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 The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung

nachricht A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg

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: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Tracking movement of immune cells identifies key first steps in inflammatory arthritis

23.01.2017 | Health and Medicine

Electrocatalysis can advance green transition

23.01.2017 | Physics and Astronomy

New technology for mass-production of complex molded composite components

23.01.2017 | Process Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>