Previous studies have confirmed that the duration of physical exercise has a direct impact on Parkinson’s disease (PD); however, the relationship between modes of exercise and PD risk remains unclear. A recent npj Digital Medicine study used data obtained from the United Kingdom Biobank to explore the relationship between PD risk and different exercise patterns.

Study: Association of Physical Activity Pattern and Risk of Parkinson’s Disease. Image Credit: Harbucks / Shutterstock.com

How exercise influences PD risk

PD is a neurodegenerative disease that is characterized by postural instability, slow movements, muscle tonus, and resting tremors. Environmental factors, genetic predisposition, and lifestyle, including daily exercise, can influence the development of PD.

PD primarily affects individuals 50 years of age and older. By 2030, researchers estimate that the number of individuals affected by PD will reach 8.7-9.3 million worldwide. Thus, given the rising burden of PD, it is imperative to identify risk factors early and devise preventive interventions.

Increasing evidence indicates the significant benefits of exercise in PD patients. About 150 minutes of moderate-to-vigorous physical exercise (MVPA) each week is recommended by the World Health Organization guidelines.

Research has shown similar efficacy of two specific exercise patterns in reducing the risk of cardiovascular disease and depression. However, the role of certain exercise patterns in mitigating the risk of PD has not been explored.

About the study

The researchers of the current study assessed the relationship between different exercise patterns and the incidence of PD. Data were collected at 22 locations in Wales, Scotland, and England using physical and functional assessments, interviews, touchscreen surveys, and genetic and biological procedures.

An initial sample of 502,389 individuals was selected from the U.K. Biobank. Incomplete exercise data and pre-existing PD excluded 402,282 and 1,000 individuals, respectively. An additional 10,607 participants were excluded due to missing data on covariates, resulting in the final study cohort comprising 89,400 individuals.

Study participants were categorized into inactive and active groups. The active group was further subdivided into weekend warriors (WW) and active regulars, who participated in weekly exercise for one to two days or exercise spread throughout the week, respectively.

To obtain exercise data, the Axivity AX3 wrist-worn triaxial accelerometer was used. A multifactorial Cox model was used to determine the relationship between the different exercise patterns and the risk of PD.

Study findings

During an average follow-up of 12.32 years, 329 individuals developed PD. Both the WW and active regular exercise patterns were significantly related to a reduced risk of developing PD.

The onset of PD was equally well prevented by the choice of maintaining an even distribution of exercise time or being a WW. This observation suggests that the duration of exercise could have a greater impact on reducing PD risk than the frequency of exercise.

Sub-group analyses were conducted for five covariates, including drinking status, sex, family history, diabetes, and blood pressure status. No significant interaction was noted between exercise and these factors.

Previously, one study reported that higher levels of exercise could reduce PD risk in men but not women. Contrary to this, another study conducted in the United States documented the beneficial effects of exercise on PD risk in both men and women. Likewise, the current study reported a similarly reduced risk of PD in physically active men and women as compared to those who were inactive.

Limitations

A key limitation of the current study is that the U.K. Biobank only captured one week of exercise time for each participant. Since multiple measurements were not recorded, it is possible that individuals’ behavioral patterns changed during the week they were monitored and may not be representative of their actual activity patterns, which is otherwise known as the Hawthorne effect.

Another limitation is due to the wrist-worn Axivity AX3 device used to obtain measurements. The Axivity AX3 cannot capture exercise data accurately for certain activities, leading to measurement errors.

The U.K. Biobank cohort is comprised mainly of white participants, with other racial groups in the minority, which may limit the generalizability of the findings. Therefore, additional research on more diverse populations is needed to validate these observations.

Robustness analyses on the motion data obtained from the wristwatch accelerometer are also needed to determine whether this data is consistent with data obtained through other methods. The current study’s small number of PD cases could have biased sub-group analyses for certain covariates, such as ethnicity.