The use of statins may not be associated with lowering risk for Parkinson's disease ( PD ), according to a new study led by researchers at Penn State College of Medicine and National Institute of Environmental Health Sciences.
The findings cast doubts on reports suggesting that the cholesterol-lowering medications may protect against this neurodegenerative brain disorder.
Researchers at Penn State College of Medicine previously reported an association between high blood cholesterol levels and lower incidence of Parkinson’s disease.
A low incidence of myocardial infarction and stroke in Parkinson’s desease 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 Parkinson disease in several recent epidemiology studies, leading some researchers to hypothesize that these medications, which lower levels of LDL cholesterol may protect against Parkinson’s disease. Those studies, however, failed to account for cholesterol levels prior to the widespread use of statins in the U.S. population.
The researchers looked at blood cholesterol levels, medications and Parkinson 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 to 1989, before widespread statin use began.
Researchers confirmed the previous finding that high total cholesterol and LDL cholesterol were associated with a lower risk of Parkinson’s disease. Moreover, statin use over the course of the study did not protect against Parkinson’s disease, and in fact appeared to increase risk of Parkinson in the long term.
Although the analysis on statin use and Parkinson disease was based on a fairly small number of PD cases, this preliminary data argues against the hypothesis that statins protect against PD.
The researchers reported their finding in the journal Movement Disorders.
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. 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.
Future research should focus on if and why cholesterol may protect against Parkinson’s disease. Although blood cholesterol is not indicative of cholesterol in the brain, there is increasing evidence that Parkinson’s disease may begin outside the brain. Statin-induced decreases in blood cholesterol levels may have unknown consequences in these peripheral areas.
A compound called coenzyme Q10 that is produced alongside cholesterol may also be an area of future Parkinson research. Statins reduce coenzyme Q10, which helps produce energy for cells and is hypothesized to have protective qualities in nerve cells.
An estimated 43 million Americans currently take statins or are eligible for statin therapy. Recent updates to American Heart Association guidelines are expected to increase that number to 56 million or more. The new guidelines recommend statin use for some patients without high cholesterol but who have other risk factors for heart disease and stroke. ( Xagena )
Source: Penn State College of Medicine, 2015