Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Johns Hopkins heart researchers develop formula to better calculate 'bad' cholesterol in patients

18.11.2013
Findings follow previous study showing that commonly used equation underestimates heart disease danger for many at high risk

Johns Hopkins researchers have developed a more accurate way to calculate low-density lipoprotein (LDL) cholesterol, the so-called "bad" form of blood fat that can lead to hardening of the arteries and increase the risk of heart attack and stroke.

If confirmed and adopted by medical laboratories that routinely calculate blood cholesterol for patients, the researchers say their formula would give patients and their doctors a much more accurate assessment of LDL cholesterol.

"The standard formula that has been used for decades to calculate LDL cholesterol often underestimates LDL where accuracy matters most — in the range considered desirable for patients at high risk for heart attack and stroke," says Seth S. Martin, M.D., a cardiology fellow at the Johns Hopkins Ciccarone Center for the Prevention of Heart Disease. Martin is first author of the study detailed in a Nov. 19, 2013 article in the Journal of the American Medical Association.

Many studies have shown that higher levels of LDL cholesterol signal greater risk of plaque accumulating in heart arteries. Since 1972, a formula called the Friedewald equation has been used to gauge LDL cholesterol. It is an estimate rather than a direct measurement. However, physicians use the number to assess their patients' risk and determine the best course of treatment.

The Friedewald equation estimates LDL cholesterol with the following formula: total cholesterol minus HDL cholesterol minus triglycerides divided by five. The result is expressed in milligrams per deciliter. That equation, the researchers say, applies a one-size-fits-all factor of five to everyone; a more accurate formula would take specific details about a person's cholesterol and triglyceride levels into account.

Using a database of blood lipid samples from more than 1.3 million Americans that were directly measured with a traditional and widely accepted technique known as ultracentrifugation, the researchers developed an entirely different system and created a chart that uses 180 different factors to more accurately calculate LDL cholesterol and individualize the assessment for patients.

"We believe that this new system would provide a more accurate basis for decisions about treatment to prevent heart attack and stroke," says Martin.

Results of the new study are built on research by the same authors from the Johns Hopkins University School of Medicine and published in the Journal of the American College of Cardiology. In that study, the researchers compared samples assessed using the Friedewald equation with a direct calculation of the LDL cholesterol.

They found that in nearly one out of four samples in the "desirable" range for people with a higher heart disease risk, the Friedewald equation was not accurate.

"As a result, many people — especially those with high triglyceride levels — may have a false sense of assurance that their LDL cholesterol is at an ideal level. Instead, they may need more aggressive treatment to reduce their heart disease risk," says Steven Jones, M.D., director of inpatient cardiology at The Johns Hopkins Hospital and a faculty member at the Ciccarone Center who is the senior author of the study.

The lipid profiles used for the study were from a laboratory in Birmingham, Ala., which provides a detailed analysis of samples sent in by doctors across the country. Except for the age of people on whom the samples were based (59 years on average) and the gender (52 percent of the samples were from women), the patients were not identifiable to the researchers. That database was almost 3,000 times larger than the sample used to devise the Friedewald equation 43 years ago.

Jones, who originated the idea to use the large laboratory database to assess the Friedewald equation, says the information was provided by the lab at no cost. The lab, Atherotech, did not provide any funding for the research or input on the calculations or study article. The database used in the study is registered on the website http://www.clinicaltrials.gov and will be an important resource for ongoing scientific investigation.

Jones and Martin are listed on a patent pending for the new system, which was filed by The Johns Hopkins University. Dr. Martin is supported by the Pollin Cardiovascular Prevention Fellowship, as well as the Marie-Josée and Henry R. Kravis endowed fellowship.

In addition to Martin and Jones, other researchers on the study were: Michael J. Blaha, Mohamed B. Elshazly, Peter O. Kwiterovich and Roger S. Blumenthal from the Johns Hopkins University School of Medicine, and Peter P. Toth from the University of Illinois College of Medicine at Peoria.

Johns Hopkins Medicine (JHM), headquartered in Baltimore, Maryland, is a $6.7 billion integrated global health enterprise and one of the leading academic health care systems in the United States. JHM unites physicians and scientists of the Johns Hopkins University School of Medicine with the organizations, health professionals and facilities of The Johns Hopkins Hospital and Health System. JHM's vision, "Together, we will deliver the promise of medicine," is supported by its mission to improve the health of the community and the world by setting the standard of excellence in medical education, research and clinical care. Diverse and inclusive, JHM educates medical students, scientists, health care professionals and the public; conducts biomedical research; and provides patient-centered medicine to prevent, diagnose and treat human illness. JHM operates six academic and community hospitals, four suburban health care and surgery centers, and more than 35 Johns Hopkins Community Physicians sites. The Johns Hopkins Hospital, opened in 1889, was ranked number one in the nation for 21 years in a row by U.S. News & World Report. For more information about Johns Hopkins Medicine, its research, education and clinical programs, and for the latest health, science and research news, visit http://www.hopkinsmedicine.org.

Media Contacts:

Ellen Beth Levitt, eblevitt@jhmi.edu, 410-955-5307 or 410-598-4711 (cell)

Helen Jones, hjones49@jhmi.edu, 410-502-9422

(Note: Dr. Martin and his co-authors will be at the American Heart Association Scientific Sessions in Dallas for in-person interviews).

Ellen Beth Levitt | EurekAlert!
Further information:
http://www.jhmi.edu
http://www.hopkinsmedicine.org

More articles from Health and Medicine:

nachricht GLUT5 fluorescent probe fingerprints cancer cells
20.04.2018 | Michigan Technological University

nachricht Scientists re-create brain neurons to study obesity and personalize treatment
20.04.2018 | Cedars-Sinai Medical Center

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Structured light and nanomaterials open new ways to tailor light at the nanoscale

23.04.2018 | Physics and Astronomy

On the shape of the 'petal' for the dissipation curve

23.04.2018 | Physics and Astronomy

Clean and Efficient – Fraunhofer ISE Presents Hydrogen Technologies at the HANNOVER MESSE 2018

23.04.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>