We may all be aware of the key role high cholesterol plays in causing heart attacks and strokes. Too much of the vital cell building material increases the risk, and high levels are caused by our genetics and lifestyles.
Doctors talk of so-called good (HDL) cholesterol and bad (LDL) cholesterol, and it is the bad cholesterol that concerns medics most.
But it’s not all been bad news. Researchers in Canada now believe that good cholesterol may be ‘even better cholesterol’ – as they get to grips with an exciting possibility that HDL may help in the fight against blood poisoning (sepsis) that causes 11 million deaths every year.
The scientists looked at data on more than 400,000 UK Biobank participants to learn more about sepsis, which is a life-threatening inflammatory immune response brought on by infection. Sepsis is a medical emergency and causes around one in five deaths globally.
Dr Liam Brunham, Assistant Professor of Medicine at the University of British Columbia and MD/PhD student and doctoral candidate Mark Trinder examined genetic data and cholesterol measures in over 3,000 participants who developed the illness.
“We could not have done this work without a resource like UK Biobank, because it contains both genetic information and detailed data about individual health.”Assistant Professor Brunham
The researchers explained that HDL levels fall quickly during sepsis, which may limit their ability to bind and clear toxins from the blood.
The genetic data provided by UK Biobank participants allowed the researchers to identify people with naturally high good (HDL) cholesterol levels. Information on prescription of antibiotics was also studied.
The researchers plan to test their work further. “It may not be possible to treat people before they get an infection, but if raising good cholesterol during the infection prevents sepsis or promotes its resolution that would be a major step forward.”Assistant Professor Brunham
The researchers published their findings in the American Heart Association’s Journal Arteriosclerosis, Thrombosis, and Vascular Biology.
“This is particularly promising area of research, because drugs already exist to increase good cholesterol” said Mr Trinder.
Previously, scientists have used drugs to increase good cholesterol in the hope of reducing heart attacks and strokes. “Good cholesterol is thought of as being protective of heart disease, but it may be that it is just a by-stander as it relates to heart disease,” he added.
But with evidence of a causal relationship between HDL and death from sepsis, it seems be there may a role for those drugs after all.
A comment in the Journal, indicated that previous observations had raised the possibility that HDL is an important regulator of the immune system and our body’s defence mechanisms against invading pathogens. It concluded: “Subjects with a high HDL-C polygenic risk score were significantly more likely to survive their infection…these observations provide strong evidence that HDL, quantified as HDL-C, is causally linked to host defence mechanism against infection.”