In order to bring you the best possible user experience, this site uses Javascript. If you are seeing this message, it is likely that the Javascript option in your browser is disabled. For optimal viewing of this site, please ensure that Javascript is enabled for your browser.
Did you know that your browser is out of date? To get the best experience using our website we recommend that you upgrade to a newer version. Learn more.
ESC Congress 2020 Register

Too much of a good thing? Very high levels of “good” cholesterol may be harmful

Lipids
Nutrition, Malnutrition and Heart Disease
Risk Factors and Prevention


Munich, Germany – 25 Aug 2018: Very high levels of high-density lipoprotein (HDL or “good”) cholesterol may be associated with an increased risk of heart attack and death, according to research presented today at ESC Congress 2018. (1)

Study author Dr Marc Allard-Ratick, of Emory University School of Medicine, Atlanta, US, said: “It may be time to change the way we view HDL cholesterol. Traditionally, physicians have told their patients that the higher your ‘good’ cholesterol, the better. However, the results from this study and others suggest that this may no longer be the case.”

HDL cholesterol has been considered “good” because the HDL molecule is involved in the transport of cholesterol from the blood and blood vessel walls to the liver and ultimately out of the body, thereby reducing the risk of clogged arteries and atherosclerosis. People with low HDL cholesterol have a greater risk of atherosclerosis and cardiovascular disease. But the protective effect of very high HDL cholesterol has been unclear.

This study, conducted as part of the Emory Cardiovascular Biobank, investigated the relationship between HDL cholesterol levels and the risk of heart attack and death in 5,965 individuals, most of whom had heart disease. The average age of participants was 63 years and 35% were female.

Participants were divided into five groups according to their HDL cholesterol level: less than 30 mg/dl (0.78 mmol/L), 31–40 mg/dl (0.8–1 mmol/L); 41–50 mg/dl (1.1–1.3 mmol/L); 51–60 mg/dl (1.3–1.5 mmol/L); and greater than 60 mg/dl (1.5 mmol/L).

During a median follow-up of four years, 769 (13%) participants had a heart attack or died from a cardiovascular cause. Participants with HDL cholesterol 41–60 mg/dl (1.1–1.5 mmol/L) had the lowest risk of heart attack or cardiovascular death. Risk was increased both in participants with low levels (less than 41 mg/dl) and very high levels (greater than 60 mg/dl) of HDL cholesterol, which produced a U-shaped curve when plotted graphically. 

Participants with HDL cholesterol levels greater than 60 mg/dl (1.5 mmol/L) had a nearly 50% increased risk of dying from a cardiovascular cause or having a heart attack compared to those with HDL cholesterol levels 41–60 mg/dl (1.1–1.5 mmol/L).

The associations were consistent even after controlling for other risk factors for heart disease such as diabetes, smoking, and low-density lipoprotein (LDL or “bad”) cholesterol, as well as other factors linked with high HDL cholesterol such as alcohol intake, race, and sex.

The results support findings from several large population-based studies, including a recent publication which found increased cardiovascular and all-cause death when HDL cholesterol reached extremely high levels. (2) Dr Allard-Ratick said: “Our results are important because they contribute to a steadily growing body of evidence that very high HDL cholesterol levels may not be protective, and because unlike much of the other data available at this time, this study was conducted primarily in patients with established heart disease.”

He noted that more research is needed to elucidate the mechanisms of this paradoxical association. “While the answer remains unknown, one possible explanation is that extremely elevated HDL cholesterol may represent ‘dysfunctional HDL’ which may promote rather than protect against cardiovascular disease,” he said.

Dr Allard-Ratick concluded: “One thing is certain: the mantra of HDL cholesterol as the ‘good’ cholesterol may no longer be the case for everyone.”

 

ENDS

Notes to editor

SOURCES OF FUNDING: None.

DISCLOSURES: None. 

References 

(1) The abstract “Elevated HDL-C is associated with adverse cardiovascular outcomes” will be presented during:

(2) Madsen CM, Varbo A, Nordestgaard BG. Extreme high high-density lipoprotein cholesterol is paradoxically associated with high mortality in men and women: two prospective cohort studies. Eur Heart J. 2017;38:2478–2486

ESC Press Office
For press enquiries, independent comment, please contact the ESC Press Office at press@escardio.org

To access congress scientific resources visit ESC Congress 365.


About the European Society of Cardiology

The European Society of Cardiology brings together health care professionals from more than 150 countries, working to advance cardiovascular medicine and help people lead longer, healthier lives.

About ESC Congress 2018

ESC Congress is the world’s largest and most influential cardiovascular event contributing to global awareness of the latest clinical trials and breakthrough discoveries. ESC Congress 2018 takes place 25 to 29 August at the Messe München in Munich, Germany. Explore the scientific programme.

 

This press release accompanies both a presentation and an ESC press conference at the ESC Congress 2018. Edited by the ESC from material supplied by the investigators themselves, this press release does not necessarily reflect the opinion of the European Society of Cardiology. The content of the press release has been approved by the presenter.