Study suggests statins associated with higher risk for Parkinson's disease in some patients

Researchers at the Penn State College of Medicine have published data that suggest statin use may accelerate the onset of symptoms of Parkinson’s disease in patients who are susceptible to the disease. The data is published in the journal Movement Disorders.

Statins have been the focus of studies to determine their protective effect against Parkinson’s, but research has been inconsistent.

“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 Xuemei Huang, MD, PhD, Professor of Neurology. “This made it hard to know if the statin protective effect was due to the drug or preexisting cholesterol status.”

Another reason for the inconsistency is that water-soluble statins cannot pass through to the brain, while lipophilic statins can. These differences can make interpretation of results difficult as they relate to Parkinson’s disease.

In this study, researchers analyzed a commercially-available database of insurance claims for more than 50 million people. Nearly 22,000 people with Parkinson’s disease were identified; the number was narrowed to 2,322 patients with newly diagnosed disease.

Each of these patients was paired with a control—another patient who did not have Parkinson’s disease according to the database. Investigators then determined which patients had been taking a statin and for how long prior to the onset of Parkinson’s symptoms.

Results showed that prior statin use was associated with higher risk of Parkinson’s disease—the risk was more noticeable during the start of drug use.

“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 two-and-a-half years, suggesting that statins may facilitate the onset of Parkinson’s disease.”

Guodong Liu, PhD, Assistant Professor of Public Health Sciences, indicated that the analysis also showed that a diagnosis of hyperlipidemia was associated with lower Parkinson’s disease prevalence, which is consistent with prior research. He added that the team made sure to account for this factor in the new analysis.

A recent research study reported that people who stopped using statins were more likely to be diagnosed with Parkinson’s disease. This was interpreted as evidence that statins protect against Parkinson’s disease.

“Our new data suggest 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.”

Dr. Huang stressed that more research needs to be completed. Those patients receiving statins should continue to take the medication their health care provider recommends.

“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 explained. “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.”

The Penn State study was limited, as data did not include Medicare patients, Medicaid patients, or the uninsured. In addition, the study involved a private insurance sample and patients younger than 65 years of age, so the findings cannot be generalized to those who are older.

To read more about this study, click here.

The Center for Applied Studies in Health Economics and Penn State College of Medicine funded this research.