Researchers are to investigate concerns that the cholesterol-lowering statin drugs might increase patients’ risk of Parkinson’s disease, according to a report in the magazine Chemistry and Industry.

A group at University of North Carolina led by Dr Xuemei Huang is planning a clinical trial involving thousands of people to examine if the drugs are

linked to the neurodegenerative disorder.

The move follows recent findings at the University suggesting that patients with low levels of LDL cholesterol are more than three and a half times more likely to develop Parkinson's disease than those with higher LDL levels.

Statins, the world’s best-selling drugs, which protect against arterial disease, work by lowering LDL cholesterol levels. Other scientists have reacted with scepticism to the suggestions of a link. However, Dr Huang said she was “very concerned” about the findings, “which is why I am planning a 16000-patient prospective study to examine the possible role of statins."

Parkinson's surge in the next five years?

Dr Huang is reported by the magazine as saying that a well-established link between Parkinson's and apoE2, a gene associated with lower LDL cholesterol, supports her theory that low LDL is the culprit in many cases of Parkinson's. She noted, however, that a causal link with statins had not yet been proven. Nonetheless, she said that if a link did exist then there could be a surge in the number of Parkinson's diagnoses in the next five years, because at that stage, statins will have been in common usage for more than a decade.

However, Dr Yoav Ben-Shlomo, a professor of clinical epidemiology at University of Bristol, said that it was possibile that LDL cholesterol was a consequence, rather than a cause, of Parkinson's.

Other leading clinicians and scientists were even more sceptical of a link between statins and the disease. Dr Patricia Limousin, a consultant neurologist at University College London’s Institute of Neurology, said: “There is absolutely no evidence that statin drugs cause Parkinson's disease.”

And Dr David Dexter, a senior lecturer in neuropharmacology at Imperial College London, added: “The study by Huang and colleagues indicating an association between lower LDL-c levels and Parkinson's disease goes against current scientific beliefs. Indeed, previous studies have demonstrated that statins can increase brain dopamine concentration, the chemical transmitter deficient in Parkinson's. “Lower LDL-C levels may also be a consequence of Parkinson's and not a cause. Indeed, the study did not take into account the dietary intake of the two groups in the study, this may be important since some Parkinson's patients find it difficult to eat or even swallow food thus reducing the intake of fats. Also the healthy subjects in the study had a higher usage of statins that those with Parkinson's which goes against any association." By Michael Day