Global, regional, and national burden of Alzheimer's disease and other dementias, 1990-2019

Abstract

Background: With the increase in the aging population worldwide, Alzheimer's disease has become a rapidly increasing public health concern. Monitoring the dementia disease burden will support health development strategies by providing scientific data.

Methods: Based on the data obtained from the 2019 Global Burden of Disease (GBD) database, the numbers and age-standardized rates (ASRs) of incidence, prevalence, death, and disability-adjusted life-years (DALYs) of Alzheimer's disease and other dementias from 1990 to 2019 were analyzed. Calculated estimated annual percentage changes (EAPCs) and Joinpoint regression analyses were performed to evaluate the trends during this period. We also evaluated the correlations between the epidemiology and the sociodemographic index (SDI), an indicator to evaluate the level of social development in a country or region considering the education rate, economic situation, and total fertility rate.

Results: From 1990 to 2019, the incidence and prevalence of Alzheimer's disease and other dementias increased by 147.95 and 160.84%, respectively. The ASR of incidence, prevalence, death, and DALYs in both men and women consistently increased over the study period. All the ASRs in women were consistently higher than those in men, but the increases were more pronounced in men. In addition, the ASRs of incidence, prevalence, and DALYs were positively correlated with the SDI. Moreover, the proportion of patients over 70 years old with dementia was also positively correlated with the SDI level. Smoking was a major risk factor for the disease burden of dementia in men, while obesity was the major risk factor for women.

Conclusion: From 1990 to 2019, the Alzheimer's disease burden increased worldwide. This trend was more serious in high-SDI areas, especially among elderly populations in high-SDI areas, who should receive additional attention. Policy-makers should take steps to reverse this situation. Notably, women were at a higher risk for the disease, but the risk in men showed a faster increase. We should give attention to the aging population, attach importance to interventions targeting dementia risk factors, and formulate action plans to address the increasing incidence of dementia.

Keywords: Alzheimer's disease and other dementias; Global Burden of Disease; age-standardized rate (ASR); estimated annual percentage change; risk factors.

Figure 1

Distribution of the incidence of Alzheimer's disease and other dementias in 204 countries and territories from 1990 to 2019 by age group and SDI region. (A) Incidence rate in each age group. (B) Correlations between the ASIRs of Alzheimer's disease and other dementias and SDI regions in 2019. Associations were calculated with Pearson correlation analysis. (C) The ASIRs of 204 countries and territories. (D) EAPCs in the ASIRs in 204 countries and territories. SDI, sociodemographic index; ASIR, age-standardized incidence rate; EAPC, estimated annual percent change.

Figure 2

Distribution of the prevalence of Alzheimer's disease and other dementias in 204 countries and territories from 1990 to 2019 by age group and SDI region. (A) Prevalence rate in each age group; (B) Correlations between the ASPRs of Alzheimer's disease and other dementias and SDI regions in 2019; associations were calculated with Pearson correlation analysis; (C) The ASPRs in 204 countries and territories; (D) EAPCs in the ASPRs in 204 countries and territories. SDI, sociodemographic index; ASPR, age-standardized prevalence rate; EAPC, estimated annual percent change.

Figure 3

Distribution of deaths due to Alzheimer's disease and other dementias in 204 countries and territories from 1990 to 2019 by age group and SDI region. (A) Death rate in each age group; (B) Trends of the ASDRs in the SDI region; (C) ASDRs in 204 countries and territories; (D) EAPCs of the ASDRs in 204 countries and territories. SDI, sociodemographic index; ASDR, age-standardized death rate; EAPC, estimated annual percent change.

Figure 4

Distribution of DALYs due to Alzheimer's disease and other dementias in 204 countries and territories from 1990 to 2019 by age group and SDI region. (A) DALYs rate in each age group; (B) Correlations between the ASR of DALYs due to Alzheimer's disease and other dementias and SDI regions in 2019; associations were calculated with Pearson correlation analysis; (C) ASR of DALYs of 204 countries and territories; (D) EAPCs in the ASR of DALYs in 204 countries and territories. DALYs, disability-adjusted life-years; SDI, sociodemographic index; ASR, age-standardized rate; EAPC, estimated annual percent change.

Figure 5

Impact of risk factors on the disease burden of Alzheimer's disease by SDI region and gender, 2019. (A) Contribution of three risk factors for death and DALYs in different SDI regions; (B) Contribution of three risk factors to death and DALYs in both sexes. ASDR, age-standardized death rate; DALYs, disability-adjusted life-years; SDI, sociodemographic index.