People who stop taking statins may be at an increased risk for developing Parkinsons disease, according to a Taiwanese study.
Previous studies on the relationship between statins and the risk of Parkinsons disease have had inconsistent results, researchers noted in background information for the study, which was published July 24 on the website of the journal Neurology.
The new study involved 43,810 people in Taiwan who were taking statins and did not have Parkinsons disease. Taiwans compulsory national health insurance program reimbursement policy requests that physicians stop prescribing statins once the patients cholesterol reaches the treatment goal, which is contrary to standard treatment in the United States.
“This policy allowed us to see whether there was any difference in the risk of Parkinsons in people who stopped taking statins compared to the ones who kept taking them,” the studys author, Jou-Wei Lin, MD, PhD, of National Taiwan University in Taipei, said in a news release.
The study found a difference between two types of statins. The use of lipophilic statins such as simvastatin and atorvastatin was associated with a reduced risk of Parkinsons, while no such association was found for hydrophilic statins such as pravastatin and rosuvastatin.
Those who stopped taking the fat-soluble statins were 58% more likely to develop Parkinsons disease than those who kept taking the drugs, an absolute risk of 2.65 cases per 1 million person-days. This result was consistent even after adjusting for other conditions such as diabetes and hypertension. The association was strongest among female users for simvastatin and among the elderly for atorvastatin.
The researchers also looked at how many people taking the two types of statins developed Parkinsons disease, compared with the number of person-days spent on the medication, to come up with an incidence rate.
A total of 25 people taking fat-soluble statins developed Parkinsons from a total of nearly 15 million person-days on the drugs, for a rate of 1.68 cases per 1 million person-days on the drugs. For the water-soluble statins, 14 people developed Parkinsons from nearly 4 million person-days on the drugs, for a rate of 3.52 cases per 1million person-days on the drugs.
“The fat-soluble statins are better able to cross the blood-brain barrier than the water-soluble statins,” Lin said.
Study abstract: www.neurology.org/content/early/2013/07/24/WNL.0b013e31829d873c.short