August 7, 2013
Ending Lipophilic Statin Therapy Can Raise Parkinson’s Disease Risk for Some Patients

Taipei, Taiwan—Discontinuation of lipophilic statin therapy can increase the risk of Parkinson’s disease (PD) in some patients, according to a new study involving more than 40,000 participants in Taiwan.

“Continuation of lipophilic statin therapy was associated with a decreased incidence of PD as compared to discontinuation in statin users, especially in subgroups of women and elderly,” according to the report published online recently by the journal Neurology. Study authors called for long-term follow-up studies to clarify the potential beneficial role of lipophilic statins in preventing Parkinson’s.

Contrary to standard treatment practices in the U.S., physicians in Taiwan are asked to stop prescribing statins when patients’ cholesterol levels reach the treatment goal. "This policy allowed us to see whether there was any difference in the risk of Parkinson's in people who stopped taking statins compared to the ones who kept taking them," said study author Jou-Wei Lin, MD, PhD, of National Taiwan University in Taipei.

Researchers found that patients who stopped taking the fat-soluble statins were 58% more likely to develop Parkinson’s disease than those who kept taking the drugs, an absolute risk of 2.65 cases per one million person-days, even after adjusting for comorbidities such as diabetes and high blood pressure.

“Among the 43,810 statin initiators, the incidence rate for PD was 1.68 and 3.52 per 1,000,000 person-days for lipophilic and hydrophilic statins, respectively. Continuation of lipophilic statins was associated with a decreased risk of PD (hazard ratio [HR] 0.42 [95% confidence interval 0.27-0.64]) as compared with statin discontinuation, which was not modified by comorbidities or medications,” the researchers report.

No such association was found for hydrophilic statins such as pravastatin and rosuvastatin.

Among lipophilic statins, however, a significant association was observed for simvastatin (HR 0.23 [0.07-0.73]) and atorvastatin (HR 0.33 [0.17-0.65]), especially in female users. The elderly subgroup appeared to benefit the most from atorvastatin usage (HR 0.42 [0.21-0.87]).

Study authors cautioned that “long-term use of statins, either lipophilic or hydrophilic, was not significantly associated with PD in a dose/duration-response relation.”

In terms of incidence rate, the researchers noted that 25 people taking fat-soluble statins developed Parkinson's disease from a total of nearly 15 million person-days on the drugs—a rate of 1.68 cases per one million person-days on the drugs—compared to 14 people taking water-soluble statins from nearly four million person-days on the drugs—a rate of 3.52 cases per one million person-days on the drugs.

In an accompanying editorial, commentators from medical facilities in Singapore write, “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.”

Noting the existence of a biological basis for the association between statin use and lower risk of Parkinson’s disease, the editorial called for more research to “further decipher the specific pathways or targets that are involved in statin-induced neuroprotection.”

U.S. Pharmacist Social Connect