In 2006, University of North Carolina at Chapel Hill researchers published a study that found people with low levels of LDL cholesterol are more likely to have Parkinson's disease than people with high LDL levels.
But that study could not answer the question of whether low LDL (low-density lipoprotein) levels were present in study participants before they were diagnosed with Parkinson's, or if they developed low LDL levels after being diagnosed.
Now a follow-up study led by UNC researchers in collaboration with colleagues in Virginia, Hawaii and Japan has found that low LDL levels were present in a group of men of Japanese ancestry long before these men were diagnosed with Parkinson's.
“This finding gives us one more piece in the puzzle about the role of cholesterol in Parkinson's disease,” said Dr. Xuemei Huang, the study's principal investigator. Huang is also medical director of the Movement Disorder Clinic at UNC Hospitals and an assistant professor of neurology in the UNC School of Medicine.
“What makes these results especially useful is the fact that most of the men in this study were not taking cholesterol-lowering drugs such as statins,” Huang said. “This suggests that the association between low LDL levels and Parkinson's exists independently from statin use, which helps answer another important question raised by our earlier study.”
The new study was published online this week by the journal Movement Disorders. Huang is the lead author. Her co-authors include Drs. G. Webster Ross and Helen Petrovitch, who are both with the Pacific Health Research Institute, the Veterans Affairs Pacific Islands Health Care System and the University of Hawaii; Dr. Robert D. Abbott of the University of Virginia and Shiga University in Japan; and Dr. Richard B. Mailman, a professor of psychiatry and pharmacology at the UNC School of Medicine.
Low levels of LDL cholesterol are clearly associated with good cardiovascular health. Huang's research adds to a growing literature indicating that people with low LDL may be at greater risk for developing Parkinson's.