Mortality from Alzheimer’s disease and other dementias and its heterogeneity across states in India findings from GBD 2021 study

Dementia is a leading cause of death worldwide. This study examines trends and risk factors for dementia mortality in India and projects the future burden. Mortality and risk factors for Alzheimer's disease and other dementias (ADOD) in India between 1990 and 2021 were extracted from the Global Burden of Disease (GBD) 2021 database. Spatial autocorrelation analysis was calculated using ArcGIS 10.8. The age-period-cohort (APC) model was applied to analyze the independent effects of age, period and cohort. A bidirectional Mendelian randomization (MR) analysis assessed causality between risk factors and ADOD. The Bayesian APC model was conducted to predict future trends. From 1990 to 2021, deaths, crude mortality rates (CMRs) and age-standardized mortality rates (ASMRs) for ADOD increased gradually. Females had higher CMRs and ASMRs than males, and the burden persisted mainly in the elderly. In 2021, Uttar Pradesh, Maharashtra and Tamil Nadu were the top three states for deaths, but the top three states for ASMR were Meghalaya, Orissa and Telangana. Moreover, Meghalaya, Orissa and Telangana were also the three fastest growing states for ASMR. High fasting plasma glucose (FPG), high body mass index (BMI) and tobacco were the primary drivers of this increase. The MR analysis showed a statistically significant causal association of these three risk factors with ADOD. Projections showed that mortality in the elderly would continue to rise until 2050. Overall, the burden of dementia mortality in India has increased dramatically. There is an urgent need for targeted prevention and control strategies to reduce this burden.