Temporal trend and attributable risk factors of Alzheimer's disease and other dementias burden in China: Findings from the Global Burden of Disease Study 2021

Abstract

Introduction: We examined the burden of Alzheimer's disease and other dementias (ADOD) and attributable factors at the national and provincial levels in China.

Methods: Using the Global Burden of Diseases Study 2021, we estimated incidence, prevalence, mortality rate, disability-adjusted life years (DALYs), and the ratio of years lived with disability (YLD) to DALYs for ADOD in China. Estimated annual percentage changes (EAPCs) were used to quantify the temporal trends from 1990 to 2021.

Results: In 2021, China experienced the highest ADOD burden among Group of 20 member nations. The EAPCs for age-standardized rates for incidence, age-standardized rates for prevalence, and age-standardized mortality rate were 0.41 (uncertainty intervals [UIs] 0.34-0.49); 0.44 (UI: 0.36-0.52); and -0.19 (UI: -0.23 to -0.15), respectively. Between 1990 and 2021, the number of people with ADOD increased by 322.18% and DALYs associated with ADOD increased by 272.71%; most of these increases were explained by population aging.

Discussion: Considering the aging Chinese population, targeted strategies to prevent dementia are urgently needed.

Highlights: China experienced the highest dementia burden among Group of 20 member nations. High body mass index, high fasting plasma glucose, and smoking were major risk factors for Alzheimer's disease and other dementias (ADOD) burden. Since 1990, the incidence and prevalence of ADOD increased substantially in China. The mortality rate related to ADOD decreased consistently. Considering the aging Chinese population, targeted strategies are urgently needed.

Keywords: Alzheimer's disease and other dementias; Global Burden of Diseases Study; disability‐adjusted life years; incidence; mortality; prevalence.

FIGURE 1

Trend of age‐standardized incidence, prevalence, mortality rates, DALYs, YLL, and YLD for ADOD by sex in China from 1990 to 2021. ADOD, Alzheimer's disease and other dementias; DALYs, disability‐adjusted life years; YLD, years lived with disability; YLL, years of life lost.

FIGURE 2

Crude incidence, prevalence, mortality rates, and DALYs of ADOD in China in 2021 and a map of Chinese population density. A, Crude incidence. B, Crude prevalence. C, Crude mortality rate. D, Crude DALYs. E, Population density. F, The proportion of people aged ≥ 65 years in 2021. The darker the color on the map, the higher the burden index value of the province. ADOD, Alzheimer's disease and other dementias; DALYs, disability‐adjusted life years.

FIGURE 3

Trends and distributions for the ratio of YLD to DALYs for ADOD in China, the G20, and the world from 1990 to 2021. A, Ratio of YLD to DALY in China, the G20, and the world from 1990 to 2021. B, Distribution of the ratio of YLD to DALYs in China in 2021. C, DALYs and ratio of YLD to DALY for ADOD in different provinces of China in 2021. The abscissa is the ratio of YLD to DALYs; the ordinate is the DALYs per 100,000 population for the indicated provinces; and the dotted lines are taken from the third quartile of the data. The plot is divided into nine groups as indicated. ADOD, Alzheimer's disease and other dementias; DALYs, disability‐adjusted life years; G20, Group of 20; YLD, years lived with disability.

FIGURE 4

Decomposition analysis of DALYs and mortality rate changes for ADOD in China in 2021. A, DALY changes. B, Mortality rate changes. Attributable risk factors of ADOD burden in China: population aging, population growth, high BMI, high fasting plasma glucose, smoking, and unknown risk factors. If the contribution of a risk factor is negative, the histogram of the indicator is to the left of the reference abscissa, which, in this figure, is 0. ADOD, Alzheimer's disease and other dementias; BMI, body mass index; DALYs, disability‐adjusted life years.