Background

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide and the leading cause of liver-related morbidity and mortality. We aimed to predict the burden of NAFLD by examining and estimating the temporal trends of its worldwide prevalence and incidence.

Methods

In this systematic review and meta-analysis, we searched MEDLINE, EMBASE, Scopus, and Web of Science without language restrictions for reports published between date of database inception and May 25, 2021. We included observational cross-sectional or longitudinal studies done in study populations representative of the general adult population, in whom NAFLD was diagnosed using an imaging method in the absence of excessive alcohol consumption and viral hepatitis. Studies were excluded if conducted in paediatric populations (aged <18 years) or subgroups of the general population. Summary estimates were extracted from included reports by KR and independently verified by HA using the population, intervention, comparison, and outcomes framework. Primary outcomes were the prevalence and incidence of NAFLD. A random-effects meta-analysis was used to calculate overall and sex-specific pooled effect estimates and 95% CIs.

Findings

The search identified 28 557 records, of which 13 577 records were screened; 299 records were also identified via other methods. In total, 72 publications with a sample population of 1 030 160 individuals from 17 countries were included in the prevalence analysis, and 16 publications with a sample population of 381 765 individuals from five countries were included in the incidence analysis. The overall prevalence of NAFLD worldwide was estimated to be 32·4% (95% CI 29·9–34·9). Prevalence increased significantly over time, from 25·5% (20·1–31·0) in or before 2005 to 37·8% (32·4–43·3) in 2016 or later (p=0·013). Overall prevalence of NAFLD was significantly higher in men than in women (39·7% [36·6–42·8] vs 25·6% [22·3–28·8]; p<0·0001). The overall incidence of NAFLD was estimated to be 46·9 cases per 1000 person-years (36·4–57·5); 70·8 cases per 1000 person-years (48·7–92·8) in men and 29·6 cases per 1000 person-years (20·2–38·9) in women (p<0·0001). There was considerable heterogeneity between studies of both NAFLD prevalence (I²=99·9%) and NAFLD incidence (I²=99·9%).

Interpretation

Worldwide prevalence of NAFLD is considerably higher than previously estimated and is continuing to increase at an alarming rate. Incidence and prevalence of NAFLD are significantly higher among men than among women. Greater awareness of NAFLD and the development of cost-effective risk stratification strategies are warranted to address the growing burden of NAFLD.

Funding

Canadian Institutes of Health.

中文翻译：

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全球 NAFLD 的患病率和发病率：系统评价和荟萃分析

背景

非酒精性脂肪性肝病 (NAFLD) 是全球最常见的肝脏疾病，也是肝脏相关发病率和死亡率的主要原因。我们旨在通过检查和估计其全球患病率和发病率的时间趋势来预测 NAFLD 的负担。

方法

在这项系统评价和荟萃分析中，我们在没有语言限制的情况下搜索了 MEDLINE、EMBASE、Scopus 和 Web of Science，以获取在数据库成立之日至 2021 年 5 月 25 日之间发表的报告。我们纳入了在研究中完成的观察性横断面或纵向研究代表一般成年人的人群，在没有过度饮酒和病毒性肝炎的情况下，使用影像学方法诊断出 NAFLD。如果在儿科人群（年龄 <18 岁）或一般人群的亚组中进行，则排除研究。概要估计值是从 KR 所包含的报告中提取的，并由 HA 使用人口、干预、比较和结果框架独立验证。主要结果是 NAFLD 的患病率和发病率。

发现

检索识别出 28 557 条记录，其中 13 577 条记录被筛选；还通过其他方法识别了 299 条记录。共有来自 17 个国家的 72 篇样本人口为 1 030 160 人的出版物被纳入患病率分析，来自五个国家的 16 篇样本人口为 381 765 人的样本被纳入发病率分析。全世界 NAFLD 的总体患病率估计为 32·4% (95% CI 29·9–34·9)。随着时间的推移，患病率显着增加，从 2005 年或之前的 25·5% (20·1–31·0) 到 2016 年或更晚的 37·8% (32·4–43·3) (p=0·013)。男性 NAFLD 的总体患病率显着高于女性（39·7% [36·6–42·8] vs25·6% [22·3–28·8]；p<0·0001)。NAFLD 的总发病率估计为每 1000 人年 46·9 例（36·4-57·5）；男性70·8例/1000人年（48·7-92·8），女性29·6例/1000人年（20·2-38·9）（p<0·0001）。NAFLD 患病率（ I ² =99·9%）和 NAFLD 发病率（I ² =99·9%）的研究之间存在相当大的异质性。

解释

NAFLD 的全球患病率远高于先前的估计，并以惊人的速度继续增加。男性 NAFLD 的发病率和患病率明显高于女性。有必要提高对 NAFLD 的认识并制定具有成本效益的风险分层策略，以解决 NAFLD 日益严重的负担。

资金

加拿大卫生研究院。