Statins and the risk of Parkinson disease : an update on the controversy

BACKGROUND: Parkinson disease (PD) is the second most common neuro- degenerative disease and the number of affected patients is growing. Until now, information on either risk factors (genetic or environmental) or neuro- protective agents is still scarce. Recently, hydroxymethylglutary-coenzyme A reductase inhibitors have been related to protective as well as to potential harmful effects with regard to the development of a PD diagnosis. OBJECTIVE: To give an overview and comment on the data available so far on this topic. METHODS: Relevant literature was identified using a PubMed search of articles published up to October 2008. Search terms included: 'Parkinson disease', 'statins', and 'epidemiology'. Original articles were reviewed and relevant citations from these articles were also considered. RESULTS/CONCLUSION: Results of the available observational studies were inconsistent with most studies reporting a protective effect of statins on the risk of PD. Others found no altered risk of PD in statin users compared to non-users or even an increased risk. Studies largely varied in size and analysis methods. Thus, comparison of the results is difficult. Until now, no definite conclusion on this topic can be made.