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 Second cause of hidden hearing loss identified
20.02.2017 | Michigan Medicine - University of Michigan

nachricht Prospect for more effective treatment of nerve pain
20.02.2017 | Universität Zürich

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Switched-on DNA

20.02.2017 | Materials Sciences

Second cause of hidden hearing loss identified

20.02.2017 | Health and Medicine

Prospect for more effective treatment of nerve pain

20.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>