Some Cholesterol Drugs May Lower Parkinsonís Risk
- Jul 23 2013
Drugs called statins such as atorvastatin (Lipitor®) and simvisatin (Zocor®) are commonly-prescribed to bring down cholesterol levels. A new study suggests that these drugs may protect brain cells from Parkinson’s disease, finding that when people on certain statins stop taking them, their risk of developing Parkinson’s disease (PD) is higher. The research appears in the July 24 online edition of Neurology.
Statins are among the most widely-used drugs around the world. Beyond lowering cholesterol, they are known to fight inflammation and oxidative stress — two things that may contribute to PD at the cellular level. Yet earlier studies seeking links between PD risk and statin use have provided conflicting results.
Researchers led by Jou-Wei Lin, M.D., Ph.D., at National Taiwan University in Taipei, studied the health records of 43,810 people aged 50 and older who began taking statins for the first time between 2001 and 2008, and who did not have PD at that time. In Taiwan, physicians are required to stop prescribing statins when a person’s cholesterol levels are lowered sufficiently (this is not the case in the US), so the researchers were able to identify people who stopped taking statins during the study period. In addition, the medical records included PD diagnoses.
- Between 2001 and 2009, a total of 1,985 study participants were diagnosed with PD.
- The researchers found a different PD risk in people who were prescribed different types of statins. Statins can be divided to those that are water-soluble, for example, pravastatin (Pravachol®) and rosuvastatin (Crestor®), and those that are fat-soluble including simvastatin (Zocor®) and atorvastatin (Lipitor®). It is estimated that those that are fat-soluble are more likely to penetrate the brain and therefore have more effect over the brain.
- People who started taking water-soluble statins at the beginning of the study had an average incidence of PD: 3.52 new cases per 1,000,000 person-days on the medication.
- People who started taking fat-soluble statins at the beginning of the study had a lower than average incidence of PD: 1.68 new cases per 1,000,000 person-days on the medication.
- People who stopped taking the fat-soluble statins were 1.58 times more likely to develop PD than those who continued taking the drugs.
What Does It Mean?
The new study reinforces the idea that certain statins should be investigated for potential neuroprotective effects, or the ability to protect neurons from PD. Given the epidemiological nature of this study, scientists cannot tell the mechanism by which statins may be neuroprotective. Therefore, scientists need to return to the bench to identify the ways in which statins may help prevent PD in order to move forward and create drugs specifically targeting PD.
Strengths of this study include the wealth of available data, and the large number of people who participated. However, the researchers did not examine the participants who were diagnosed with PD and could not account for lifestyle factors such as cigarette smoking and caffeine intake, both of which have been associated with lower PD risk.
In addition, because health information from this national database was anonymized, the authors were not able to confirm each diagnosis of PD. This can be of concern since some of the drugs used by the study participants could cause side-effects that mimic PD, leading to a question surrounding the accuracy of the PD diagnosis reported. However, the authors did try to account for this in their data analysis.
More research is needed to confirm these results, and to understand the potential benefit of statins in PD. In the future, clinical studies may be designed to assess lipid soluble statins as disease modifiers. Data from such trials will be essential, especially before individuals at-risk take these medications for preventive effects.
Additional PDF Commentary
To learn more about this study, see reactions below from two members of the PDF team, James Beck, Ph.D., Vice President, Scientific Affairs, and Phil Myers, Research Advocate from Lakeport, CA.
- "This research is a prime example of how existing drugs on the market have the potential to positively impact PD. For the one million people with Parkinson's disease in the US who need better treatments now, this is good news. However, we must remember that without a solid footing of how statins and similar drugs work, widespread testing or use of these drugs are like an expensive house built upon sand: it will be of little scientific benefit if it meets failure. We need scientists conducting the basic science to understand the drugs, if they are to be of benefit over the long-term."-James Beck, Ph.D., Vice President, Scientific Affairs, Parkinson's Disease Foundation.
- "As a PDF Research Advocate and a person living with Parkinson's disease, I was greatly encouraged by this study. The community is impatient for treatments that can stop this disease in its tracks. Understanding why statins may be protective can help us on our journey to find those treatments we so fervently desire. If researchers and patients work together, we can get there, but insights from the Parkinson’s community are crucial to ensure research meets community needs." -Phil Myers, Lakeport, CA, Research Advocate, Parkinson's Disease Foundation.
Reference: Lee Y-C, Lin C-H, Wu R-M, Lin M-S, Lin J-W, Chang C-H, Lai M-S (2013) Discontinuation of statin therapy associates with Parkinson disease: A population-based study. Neurology 81:410–416.
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Source Date: Jul 23 2013