Inhaled beta-2 agonists not linked to lower risk of Parkinson's disease: Study

Kuopio [Finland], June 14 : Bronchodilators known as beta-2 agonists are extensively used in the treatment of asthma and chronic obstructive pulmonary disease (COPD). Although beta-2 agonists have been linked to a lower incidence of Parkinson's disease in earlier research, this link was not detected in a recent register-based investigation from the University of Eastern Finland.

The findings of the study were published in Clinical Epidemiology.

The accumulation of the protein alpha-synuclein in the brain is a key factor in Parkinson's disease. In animal and cell models, beta-2 agonists were discovered to reduce the expression of the alpha-synuclein gene, which might be advantageous in Parkinson's disease. Furthermore, despite previous epidemiological research linking beta-2 agonists to a lower incidence of Parkinson's disease, confounding variables such as smoking may have impacted this connection.

Smoking is the leading cause of COPD, and it may worsen asthma control and result in an increased need of beta-2 agonists. However, smoking is also associated with a reduced risk of Parkinson's disease, making it important to control for confounding factors in the study setting. Although nationwide Finnish register data do not contain information on smoking, its impact may be controlled for by restricting the study on individuals among whom smoking history is more likely to be evenly distributed.

According to the newly published case-control study among people diagnosed with asthma or COPD, the use of inhaled short- or long-acting beta-2 agonists at least three years before Parkinson's disease diagnosis was not associated with the risk of Parkinson's disease. There was no consistent dose-response association either. Different comorbidities such as cardiovascular diseases, along with age, sex and duration of asthma or COPD were controlled for in the study.