The global prevalence of Parkinson disease (PD) is projected to more than double by 2050, with aging populations as the leading contributor to this rise, according to the findings of a study published in The British Medical Journal (BMJ).

Researchers utilized data from the Global Burden of Disease Study 2021 to estimate the future prevalence of PD across 195 countries and territories. They aimed to quantify the influence of demographic trends, including population aging and growth, and to evaluate how changes in prevalence rates and modifiable risk factors, such as smoking and physical activity, may shape the future landscape of PD.

Projections indicated that the number of people living with PD will rise from 11.9 million in 2021 to 25.2 million by 2050, an increase of 112% (95% uncertainty interval, 71%-152%). This surge is anticipated to be largely attributable to population aging (89%), with smaller contributions from population growth (20%) and prevalence changes independent of demographic shifts (3%).

In 2050, the global age-standardized prevalence of PD is expected to reach 216 per 100,000 people, reflecting a 55% increase from 2021. The all-age prevalence is projected to be even higher, at 267 per 100,000 (a 76% increase), highlighting the outsized impact of an aging global population. The greatest rise in PD cases is anticipated among adults aged 80 years and older, with a 196% increase in absolute case numbers between 2021 and 2050.

Public health interventions, which may alter the prevalence of risk/protective factors, offer promising prospects for arresting the universal rise in prevalence of Parkinson’s disease in the future.

Baseline characteristics revealed key sociodemographic disparities. Countries in the middle quintile of the Socio-demographic Index, which measures income, education, and fertility, are expected to see the highest increases in both all-age (144%) and age-standardized (91%) PD prevalence. East Asia is forecasted to house the largest number of PD cases by 2050 (10.9 million), while western Sub-Saharan Africa may experience the steepest relative increase in cases (292%).

Sex-specific projections showed that although both men and women will experience increases in PD prevalence, the male-to-female ratio of age-standardized prevalence is expected to rise from 1.46 to 1.64 by 2050. Men are projected to have higher age-standardized prevalence across all age groups, despite women representing 46% of PD cases overall.

Among modifiable risk factors, smoking and physical inactivity were evaluated for their impact. However, even if exposure to these factors were entirely eliminated, the resulting change in prevalence would be modest relative to demographic drivers.

Study limitations included limited risk factor data, reliance on smoking and physical inactivity metrics, regional data quality issues, and the inability to account for genetic, ethnic, and diagnostic variations in PD prevalence.

“Public health interventions, which may alter the prevalence of risk/protective factors, offer promising prospects for arresting the universal rise in prevalence of [PD] in the future,” the researchers concluded.

This research was supported by the National Nature Science Foundation of China.

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