Projections show Parkinson's disease cases will reach 25.2 million by 2050

By 2050, there will be 25.2 million people living with Parkinson's disease worldwide (a 112% increase from 2021), largely due to population ageing, suggests a modelling study published by The BMJ today.

Overall, the number of people living with Parkinson's disease (all age prevalence) per 100,000 population is predicted to increase by 76%, and by 55% when corrected for age differences (age standardised prevalence), with rates projected to be highest in East Asia.

The researchers say these projections "could serve as an aid in promoting health research, informing policy decisions, and allocating resources."

Parkinson's disease is the neurological disease with the fastest growing prevalence and disability, yet predictions of future prevalence in many countries and regions are still lacking.

To address this, researchers used data from the Global Burden of Disease Study 2021 to estimate the age, sex, and year specific prevalence of Parkinson's disease in 195 countries and territories from 2022 to 2050 and the factors driving changes in Parkinson's disease cases.

Globally, they estimate that the number of people living with Parkinson's disease in 2050 will be 25.2 million for all ages and both sexes combined, representing a 112% increase from 2021.

By 2050, cases of Parkinson's disease are projected to increase in all Global Burden of Disease regions, particularly in moderately developed countries in the middle range of the Socio-demographic Index (SDI) scale.

The researchers predict that population ageing will be the main driver (89%) behind this rise, followed by population growth (20%), with different patterns at the regional and national levels.

They estimate that the all age prevalence of Parkinson's disease will reach 267 cases per 100,000 in 2050 (243 for women and 295 for men), an increase of 76% from 2021, while the age standardised prevalence is expected to rise by 55% to 216 cases per 100,000.

The largest number of Parkinson's disease cases is predicted to be in East Asia (10.9 million), followed by South Asia (6.8 million), with the fewest cases in Oceania and Australasia.

The most pronounced increase in Parkinson's disease cases by 2050 is expected to occur in western Sub-Saharan Africa (292%), while the smallest increases (28%) are projected in central and eastern Europe, due to negative population growth and a smaller contribution from population ageing.

People aged over 80 are predicted to have the highest prevalence (2087 cases per 100,000) in 2050, while the gap in cases between men and women is also set to widen globally from 1.46 in 2021 to 1.64 in 2050.

Finally, the researchers estimate that increasing physical activity could reduce the future number of Parkinson's disease cases, whereas stopping smoking may lead to a rise in prevalence, but say these results should be interpreted cautiously.

As this is a modelling study, it has some important limitations, including low availability and quality of data in some regions, a lack of data on risk factors other than demographics, and being unable to accurately predict the prevalence of Parkinson's disease in various ethnic groups, or the impact of covid-19.

However, the researchers say that to the best of their knowledge, this study provides the first comprehensive projections of the global, regional, and national prevalence of Parkinson's disease until 2050.

"An urgent need exists for future research to focus on the development of novel drugs, gene engineering techniques, and cell replacement therapies that are aimed at modifying the course of the disease and improving patients' quality of life," they conclude.

In a linked editorial, researchers welcome this study but say adopting more advanced techniques may allow for better forecasting and ensure that healthcare systems, policy makers, and researchers are equipped with reliable data for long term planning.

"Future projections should prioritise methods that capture the true complexity of chronic disease progression, ultimately leading to more effective interventions and improved patient outcomes," they conclude.