Parkinson's disease

[Al-khiyal]

The link between a popular anti-cholesterol drug and Parkinson's, a degenerative brain disease, is to be examined in depth as health officials urge patients at risk of heart attacks to keep taking the medicine.

Cholesterol-lowering statins are taken by an estimated three million Britons and are renowned for preventing heart attacks and strokes.

But scientists are planning a detailed study after research showed a link to Parkinson's, which affects around 120,000 people in the UK.

Charities urged people to continue taking their statins, saying the drugs saved lives.

According to a report in Chemistry & Industry, researchers in the US plan a large-scale clinical trial on the link.

Experts at the University of North Carolina said they had found the strongest link yet between Low-density lipoprotein (LDL) cholesterol levels and Parkinson's.

High levels of LDL cholesterol are linked to heart disease. Statins are known to reduce these LDL levels.

Professor Peter Weissberg, medical director of the British Heart Foundation, said: "Nobody should stop taking statins on the basis of this report. If they do, they will be putting themselves at increased risk of heart attack or stroke."

Cholesterol drug link to Parkinson's disease

[Al-khiyal]

Chemistry & Industry

[Al-khiyal]

· Fears that statins could cause increase in illness

· Health charities urge caution over findings

Scientists are to investigate why people with low cholesterol levels appear to be more likely to develop Parkinson's disease, following concerns that statins - given to control cholesterol - could cause an increase in the numbers of people with the illness.

About 2.3 million adults in the UK take statins to help control their cholesterol levels; the American scientists have found that those with lower levels of cholesterol are more likely to develop the degenerative neurological disorder of Parkinson's disease.

The link between statins and Parkinson's is not yet understood, and health charities last night urged caution. But the scientists behind the research warn that if they get confirmation of the finding, in their follow-up study of 16,000 people, there could be a surge in Parkinson's diagnoses in the next five years as the effects of the drug set in.

The initial study compared 124 people diagnosed with Parkinson's with a control group of 112. They found that the people with low levels of "bad" LDL cholesterol were in excess of three times more likely to be in the Parkinson's group than those with high cholesterol.

But they also found that those in the trial who took statins were less likely to develop Parkinson's disease, though the study's leader suggested this could be because the group with Parkinson's had had low cholesterol all their lives and that the effect of low cholesterol could be cumulative.

Statins are the world's biggest selling drug. The drug company Pfizer reported sales of $12.2bn (£6.2bn) for its statin, Lipitor, in 2005. The National Institute for Clinical Excellence last year recommended more people take them in the UK, raising the number of customers from 2.3 million to 5.2 million.

The head of the study, Xuemei Huang, at the University of North Carolina, said: "I'm definitely concerned [about the initial findings] which is why I'm conducting a prospective study of 16,000 people."

People should not stop taking statins, she said. The risk of heart disease in those who should be taking statins far outweighed the risk of developing Parkinson's.

The study, which is reported today in the journal Chemistry and Industry, has raised more questions than it has answered. It has not, for example, established whether low cholesterol is a cause or consequence of Parkinson's.

David Dexter, senior lecturer in neuropharmacology at Imperial College London, said: "Although the association is worrying, the study was carried out only in a small number of subjects and hence needs confirming in a larger population. 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, [which] may be important since some Parkinson's patients find it difficult to eat or even swallow food, thus reducing the intake of fats."

Dr Huang said the well-established link between Parkinson's and apoE2, a gene associated with lower LDL cholesterol, supported her theory that low LDL was the culprit in many cases of Parkinson's.

Kieran Breen, director of research at the Parkinson's Disease Society, said people should be wary of such a small study. "Further research into any link between low LDL cholesterol and cholesterol-lowering drugs with Parkinson's is needed. We hope that the proposed study will shed further light on this. The exact causes of Parkinson's are unknown. Research is ongoing. It is generally understood that Parkinson's [arises] from genetic and environmental factors."

Peter Weissberg, medical director of the British Heart Foundation, said: "We are concerned that any suggestion of a link between statins and Parkinson's disease would unnecessarily scare the millions of people benefiting from statins in the UK. There is no evidence to suggest that statins cause [the] disease. On the other hand, there is overwhelming evidence that statins save lives by preventing heart attacks and strokes."

Low cholesterol levels linked with higher risk of Parkinson's disease

[Al-khiyal]

June 11, 2007 -- A common drug used to treat high blood pressure could slow the devastating physical decline experienced by people who suffer from Parkinson's disease, researchers will say today. A study of the drug, isradipine, which is widely used to treat hypertension and stroke, suggests it could also be used as a prophylactic against the disease.

The scientists say the drug stalled the progression of the disease in mice, but they have yet to carry out human tests. They are at the stage of planning large-scale clinical trials.

Patient groups in the UK welcomed the findings, published in the journal Nature, but emphasised these were early results and some way off a cure.

"Our hope is that this drug will protect dopamine neurons, so that if you began taking it early enough you wouldn't get Parkinson's disease, even if you were at risk," said James Surmeier, who leads the Morris K Udall Centre of Excellence for Parkinson's Disease Research, at Northwestern University, based in Chicago. "It would be like taking a baby aspirin everyday to protect your heart."

About one in 500 people in the UK has got Parkinson's disease, and the rate soars in those over the age of 60. The symptoms develop over months or years and include tremors, stiffness, immobility and speech problems, which worsen over time. The main drugs used for it manage the symptoms but are less effective as the disease progresses. It is hoped that by delaying progression the drug might offer a longer time during which anti-tremor drugs could be given.

The disease affects the flow of the brain's dopamine, which is crucial to muscle function. The drug in the US study blocked the interplay between dopamine and calcium, hinting at a new understanding of the mechanisms that cause Parkinson's. The researchers found that isradipine, which acts as a "calcium blocker", could rejuvenate ageing dopamine neurons.

"This lowers the cells' stress level and makes them much more resistant to any other insult that's going to come along ... they start acting like they're youngsters again," Dr Surmeier said.

The mice tests showed that the drug protected the dopamine cells from lethal toxins; the mice, engineered to have a progressive Parkinson's-like disease, resisted becoming ill.

Kieran Breen, director of research and development at the Parkinson's Disease Society, said the drug appeared "to slow or stop the death of nerve cells in the brain, in a model of Parkinson's".

But he added: "It is too early to state with confidence that this drug will be appropriate for the treatment ... we can also not predict whether this drug will be used as a preventative or protective measure. A significant amount of further research will be required before any definite conclusions can be drawn."

· This article was amended on Friday June 15 2007. We mistakenly quoted a figure of one in 200 people in the UK as having Parkinson's disease, but most charities in the field say the incidence is closer to one in 500. This has been corrected.

Blood pressure drug may help stall Parkinson's say researchers

[Al-khiyal]

November 20, 2007 -- The first gene-based therapy for Parkinson's disease has been found to be effective following brain scans of patients who received the treatment as part of an on-going trial. The success marks an important landmark for gene therapy, which has never before been used to treat a degenerative brain disease in humans.

In the study, patients' brains were injected with a harmless virus, genetically modified to carry a human gene which dampens down nerve cells that become overactive in Parkinson's patients, interfering with movement control.

Doctors noted a significant improvement, and the scans confirmed the treatment worked by highlighting brain circuits involved in movement that had recovered. Eleven men and one woman received injections directly into part of the brain most affected by the disease. The scans later showed that some brain circuits that act abnormally in Parkinson's patients were working healthily again.

The patients showed signs of recovery one month after treatment, and three to six months later showed on average a 30% improvement in their movement. One patient's recovery astounded doctors, after tests showed his movement had improved 65%.

"These scans show that the treatment corrects abnormal activity in the brain, and we would only see those changes if the therapy was working," said Dr David Eidelberg, who led the study at the New York University School of Medicine.

Before scanning the patients' brains, it was unclear whether their recovery could be explained by the placebo effect, or even by the surgery to enable doctors to inject the gene-based drug into their brains. Detailed examination of the scans showed very specific changes in the patients' brains that could only be explained by the therapy, Eidelberg said.

Parkinson's affects around 120,000 people in Britain, with 10,000 new cases diagnosed each year. Symptoms, such as tremors, difficulty in moving and muscles that tighten and lock, usually appear when a patient is over 50.

There is no cure and while several drugs are available to treat symptoms, some patients experience side-effects, among them a condition called dopamine dysregulation syndrome. Patients affected by the condition demand increasing doses of medication, are prone to aggressive outbursts and indulge in risky behaviour.

The disease is caused by a loss of nerve cells in one part of the brain. The cells release a chemical called dopamine, which allows messages to be sent to parts of the brain that coordinate movement. As the dopamine-producing cells die off, these parts of the brain stop functioning properly.

At the same time, levels of another chemical messenger, which dampens down over-active cells, begin to drop.

It is levels of this chemical that were boosted in the study when regions of patients' brains were injected with a genetically modified virus to carry a human gene which is absorbed by nerve cells. The brain scan images revealed how the activity of different brain circuits changed before and after treatment.

The team found changes in several parts of the brain, notably the circuits that control movement. Networks of nerve cells linked to cognitive ability, that also deteriorate in Parkinson's patients, showed no sign of improvement. The study appears in the journal Proceedings of the National Academy of Sciences today. The doctors are planning a second, larger trial of the therapy, due to begin early next year and expected to last 18 months.

Genetically altered virus helps Parkinson's sufferers

[Al-khiyal]

December 12, 2007 -- First-degree relatives - parents, siblings and children - of people with Parkinson's disease are about 50 percent more likely than relatives of healthy people to suffer depression or anxiety, a new study reports.

That relatives of people with Parkinson's have a higher risk of neurological disorders is well known, but their risk for psychiatric disorders has been unclear.

Researchers studied 1,000 first-degree relatives of 162 people with Parkinson's and 850 first-degree relatives of 147 healthy people. The team found a 45 percent increased risk for depressive disorders and a 55 percent increased risk for anxiety disorders among the Parkinson's relatives.

The study, published in the December issue of The Archives of General Psychiatry, also found that the earlier the onset of Parkinson's, the more likely a relative was to suffer depression.

Parkinson's raises risk of depression in family