Public health studies that collect data from thousands of patients can allow researchers to find important patterns in human health. These epidemiological studies are especially powerful in countries that maintain databases on citizen health. A new study that paired laboratory research with one that assessed prescriptions in Norway over eleven years has shown that a prescription drug that treats asthma and a high blood pressure medication are both linked to the risk of developing Parkinson’s disease. This work has been reported in Science.
Researchers at Harvard University did a study in cell culture that identified candidate drugs. Their results guided a team at Department of Global Public Health and Primary Care (IGS) of the University of Bergen (UiB), who analyzed the effect of one thousand different drugs on Parkinson’s risk in the Norwegian population. Asthma medication was linked to a halving of the risk, while a drug that is used for high blood pressure is associated with a doubling of the risk. This work could impact how Parkinson’s disease is treated.
It is still not known exactly what causes Parkinson’s disease. It is a chronic, degenerative condition, in which cells in the brain that control the movements of the body are slowly destroyed. Symptoms often develop over a long period of time, making diagnosing the condition difficult. Poor coordination, shivering, and stiffness in the arms and legs are common features of the disease, which reduces longevity.
At Harvard, the research team looked drugs that reduced the expression of a gene called alpha-synuclein. A buildup of the protein that gene encodes for has been implicated in Parkinson’s disease. They found that agonists of the beta2-adrenoreceptor could potentially lower alpha-synuclein levels.
Indeed, two kinds of beta2-adrenoreceptor agonists affected Parkinson’s risk when the scientists queried the Norwegian prescription database. They showed how asthma medication salbutamol had the opposite effect of a type of blood pressure drug, beta-blockers, on the risk of developing Parkinson’s disease, confirming the findings in the laboratory. The dose of the drug was important, however; those individuals receiving the lowest doses showed a much milder effect.
It seemed that Norwegians who took salbutamol at least once in their lifetime were roughly a third less likely to get Parkinson’s. “Our analysis of data from the whole Norwegian population has been decisive for the conclusion in this study," noted Professor Trond Riise of IGS.
"We analyzed the whole Norwegian population and found the same results as in the animal testing at Harvard University. These medicines have never been studied in relation to Parkinson's disease," said Riise.
"Our discoveries may be the start of a totally new possible treatment for this serious disease. We expect that clinical studies will follow these discoveries,” concluded Riise.
These drugs have not yet been optimized for treating Parkinson’s, however. There is more work to be done before beta2-adrenoreceptor agonists are ready for use in the clinical as well; none of them can cross the blood-brain barrier.
In the video above, get an overview of how beta2-adrenoreceptor agonists work.