Statins May Speed Development of Parkinson's Disease

Some studies indicate that taking statins, which are commonly used to lower cholesterol, may provide protection against Parkinson’s disease. There has been conflicting evidence regarding the use of these drugs and the risk of Parkinson’s disease.

The results from a new study published by Movement Disorders suggest that statin use may speed the development of Parkinson’s disease among patients who are at risk.

"One of the reasons that may have explained these prior inconsistent results is that higher cholesterol, the main indication to use statins, has been related to lower occurrence of Parkinson's disease," said researcher Xuemei Huang, MD, PhD. "This made it hard to know if the statin protective effect was due to the drug or preexisting cholesterol status."

The authors also cited different types of statins as contributing factors to the conflicting results. While water-soluble statins cannot cross the blood-brain barrier, fat-soluble statins do have that ability. Since patients can be treated with either form of statin, determining how the drugs affect Parkinson’s disease risk can be difficult, according to the study.

Included in the study were data from insurance claims for more than 50 million patients. The authors identified nearly 22,000 patients with Parkinson’s disease, of whom 2322 were newly-diagnosed. The patients were matched with control participants.

After analyzing the data, the investigators discovered that previous statin use was linked to a higher risk of developing Parkinson’s disease. They found that the link was the most substantial during the start of statin use, according to the study.

"Statin use was associated with higher, not lower, Parkinson's disease risk, and the association was more noticeable for lipophilic statins, an observation inconsistent with the current hypothesis that these statins protect nerve cells," Dr Huang said. "In addition, this association was most robust for use of statins less than 2.5 years, suggesting that statins may facilitate the onset of Parkinson's disease."

The investigators concluded statin use was associated with an increased risk of Parkinson’s disease for those already at risk. Additionally, they accounted for hyperlipidemia in the study.

"Our analysis also showed that a diagnosis of hyperlipidemia, a marker of high cholesterol, was associated with lower Parkinson's disease prevalence, consistent with prior research,” said researcher Guodong Liu, PhD. “We made sure to account for this factor in our analysis."

The authors reported the results of another study that found patients had a higher risk of Parkinson’s disease after they stopped taking statins, which investigators interpreted as statins providing a protective effect.

"Our new data suggests a different explanation," Dr Huang said. "Use of statins may lead to new Parkinson's disease-related symptoms, thus causing patients to stop using statins."

The authors caution that additional research is needed to establish the link and note that patients who are taking statins should continue their therapy.

"We are not saying that statins cause Parkinson's disease, but rather that our study suggests that statins should not be used based on the idea that they will protect against Parkinson's," Dr Huang said. "People have individual levels of risk for heart problems or Parkinson's disease. If your mom has Parkinson's disease and your grandmother has Parkinson's disease, and you don't have a family history of heart attacks or strokes, then you might want to ask your physician more questions to understand the reasons and risks of taking statins."