Individuals with both low and high HDL cholesterol had high risk of hospitalization with an infectious disease, a Danish study found

A new study has found a link between a higher risk of infectious diseases and high and low levels of “good cholesterol” alike, Medical News Today reports.

High-density lipoprotein (HDL) cholesterol, known as "good cholesterol," helps to "flush" the cholesterol out of the system by carrying it to the liver.

Recently studies have tried to understand actually how good is good cholesterol for health. 
Now Danish Researchers working at Copenhagen University Hospital and the University of Copenhagen — who were led by Prof. Børge Nordestgaard have noted that both high and low levels of HDL cholesterol may put our health in danger. Results show that high, as well as low, HDL cholesterol is strongly linked to a higher risk of hospitalization due to infectious diseases. 

The study’s results have been reported in the European Heart Journal.

The scientists analyzed the health data of 97,166 people who were enrolled in the Copenhagen General Population Study, as well as that of an additional 9,387 people who participated in the Copenhagen City Heart Study.

Numerous studies in animals and cells," says study co-author Christian Medom Madsen, "indicate that HDL is of importance for the function of the immune system and thereby the susceptibility to infectious disease, but this study is the first to examine if HDL is associated with the risk of infectious disease among individuals from the general population."

All the participants were assessed for HDL cholesterol levels at baseline, and they were followed-up for over 6 years.

It was found that 21 percent of the people who presented the lowest concentrations of HDL cholesterol — as well as 8 percent of those with the highest levels of this type of cholesterol — had an increased risk of developing infectious diseases such as gastroenteritis or pneumonia.

Surprisingly, we found that individuals with both low and high HDL cholesterol had high risk of hospitalization with an infectious disease. Perhaps more importantly, these same groups of individuals had high risk of dying from infectious disease.", prof. Børge Nordestgaard comments. 

Despite these results, the researchers caution that a clear, causal relationship cannot, for now, be established between high or low HDL cholesterol and predisposition to such diseases.