Parkinson's disease is more common among individuals with a higher socioeconomic status and in the northern provinces of the Netherlands. In the southern provinces, Parkinson's occurs less frequently. Men are at greater risk than women, and the risk increases with age, peaking between 75 and 85 years. These findings come from a large-scale study by researchers at Utrecht University and Radboudumc on the number of new patients and the distribution of Parkinson's disease in the Netherlands between 2017 and 2022.
The study provides the first nationwide analysis of the annual number of new patients (incidence) and the spatial distribution of Parkinson's disease (PD) in the Netherlands. Researchers from Utrecht University and Radboud university medical center linked various health data to demographic and socioeconomic information. New Parkinson's diagnoses were calculated based on death certificates, medication prescriptions, health insurance claims, and hospital records.
The annual influx of new patients remains stable
The number of new patients per year (adjusted for population size) remains stable. The analysis shows that between 2017 and 2022, an average of 3,724 new Parkinson's diagnoses were made annually. The fact that the total number of Parkinson's patients in the Netherlands is increasing is due to people living longer with the disease. People tend to die with Parkinson's rather than from Parkinson's. This is partly thanks to the success of ParkinsonNet, a network of healthcare professionals specialized in caring for people with Parkinson's.
Significant regional differences
The study shows clear geographic differences: some regions have a higher risk than others. Parkinson's is more common in the north of the Netherlands than in the south. Researchers also found that the risk of PD is higher among men, highly educated individuals, and that the risk increases with age.
Role of environmental factors
An important question is how these differences can be explained. The geographic distribution of Parkinson's at the time of diagnosis does not clearly correspond to the distribution of potential risk factors, such as air pollution or certain types of agriculture. For example, air quality in the north of the Netherlands is relatively good. This does not mean there is no link with environmental factors. Each environmental factor individually has only a limited impact, but because almost everyone is exposed to them, they can collectively play an important role.
Moreover, the risk of Parkinson's is determined by exposure over a long period of at least 10 years, and likely much longer. In this study, the residential address at the time of diagnosis was considered. Links with specific environmental factors often become clear only when looking at individuals rather than entire regions, including their residential history. Therefore, further research at the individual level is necessary.
Follow-up research
Currently, the nationwide OBO2 program is underway, in which RIVM, Nivel, and the IRAS (Institute for Risk Assessment Sciences) at Utrecht University are investigating whether people can become ill or have become ill due to exposure to pesticides in the environment. Two additional studies also focus on Parkinson's disease. One of these is a collaboration between Radboudumc and IRAS, the so-called PD-PEST study. This study examines the role of pesticides and other environmental factors at the individual level. It is so far the largest case-control study on Parkinson's in the Netherlands.
About Parkinson's disease
In the Netherlands, about 63,000 people live with Parkinson's disease. This condition causes a wide range of symptoms, such as tremors, slowness of movement, muscle stiffness, and non-motor symptoms like mood disorders, sleep problems, and cognitive impairments. There is currently no cure for this progressive disease. It occurs because cells in the brain that produce dopamine die. The origin is still unknown, but various factors, including exposure to certain chemicals and genetic predisposition, likely play a role.
About this publication
This research was published in The Lancet Regional Health – Europe: Incidence and spatial variation of Parkinson's Disease in the Netherlands (2017–2022): a population-based study – Mariana Simões, Susan Peters, Anke Huss, Sirwan K.L. Darweesh, Bas Bloem, Roel Vermeulen. DOI: https://doi.org/10.1016/j.lanepe.2025.101565 .
