Global, regional, and national burden of multiple sclerosis 1990 to 2021: A systematic analysis for the Global Burden of Disease Study 2021

BackgroundMultiple sclerosis (MS) is an autoimmune disease resulting from the immune system mistakenly attacks the brain and spinal cord. In recent decades, the prevalence of MS has increased, leading to a significant global health burden. MethodsThe study presented a comprehensive analysis of the incidence, prevalence, deaths, and disability-adjusted life years (DALYs) in MS using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021. Subsequently, Mendelian randomization (MR) was employed to investigate potential risk factors associated with MS. Finally, the Bayesian age-period-cohort (BAPC) model was used to predict the future trend of MS. ResultsFrom 1990 to 2021, the cases of MS increased from 1,004,659 to 1,887,767, while the age-standardized rate (ASR) remained relatively stable. Areas with higher Socio-demographic Index (SDI), such as Western Europe and High-income North America, exhibited a greater disease burden, whereas areas with lower SDI exhibited a higher ASR growth. The highest incidence rate was observed in individuals aged 30 to 34 years. The number of cases in females was approximately twice that in males. In addition to smoking, other risk factors, including body mass index, waist circumference, high-density lipoprotein cholesterol, and overweight, were identified by MR. It is anticipated that the ASIR of MS will continue to remain at a relatively high level until 2050. ConclusionsThe burden of MS was increasing globally, with variations observed across different geographies, sexes, and age groups, presenting a significant challenge to public health. This study provided a comprehensive investigation into the burden of MS, which would assist in the allocation of resources and the development of targeted prevention and control strategies.