Burden and Risk Factors of All-Cause Dementia in South Asia: An Analysis of Global Health Data and a Framework for Future Dementia Longitudinal Studies in Low-Resource Settings

Background: Dysregulated brain aging leads to dementia in some older adults. South Asia is one of the most populous regions of the world with a rapidly growing older adult population. Yet, very few studies have focused on quantifying the status and risk factors driving aging-related conditions such as dementia in this part of the world. Objectives: We explored multiple sources of global health data to quantify and compare all-cause dementia indices in South Asian countries. Design: Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka were considered. Population statistics and dementia as a priority area were examined using US Census Bureau and World Health Organization Global Dementia Observatory data. Crude and age-standardized rates (ASR) of dementia incidence, deaths and disability-adjusted life years (DALYs) were extracted and analyzed from the Global Burden of Disease (GBD) 2019 Study. Results: 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 [Crude DALYs, Sri Lanka = 321.52 (132.12–736.58); ASR DALYs, Afghanistan = 432.72 (179.01–1001.95)]. 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 in the region highlighted the role of metabolic dysregulation in dementia. Conclusions: Our preliminary analysis of available global health data highlights an emerging need for resources for dementia prevention and care in South Asia. There is also a critical need for future longitudinal follow-up studies focusing on dementia that are well-designed and can be harmonized with other dementia-related studies. We describe a roadmap for designing them—taking into account cultural, economic, public health and population aging dynamics that may be uniquely applicable to South Asian countries.