People with low levels of LDL cholesterol are more likely to have
Parkinson's disease than people with high LDL levels, according to
University of North Carolina at Chapel Hill researchers.
LDL stands for low-density lipoprotein cholesterol; low levels of
LDL cholesterol are considered an indicator of good cardiovascular
health. Earlier studies have found intriguing correlations between
Parkinson's disease, heart attacks, stroke and smoking.

"People with Parkinson's disease have a lower occurrence of heart
attack and stroke than people who do not have the disease," said Dr.
Xuemei Huang, medical director of the Movement Disorder Clinic at
UNC Hospitals and an assistant professor of neurology in the UNC
School of Medicine. "Parkinson's patients are also more likely to
carry the gene APOE-2, which is linked with lower LDL cholesterol."
And for more than a decade, researchers have known that smoking,
which increases a person's risk for cardiovascular disease, is also
associated with a decreased risk of Parkinson's disease.

These findings led Huang to examine whether higher LDL cholesterol
might be associated with a decreased occurrence for Parkinson's
disease, and vice versa. "If my hypothesis was correct," she
said, "lower LDL-C, something that is linked to healthy hearts,
would be associated with a higher occurrence of Parkinson's." The
results of Huang's study, published online Dec. 18 by the journal
Movement Disorders, confirmed her hypothesis. "We found that lower
LDL concentrations were indeed associated with a higher occurrence
of Parkinson's disease," Huang said. Participants with lower LDL
levels (less than 114 milligrams per deciliter) had a 3.5-fold
higher occurrence of Parkinson's than the participants with higher
LDL levels (more than 138 milligrams per deciliter).

Huang cautioned that people should not change their eating habits,
nor their use of statins and other cholesterol-lowering drugs,
because of the results. The study was based on relatively small
numbers of cases and controls, and the results are too preliminary,
she said. Further large prospective studies are needed, Huang added.

"Parkinson's is a disease full of paradoxes," Huang said. "We've
known for years that smoking reduces the risk of developing
Parkinson's. More than 40 studies have documented that fact. But we
don't advise people to smoke because of the other more serious
health risks," she said.

Huang and her colleagues recruited 124 Parkinson's patients who were
treated at the UNC Movement Disorder Clinic between July 2002 and
November 2004 to take part in the study. Another 112 people, all
spouses of patients treated in the clinic, were recruited as the
control group. Fasting cholesterol profiles were obtained from each
participant. The researchers also recorded information on each
participant's gender, age, smoking habits and use of cholesterol-
lowering drugs.

Huang notes that the study also found participants with Parkinson's
were much less likely to take cholesterol-lowering drugs than
participants in the control group. This, combined with the findings
about LDL cholesterol, suggests two questions for additional study,
Huang said.

"One is whether lower cholesterol predates the onset of Parkinson's.
Number two, what is the role of statins in that? In other words,
does taking cholesterol-lowering drugs somehow protect against
Parkinson's? We need to address these questions," she said.

Dec 19, 2006 (YubaNet.com) -