Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Some HDL, or 'good' cholesterol, may not protect against heart disease

08.05.2012
A new study by Harvard School of Public Health (HSPH) researchers has found that a subclass of high-density lipoprotein (HDL) cholesterol, the so-called "good" cholesterol, may not protect against coronary heart disease (CHD) and in fact may be harmful.
This is the first study to show that a small protein, apolipoprotein C-III (apoC-III), that sometimes resides on the surface of HDL cholesterol may increase the risk of heart disease and that HDL cholesterol without this protein may be especially heart protective.

The study was published online in the Journal of the American Heart Association.
"This finding, if confirmed in ongoing studies, could lead to better evaluation of risk of heart disease in individuals and to more precise targeting of treatments to raise the protective HDL or lower the unfavorable HDL with apoC-III," said Frank Sacks, professor of cardiovascular disease prevention at HSPH and senior author of the study.

A high level of HDL cholesterol is strongly predictive of a low incidence of coronary heart disease (CHD). But trials of drugs that increase HDL cholesterol have not consistently shown decreases in CHD, leading to the hypothesis that HDL cholesterol may contain both protective and non-protective components.
ApoC-III, a proinflammatory protein, resides on the surface of some lipoproteins—both HDL and low-density lipoproteins, or LDL ("bad") cholesterol. The researchers, led by Sacks and Majken Jensen, research associate in the Department of Nutrition at HSPH, examined whether the existence or absence of apoC-III on HDL cholesterol affected the "good" cholesterol's heart-protective qualities, and whether its existence could differentiate HDL cholesterol into two subclasses—those which protect against the risk of future heart disease and those which do not.

Blood samples collected in 1989 and 1990 from 32,826 women in the Brigham and Women's Hospital-based Nurses' Health Study were examined, along with blood samples collected from 1993 to 1995 from 18,225 men in the Health Professionals Follow-up Study. During 10 to 14 years of follow-up, 634 cases of coronary heart disease were documented and matched with controls for age, smoking, and date of blood drawing.

The researchers compared plasma concentrations of total HDL, HDL that has apoC-III, and HDL without apoC-III as predictors of the risk of CHD.

After adjusting for age, smoking status and other dietary and lifestyle cardiovascular risk factors, the researchers found that two different subclasses of HDL have opposite associations with the risk of CHD in apparently healthy men and women. The major HDL type, which lacks apoC-III, had the expected heart-protective association with CHD. But the small fraction (13%) of HDL cholesterol that has apoC-III present on its surface was paradoxically associated with a higher, not lower, risk of future CHD. Those men and women who had HDL apoC-III in the highest 20% of the population had a 60% increased risk of CHD.

The results suggest that measuring HDL apoC-III and HDL without apoC-III rather than the simpler measure of total HDL may be a better gauge of heart disease risk (or of HDL's protective capacity). "Reduction in HDL-apoC-III by diet or drug treatments may become an indicator of efficacy," said Jensen.

The study was supported by The National Institutes of Health and the Villum Kann Rasmussen Foundation (Denmark).

"Apolipoprotein C-III as a Potential Modulator of the Association Between HDL-Cholesterol and Incident Coronary Heart Disease," Majken K. Jensen, Eric B. Rimm, Jeremy D. Furtado, Frank M. Sacks, Journal of the American Heart Association, April 2012.

Harvard School of Public Health is dedicated to advancing the public's health through learning, discovery and communication. More than 400 faculty members are engaged in teaching and training the 1,000-plus student body in a broad spectrum of disciplines crucial to the health and well being of individuals and populations around the world. Programs and projects range from the molecular biology of AIDS vaccines to the epidemiology of cancer; from risk analysis to violence prevention; from maternal and children's health to quality of care measurement; from health care management to international health and human rights. For more information on the school visit www.hsph.harvard.edu.

Todd Datz | EurekAlert!
Further information:
http://www.hsph.harvard.edu

More articles from Studies and Analyses:

nachricht Amputees can learn to control a robotic arm with their minds
28.11.2017 | University of Chicago Medical Center

nachricht The importance of biodiversity in forests could increase due to climate change
17.11.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>