The Global, Regional, and National Burden and Trends of NAFLD in 204 Countries and Territories: An Analysis From Global Burden of Disease 2019

Abstract

Background: Nonalcoholic fatty liver disease (NAFLD) poses a substantial socioeconomic burden and is becoming the fastest growing driver of chronic liver disease, potentially accompanied by a poor prognosis.

Objective: We aim to elucidate the global and regional epidemiologic changes in NAFLD during the past 30 years and explore the interconnected diseases.

Methods: Data on NAFLD incidence, prevalence, death, and disability-adjusted life-years (DALYs) were extracted from the Global Burden of Disease Study 2019. The age-standardized incident rate (ASIR), age-standardized prevalent rate (ASPR), age-standardized death rate (ASDR), and age-standardized DALYs were calculated to eliminate the confounding effects of age when comparing the epidemiologic changes between different geographical regions. In addition, we also investigated the correlation between the NAFLD burden and the sociodemographic index (SDI). Finally, the associations of the 3 common comorbidities with NAFLD were determined.

Results: Globally, the incidence and prevalence of NAFLD both increased drastically during the past 3 decades (incidence: from 88,180 in 1990 to 172,330 in 2019, prevalence: from 561,370,000 in 1990 to 1,235,700,000 in 2019), mainly affecting young adults who were aged from 15 to 49 years. The ASIR increased slightly from 1.94 per 100,000 population in 1990 to 2.08 per 100,000 population in 2019, while ASPR increased from 12,070 per 100,000 population in 1990 to 15,020 per 100,000 population in 2019. In addition, the number of deaths and DALYs attributable to NAFLD increased significantly as well from 93,760 in 1990 to 168,970 in 2019 and from 2,711,270 in 1990 to 4,417,280 in 2019, respectively. However, the ASDR and age-standardized DALYs presented decreasing trends with values of estimated annual percentage change equaling to -0.67 and -0.82, respectively (ASDR: from 2.39 per 100,000 population in 1990 to 2.09 per 100,000 population in 2019; age-standardized DALYs: from 63.28 per 100,000 population in 1990 to 53.33 per 100,000 population in 2019). Thereinto, the burden of death and DALYs dominated the patients with NAFLD who are older than 50 years. Moreover, SDI appeared to have obvious negative associations with ASPR, ASDR, and age-standardized DALYs among 21 regions and 204 countries, although there is no marked association with ASIR. Finally, we found that the incidence and prevalence of NAFLD were positively related to those of diabetes mellitus type 2, stroke, and ischemic heart disease.

Conclusions: NAFLD is leading to increasingly serious health challenges worldwide. The morbidity presented a clear shift toward the young populations, while the heavier burden of death and DALYs in NAFLD was observed in the aged populations and in regions with relatively low SDI. Comprehensive acquisition of the epidemiologic pattern for NAFLD and the identification of high-risk comorbidities may help policy makers and clinical physicians develop cost-effective prevention and control strategies, especially in countries with a high NAFLD burden.

Keywords: Global Burden of Disease Study 2019; diabetes mellitus type 2; disability-adjusted life-years; epidemiologic change; incidence; ischemic heart disease; mortality; non-alcoholic fatty liver disease; prevalence; stroke.

Figure 1

The trends of changes in NAFLD incidence, prevalence, deaths, and DALY from 1990 to 2019. The trends of changes in (A) incidences, (B) prevalence, (C) deaths, and (D) DALY (D) are shown. Blue bars represent males, and red bars represent females. DALYs: disability-adjusted life years; NAFLD: nonalcoholic fatty liver disease; SDI: sociodemographic index.

Figure 2

The age-standardized rates of NAFLD in 2019 and EAPC of NAFLD ASRs from 1990 to 2019 in 204 countries and territories. The (A) ASIR, (B) ASPR, (C) ASDR, and (D) age-standardized DALY of NAFLD around the world in 2019 are shown. The EAPC of (E) ASIR, (F) ASPR, (G) ASDR, and (H) age-standardized DALY in the past 30 years are shown. ASDR: age-standardized death rate; ASIR: age-standardized incident rate; ASPR: age-standardized prevalent rate; ASRs: age-standardized rates; DALY: disability-adjusted life years; EAPC: estimated annual percentage change; NAFLD: nonalcoholic fatty liver disease.

Figure 3

Correlation analyses between ASRs of NAFLD and SDI in 21 regions and 204 territories from 1990 to 2019. The SDI presented no obvious correlation with the (A, E) ASIR and negative correlations with (B, F) ASPR, (C, G) ASDR, and (D, H) age-standardized DALY in 21 regions and 204 territories. ASDR: age-standardized death rate; ASIR: age-standardized incident rate; ASPR: age-standardized prevalent rate; ASR: age-standardized rate; DALY: disability-adjusted life years; NAFLD: nonalcoholic fatty liver disease; SDI: sociodemographic index.

Figure 4

The trends of changes in NAFLD incidence, prevalence, deaths, and DALYs from 1990 to 2019 in different age groups. The trends of changes in (A) incidence, (B) prevalence, (C) deaths, and (D) DALYs. DALY: disability-adjusted life years; NAFLD: nonalcoholic fatty liver disease; SDI: sociodemographic index.

Figure 5

The associations of incidence and prevalence between NAFLD and other comorbidities in 21 regions and 204 territories from 1990 to 2019. NAFLD presented strongly positive correlations of incidence/prevalence with (A, D, G, J) DM2, (B, E, H, K) stroke, and (C, F, I, L) IHD in 21 regions and 204 territories from 1990 to 2019. DM2: diabetes mellitus type 2; IHD: ischemic heart disease; NAFLD: nonalcoholic fatty liver disease.