Tuesday, April 10, 2012
statins dementia
Recently, statins have been shown to possess potent anti-inflammatory and immune-modulating effects, which fueled the hypothesis that statins could be neuroprotective agents, Dr. Gao and colleagues note in their report. Yet, prospective and epidemiologic studies to date have generated mixed results regarding statin use and PD risk, and the overall evidence for benefit "remains unconvincing," they say.
The researchers caution that their analysis has several limitations. Chief among them is the fact that they classified use of any cholesterol-lowering drugs before 2000 as statin use; as a result, misclassification was "inevitably introduced," they say. However, based on US retail prescription data, statins accounted for 72% of total cholesterol-lowering drug use in 1994, 80% in 1996, and more than 90% in 2000.
The lack of information on which specific statin drugs were used is another limitation. "We would like to test the effects of each specific statin as their ability to enter the brain varies and so they may have different effects on PD," Dr. Gao commented.
For example, lovastatin and simvastatin have been shown to have more potency to cross the blood-brain barrier relative to atorvastatin calcium. The researchers say it is likely that their results are driven by these 2 statins given that they were the most commonly prescribed in the mid-1990s.
The authors say they cannot exclude residual confounding because of the observational nature of the study.
Clearly more study is warranted, the researchers conclude, not only because statins may have neuroprotective effects, but also because they may have unfavorable effects by lowering the level of plasma coenzyme Q10, which may itself be neuroprotective in PD.
The study was supported by the National Institute of Neurological Disorders and Stroke. Dr. Gao has been a consultant for Teva Pharmaceuticals.
Arch Neurol. 2012;69:380-384. Abstract
