Table 1.

Available data on the effect of statins on PD, the role of HMGCR variants in statin treatment, and unanswered questions in the field. PD—Parkinson’s disease, LDL-C—low-density lipoprotein cholesterol.

Statins in PD	Influence of HMGCR Variants on Statin Treatment	Questions Raised
statins exert protective function against PD [12,39]; significant protective effect is linked to atorvastatin [39]; progression of the motor symptoms in PD is slower in statin users [68]; statin users experience lower cognitive decline [67].	haplotype 7 (rs17244841, rs17238540, and rs3846662) is associated with reduced change in LDL-C level upon statin treatment [71,72]; conflicting results of HMGCR rs3846662 major allele (correlated with splicing defect) in terms of statin treatment responses [75,76,77]; HMGCR rs17238540 polymorphism is associated with lower reduction in total cholesterol level [78].	neuroprotive actions of statins may differ depending on the statin used [12,39]; ambiguous role of cholesterol in PD [13,24,25,26,29,31,33,34,35]; HMGCR variants may influence baseline LDL-C level [77], statin treatment [71,72,75,76,77,78] and possibly their neuroprotective effects.