Incedence and prevalence of multiple sclerosis in China and other Asian countries

The prevalence of multiple sclerosis (MS) in Asian countries is thought to be lowerthan in Western countries, with Asian populations presenting 80% less risk of MS than whitepopulations. Incidence and prevalence rates in Asian countries are therefore not well definedand their association with rates in neighboring countries, as well as with ethnic, environmental, and socioeconomic factors, are not well understood. We performed a comprehensive literature review of epidemiological data from China andneighbouring countries to study the frequency of the disease, focusing on prevalence, and theprogression over time and the influence of sex-related, environmental, dietary, and sociocultural factors. Prevalence rates in China range between 0.88 cases/100,000 population in 1986 and 5.2cases/ 100,000 population in 2013, with a non-significant upwards trend (p =.08). The increaseobserved in Japan, where figures ranged between 8.1 and 18.6 cases/100,000 population washighly significant (p <.001). Prevalence rates in countries with predominantly white populationsare considerably higher and have increased over time, reaching 115 cases/100,000 populationin 2015 (r2= 0.79, p <.0001). In conclusion, the prevalence of MS in China appears to have risen in recent years, althoughAsian populations (including Chinese and Japanese populations, among others) appear to present less risk than other populations. Within Asia, geographical latitude appears not to be adetermining factor for developing MS. (c) 2020 Sociedad Espa(similar to)nola de Neurolog ' ia. Published by Elsevier Espa(similar to)na, S.L.U. This is an openaccess article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/ 4.0/).