology :

1. Lexicon Develops Antibodies That Lower Triglycerides and Cholesterol as Potential New Therapy for Heart Disease
2. DiObex Presents Phase 2a Data of DIO-902 Demonstrating Trends of Improved Glycemic Control and Significant Reductions of LDL-Cholesterol and C-Reactive Protein
3. KineMed Presents Data Measuring Changes in Reverse Cholesterol Transport for the First Time
4. CSL Therapy That Mimics “Good” Cholesterol May Reduce Plaque Volume in Coronary Arteries
5. CSL Therapy That Mimics Good Cholesterol May Reduce Plaque Volume in Coronary Arteries
6. Cholesterol Drug Fails to Slow Progression of Coronary Disease, Cleveland Clinic Study Reports
7. Study Presented at ACC Shows Treatment With ISIS 301012 Added to Statins for Only 5 Weeks Results in 75% of Patients Achieving LDL-C Levels Less Than 100 mg/dL and 50% of Patients Achieving LDL-C Levels of Less Than 70 mg/dL
8. In New Study, Duloxetine Was Equally Effective, Regardless of Switch Method, in Reducing Painful Symptoms in Ssri Non- or Partial-responders with Depression

Post Your Comments:
*Name:
*Comment:
*Email:
(Date:10/2/2017)... 2017  Eli Lilly and Company (NYSE: ... third quarter of 2017 on Tuesday, October 24, 2017. ... day with the investment community and media to further ... call will begin at 9 a.m. Eastern time. Investors, ... webcast of the conference call through a link that ...
(Date:10/2/2017)... Halo Labs announces the European launch of their new low volume, ... 2017 in Cambridge, U.K on October 4th. ... samples with unprecedented speed and sensitivity while using far less sample ... ... system ...
(Date:9/28/2017)... Hill-Rom Holdings, Inc. (NYSE: HRC), will host its fiscal ... Friday, November 3, 2017, beginning at 7:00 a.m. (CDT) ... a.m. (CDT) / 9:30 a.m. (EDT). In ... guidance for 2018, Hill-Rom executives will also highlight the ... long-range financial outlook through 2020. ...
Breaking Medicine Technology:
(Date:10/13/2017)... , ... October 13, 2017 , ... Lori R. Somekh, ... member of ElderCounsel, a national organization of elder law and special needs planning attorneys. ... and rules. It also provides a forum to network with elder law attorneys nationwide,” ...
(Date:10/13/2017)... New York, NY (PRWEB) , ... October 13, 2017 , ... ... most influential people in business to advocate for action towards gender equality at their ... 18,000 views from around the globe, and reached a social audience of over 3 ...
(Date:10/13/2017)... ... October 13, 2017 , ... Coveros, a ... has been awarded a contract by the Center for Medicare and Medicaid Services ... accelerate the enterprise use of Agile methodologies in a consistent and high value ...
(Date:10/12/2017)... San Francisco, CA (PRWEB) , ... October 12, ... ... and Dr. Cheng, are now treating sleep apnea using cutting-edge Oventus ... sleep apnea, a serious sleep disorder characterized by frequent cessation in breathing. Oral ...
(Date:10/12/2017)... ... October 12, 2017 , ... The American College of Medical ... Friedman, PhD, FACMI, during the Opening Session of AMIA’s Annual Symposium in Washington, D.C. ... honor of Morris F. Collen, a pioneer in the field of medical informatics, this ...
Breaking Medicine News(10 mins):