AASLD China Voice | Professor Wei Lai’s Team at Tsinghua Chang Gung: Latest Developments in the Nationwide “MAFLD Epidemiological Survey Research Project” on Health Check-up Populations
Editor’s Note:
In 2020, the international expert consensus on metabolic dysfunction-associated fatty liver disease (MAFLD) proposed a new definition, suggesting MAFLD as a more appropriate term to describe liver diseases related to metabolic dysfunction. According to the latest standards, patients with liver fat deposition meet at least one of the following three criteria: overweight or obesity, type 2 diabetes, or the presence of metabolic dysfunction (if their weight is normal).
To comprehensively understand the current status of MAFLD in China, promote awareness among medical professionals and patients, and increase the diagnosis rate of the disease, in 2022, the National Health Examination Population “MAFLD Epidemiological Survey Research Project,” led by Professor Wei Lai of Tsinghua University Affiliated Beijing Tsinghua Chang Gung Hospital and co-initiated by the China Liver Health Promotion Center, was successfully launched. The two latest research findings from the project have been included in the 2023 Annual Meeting of the American Association for the Study of Liver Disease (AASLD). Professor Wei Lai has been invited by the International Liver Disease Journal to provide a detailed introduction to these two studies, the content of which is shared below.
Study One
Prevalence and Clinical Characteristics of MAFLD in Chinese Adults
We recruited 2019 adult participants from 31 health examination centers in 11 cities across China for a detailed survey and collected laboratory test results. In addition to routine health check items, we provided participants with free tests for glycated hemoglobin A1c (HbA1c), fasting plasma insulin, hypersensitivity C-reactive protein (hsCRP), and transient elastography (TE) to comprehensively assess metabolic spectrum and liver fibrosis. Liver fat deposition was defined as a controlled attenuation parameter (CAP) value ≥244 dB/m.
The results showed that the prevalence of MAFLD and non-alcoholic fatty liver disease (NAFLD) in the healthy examination cohort was 45.8% and 42.6%, respectively (P=0.43). Among participants with a body mass index (BMI) <23, 23–24.9, and ≥25 kg/m2, the prevalence of MAFLD was 9.25%, 43.95%, and 77.88%, respectively. Correspondingly, the prevalence of NAFLD was 16.30%, 39.53%, and 66.47% (Figure 1). Among MAFLD participants, the proportions of the overweight/obese subgroup, normal weight with metabolic abnormalities subgroup, and type 2 diabetes subgroup were 92.8%, 6.9%, and 13.4%, respectively. The average age of MAFLD participants was 45.8 years, with 65.9% being male. MAFLD participants had similar BMI, waist circumference, high-density lipoprotein cholesterol, triglycerides, FIB-4 index, NAFLD fibrosis score, and liver stiffness values compared to NAFLD participants
.These results suggest that MAFLD is highly prevalent in the health examination population in China, and the definition of MAFLD does not improve the identification of high-risk patients for liver fibrosis.
Study Two
MAFLD Excludes Lean Fatty Liver Patients with Similar Metabolic Profiles and Liver Fibrosis Levels in Healthy Lean Subjects
Currently, there is limited data on the prevalence and clinical characteristics of MAFLD in lean individuals. Our objective was to investigate the clinical characteristics of lean MAFLD and the impact of the MAFLD definition on the prevalence of fatty liver in lean individuals. Lean MAFLD was defined as MAFLD participants with a BMI <23 kg/m2 and two or more metabolic risk factors. Previous studies on lean MAFLD often lacked indicators such as HbA1c, homeostatic model assessment of insulin resistance (HOMA-IR), and hsCRP, leading to inaccurate diagnoses. Our study comprehensively assessed these metabolic risk factors.
The results showed that the prevalence of lean MAFLD in the overall population and the MAFLD population was 3.3% and 7.2%, respectively. Compared to non-lean MAFLD, lean MAFLD was older, more likely to be female, with lower proportions of metabolic syndrome, waist circumference, diastolic blood pressure, liver enzymes, HOMA-IR, APRI, NAFLD fibrosis score, liver stiffness values, and CAP values. However, high-density lipoprotein cholesterol was higher. In the lean population, the prevalence of MAFLD was lower than that of NAFLD (9.25% vs. 16.30%, P<0.05). Among the 128 lean individuals with liver fat deposition, 59 met the diagnosis criteria for both lean MAFLD and NAFLD (lean MAFLD+ and NAFLD+), 59 only met the diagnosis criteria for lean NAFLD (lean MAFLD- but NAFLD+), and 8 only met the diagnosis criteria for lean MAFLD (lean MAFLD+ but NAFLD-). Lean MAFLD- but NAFLD+ had metabolic dysfunction and liver fibrosis levels comparable to healthy lean subjects.
These results suggest that the definition of MAFLD reduces the prevalence of fatty liver in the lean population but excludes lean fatty liver patients with similar metabolic profiles and liver fibrosis levels as healthy lean subjects.
Reference:
[1] Yang M, Liu H, Guo S, et al. The prevalence and clinical characteristics of Chinese adults with metabolic dysfunction-associated fatty liver disease. AASLD 2023. Poster 2260-C.
[2] Yang M, Liu H, Guo S, et al. MAFLD excludes lean fatty liver disease patients with similar metabolic profiles and hepatic fibrosis compared to lean healthy subjects. AASLD 2023. Poster 2216-A.
