A new modeling study predicted that the global prevalence of Parkinson's disease will more than double by 2050, reaching an estimated 25.2 million cases worldwide.

Published in The BMJ, the study was based on the Global Burden of Disease Study 2021. Investigators attributed this sharp increase primarily to population aging, with additional contributions from population growth and changes in disease prevalence.

They projected a 76% increase in all-age prevalence, rising to 267 cases per 100,000 individuals by 2050. The age-standardized prevalence was expected to grow by 55% to 216 cases per 100,000. Population aging was predicted to contribute 89% to the growth in cases from 2021 to 2050, followed by population growth (20%) and changes in prevalence (3%).

The highest number of Parkinson's disease (PD) cases was predicted in East Asia, with 10.9 million cases projected by 2050. Western Sub-Saharan Africa may see the largest percentage increase (292%), whereas the lowest increases were anticipated in central Europe (28%) and eastern Europe (28%). The investigators highlighted disparities in prevalence growth among sociodemographic groups, noting that middle Socio-demographic Index countries could experience the greatest relative increase in both all-age prevalence (144%) and age-standardized prevalence (91%).

The ≥80 years age group was projected to see the highest increase in cases (196%) from 2021 to 2050. The male-to-female ratio of age-standardized PD prevalence was projected to rise from 1.46 in 2021 to 1.64 in 2050, with men consistently exhibiting higher prevalence rates.

The investigators also examined modifiable risk factors, estimating that if all individuals adhered to regular physical activity, PD cases could be reduced by 4.9%. Conversely, if all individuals stopped smoking, PD cases could increase by 10.6% due to smoking's reported inverse association with disease risk.

"By 2050 Parkinson's disease will have become a greater public health challenge for patients, their families, care givers, communities, and society," the investigators concluded. "This projection could serve as an aid in promoting health research, informing policy decisions, and allocating resources."

The study was supported by grants from the National Nature Science Foundation of China. Full disclosures are detailed in the study.