Continued lipophilic statin therapy was associated with a decreased incidence of Parkinson's disease compared to starting and then stopping therapy, especially among female and elderly patients, a study found.
Researchers in Taiwan recruited patients without Parkinson's disease who started statin therapy between 2001 and 2008. Results were published online July 24 by Neurology.
Among the 43,810 patients who began taking statins, the incidence rate for Parkinson's disease was 1.68 per 1 million person-days for lipophilic statins (lovastatin, fluvastatin, simvastatin, atorvastatin) and 3.52 per 1 million person-days for hydrophilic statins (pravastatin, rosuvastatin). Continued statin therapy was associated with a decreased risk of Parkinson's disease (hazard ratio [HR], 0.42; 95% CI, 0.27 to 0.64) compared to stopping statins.
There was no association between use of hydrophilic statins and incidence of Parkinson's disease, researchers wrote. Among lipophilic statin users, there was a significant benefit to continuing simvastatin (HR, 0.23; 95% CI, 0.07 to 0.73) and atorvastatin (HR, 0.33; 95% CI, 0.17 to 0.65), especially in women (simvastatin: HR, 0.11, 95% CI, 0.02 to 0.80; atorvastatin: HR, 0.24; 95% CI, 0.09 to 0.64). Researchers also noted a beneficial effect in patients over 65 (HR, 0.42; 95% CI, 0.21 to 0.87). However, long-term use of either type of statin did not show a statistically significant dose or duration response effect on Parkinson's disease.
The researchers also looked at the relationship between stopping or continuing statins and mortality. Continuing lipophilic statins resulted in a significantly decreased risk of death compared to stopping them (HR, 0.31; 95% CI, 0.18 to 0.54), but this was only a trend for hydrophilic statins (HR, 0.48; 95% CI, 0.23 to 1.00).
The researchers wrote, “Since PD [Parkinson's disease] is a neurodegenerative disorder with a long pre-symptomatic period, there may be a window of opportunity for modification of the disease process before onset of motor symptoms. In this context, we speculated that lipophilic statins may act through modifying the level or sensitivity of dopamine receptors in striatum, rather than holding the neuronal degeneration process.”
An editorial noted that while there may be a biological basis for statins reducing Parkinson's disease, more research is needed to identify exactly what mechanisms are at work, including genetic factors. The editorialists wrote, “Current clinical and experimental data provide some compelling evidence that the benefits of statins probably extend beyond their anti-hyperlipid therapeutic effect. For those who have to be on statins, it is a comforting thought that there is a potential added advantage of having a lower risk of PD, and possibly other neurologic disorders as well.”