Use of statins may not be associated with reduced risk of Parkinson's disease, a new study has found.
The study led by researchers at Penn State College of Medicine and National Institute of Environmental Health Sciences casts doubts on reports suggesting that the cholesterol-lowering medications may protect against the neurodegenerative brain disorder.
Xuemei Huang, professor of neurology and vice chair for research, Penn State College of Medicine, previously reported an association between high blood cholesterol levels and lower incidence of Parkinson's disease (PD).
A low incidence of heart attack and stroke in PD patients in movement disorder clinics, despite their usually advanced age, motivated these studies. Other studies also reported similar findings.
However, evidence has been somewhat inconsistent. The use of statins has also been associated with a lower incidence of PD in several recent epidemiology studies, leading some researchers to hypothesise that medications, which lower levels of LDL - bad cholesterol - may protect against PD.
Those studies, however, failed to account for cholesterol levels prior to the widespread use of statins in the US population, Huang said.
The researchers looked at blood cholesterol levels, medications and PD status in participants in the ongoing, long-term Atherosclerosis Risk in Communities study.
Cholesterol readings were taken at three-year intervals over the course of a decade from 1987, before widespread statin use began.
"We confirmed our previous finding that high total cholesterol and LDL cholesterol were associated with a lower risk of PD," Huang said.
"Moreover, statin use over the course of the study did not protect against PD, and in fact appeared to increase PD risk in the long term.
"Although the analysis on statin use and PD was based on a fairly small number of PD cases, this preliminary data argues against the hypothesis that statins protect against PD," Huang said.
"One possibility is that statin use can be a marker of people who have high cholesterol which itself may be associated with lower PD risk," Huang said.
"This could explain why some studies have found an association between use of these medications and low incidence of PD. Most importantly, this purported benefit may not be seen over time," Huang said.
The research was published in the journal Movement Disorders.
