Status, determinants and risk factors of all-cause dementia in South Asia: Findings from a preliminary analysis of global health data

South Asia is one of the most populous regions of the world. At present, South Asians make up more than 25 percent of the world population but little effort has been dedicated to studying trends and etiological factors driving aging and aging-related conditions in this part of the world. Even less characterization has been done on brain-related conditions, particularly all-cause dementia in South Asia. To address this, we examined data from the US Census Bureau, World Health Organization Global Dementia Observatory and the Global Burden of Disease (GBD) 2019 Study, and conducted a comparative analysis of population statistics, dementia as a priority health area, and dementia incidence rates, death rates and disability-adjusted life years (DALYs) in 8 South Asian countries, Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka. Our analysis reiterated that there are limited resources dedicated to dementia in this region. Sri Lanka and Afghanistan had the highest dementia crude rates and age-standardized rates, respectively. The burden of dementia in some South Asian countries was comparable to estimated global averages, and was largely driven by population aging. Analyses of available data on known biological, behavioral, environmental and disease risk factors, highlighted the role of metabolic risk factors such as high fasting blood glucose. Here, we also underscore the critical need for future follow-up longitudinal studies focusing on brain aging and dementia and describe a roadmap for designing them - taking into account cultural, economic and public health dynamics that may be uniquely applicable to countries in South Asia. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement No funding sources to declare. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: All data used in the study were obtained from public sources and are listed in the manuscript. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All raw data can be downloaded from primary, publicly available data sources listed in the manuscript. All analyzed data and codes used for analysis are available upon request from corresponding author.