Researchers at Korea University Ansan Hospital have found that the low levels of high-density lipoprotein (HDL) cholesterol and its wide fluctuations can increase the risk of Parkinson's disease by up to 60 percent.

The team, led by Professors Park Joo-hyun and Kim Do-hoon at the hospital, conducted a retrospective cohort study using the National Health Insurance data of 380,404 people aged 65 and over without Parkinson's disease who received three or more health checkups from 2008 to 2013.

As a result of investigating newly developed Parkinson's disease during the follow-up period, which continued through the end of 2017, the team confirmed that the group with the lowest HDL cholesterol level at the initial stage of cohort registration had a 21 percent increased risk of suffering from Parkinson's disease.

It also found that the risk of Parkinson's disease increased by up to 60 percent when the HDL cholesterol variability between screenings was large. People who had underlying diseases of obesity or chronic kidney had a higher risk than those who did not.

"High plasma HDL cholesterol levels have been widely known as important protective factors against cardiovascular disease," the team said. "In addition to the well-known protective effect from atherosclerosis, HDL cholesterol levels can directly contribute to maintaining the proper function of many organs and tissues through the activation of various antioxidant pathways and alleviating inflammatory responses."

Through this study, the researchers revealed that maintaining high plasma HDL cholesterol levels may help decrease the risk of developing neurodegenerative diseases, such as Parkinson's disease.

The results of this study were selected as a representative paper in the March 2021 issue of Neurology.