Comprehensive epidemiological study on the actual condition and natural history of non-alcoholic fatty liver disease

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H03886
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 58020:Hygiene and public health-related: including laboratory approach
• Research Institution: Hiroshima University
• Principal Investigator: Tanaka Junko 広島大学, 医系科学研究科(医), 教授 (70155266)
• Co-Investigator(Kenkyū-buntansha): 杉山 文 広島大学, 医系科学研究科(医), 助教 (50778280) ; 秋田 智之 広島大学, 医系科学研究科(医), 講師 (80609925) ; 大久 真幸 広島大学, 医系科学研究科(医), 助教 (20727250)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 非アルコール性脂肪性肝疾患 / NAFLD / NASH / 大規模コホート研究 / 自然史 / 数理疫学的モデル

Outline of Final Research Achievements

This study aimed to understand the epidemiology and natural history of NAFLD by analyzing a database of 75,670 individuals with data on alcohol consumption and ultrasonography results from a large-scale health screening data (2008-2019). The results revealed the following findings: 1) There were no significant differences in the prevalence and incidence of fatty liver among different categories of alcohol consumption. 2) The distribution of a scoring system for liver fibrosis, FIB4-index, in the general population was greatly influenced by age factors. 3) By utilizing a Markov model to predict the progression of liver diseases, it was estimated that the cumulative incidence of fatty liver by the age of 70, starting from a normal liver at the age of 40, was approximately 30% for both men and women, while the cumulative incidence of NASH was around 1%. Therefore, it was considered imperative to improve lifestyle habits among middle-aged individuals to reduce future disease burden.

Free Research Field

疫学、疾病制御、肝炎ウイルスの疫学

Academic Significance and Societal Importance of the Research Achievements

本研究は、大規模一般集団のデータ解析により、飲酒は脂肪肝有病・罹患頻度に有意に関連せず、肥満が最も影響が大きい独立した因子であることを示した。近年飲酒量や他の肝疾患の有無は問わない包括的な疾患概念・定義として提唱されているMetabolic dysfunction-associated fatty liver Disease （MAFLD）はより実態に合っていると考えられた。また、FIB4-indexは簡便性という利点はあるものの、一般集団に対する一次スクリーニングとしての肝線維化評価には適さない可能性を指摘した。数理疫学モデルにより、一般集団における脂肪性肝疾患の病態推移予測を明らかにした。