BACKGROUND: Metabolic-associated fatty liver disease (MAFLD) is the predominant form of chronic liver disease worldwide. This study was designed to investigate the proportion and characteristics of MAFLD within the general Chinese population and to identify the contributory risk factors for liver fibrosis among MAFLD individuals. METHODS: The participants were recruited from a cohort undergoing routine health evaluations at the Third Hospital of Hebei Medical University between May 2019 and March 2023. The diagnosis of MAFLD was based on the established clinical practice guidelines. The fibrosis-4 index score (FIB-4) was employed to evaluate hepatic fibrosis, with a FIB-4 score of ≥1.3 indicating significant fibrosis. Binary logistic regression analyses were used to determine risk factors associated with significant hepatic fibrosis in MAFLD. RESULTS: A total of 22,970 participants who underwent comprehensive medical examinations were included in the analysis. The overall proportion of MAFLD was 28.77% (6608/22,970), with 16.87% (1115/6608) of these patients showing significant fibrosis as assessed using FIB-4. Independent risk factors for significant liver fibrosis in MAFLD patients were male (odds ratio [OR] = 0.676, 95% confidence interval [CI]: 0.558-0.821), hepatitis B surface antigen (HBsAg) positivity (OR = 2.611, 95% CI: 1.557-4.379), body mass index ≥23.00 kg/m 2 (OR = 0.632, 95% CI: 0.470-0.851), blood pressure ≥130/85 mmHg (OR = 1.885, 95% CI: 1.564-2.272), and plasma glucose ≥5.6 mmol/L (OR = 1.815, 95% CI: 1.507-2.186) (all P <0.001). CONCLUSIONS The proportion of MAFLD in an urban Chinese population is 28.77%. About 16.87% of MAFLD patients presented with significant liver fibrosis. Independent risk factors for significant liver fibrosis in MAFLD patients should be noticed.
Humans ; Male ; Female ; Liver Cirrhosis/pathology* ; Middle Aged ; Risk Factors ; Adult ; Fatty Liver/pathology* ; Aged ; China/epidemiology* ; Logistic Models ; Urban Population ; East Asian People

BACKGROUND: Metabolic-associated fatty liver disease (MAFLD) is a common liver disease and may become the leading cause of severe liver disease in the future. The Global Burden of Disease (GBD) study assesses MAFLD's impact in countries and regions worldwide, providing insights into its prevalence. METHODS: Prevalence data for MAFLD from 1990 to 2021 by country and region in all sex and age groups were collected from the Global Health Data Exchange. The categorization of countries and geographic areas by development was performed using the Sociodemographic Index (SDI). RESULTS: Between 1990 and 2021, the global crude prevalence rate of MAFLD increased from 10.6% to 16.1% (beta-coefficient: 0.2%, 95% confidence interval [CI]: 0.2-0.2%, P  <0.001), and the age-standardized prevalence rate was increased from 12.1% to 15.0% (beta-coefficient: 0.1%, 95% CI: 0.1-0.1%, P  <0.001). In 2021, MAFLD was estimated to have affected 1.3 billion people worldwide. Significant uptrends were observed in all regions, super regions, and SDI categories. The fastest increase from 1990 to 2021 and the highest prevalence rate in 2021 were experienced by countries and territories with high-middle and middle SDI. An increase in the prevalence of MAFLD from 1990 to 2021 was demonstrated in all but six countries. CONCLUSIONS In 2021, the number of patients affected by MAFLD was doubled compared to 1990, and the prevalence rate increased by over 50%. The burden of MAFLD, as measured by prevalence, was more prominent in countries and territories with middle SDI and in those located in North African and Middle Eastern, possibly due to changes in lifestyle in these areas over the past 30 years.
Humans ; Global Burden of Disease ; Prevalence ; Male ; Female ; Middle Aged ; Adult ; Global Health ; Fatty Liver/epidemiology* ; Aged

BACKGROUND: Chronic liver disease (CLD), mainly non-alcoholic fatty liver disease (NAFLD), is a significant public health concern worldwide. This study aims to quantify the burden of NAFLD in CLD globally and within China, using data from the Global Burden of Disease (GBD) Study 2021, providing crucial insights for global and local health policies. METHODS: The study used comprehensive data from the GBD study 2021. It included estimates of prevalence, incidence, mortality, and disability-adjusted life years (DALYs). Age-standardized rates and average annual percent change (AAPC) from 2011 to 2021 were reported. A meticulous decomposition analysis was conducted. RESULTS: In 2021, there were 1582.5 million prevalent cases, 47.6 million incident cases, 1.4 million deaths, and 44.4 million DALYs attributable to CLD, globally. Among these, NAFLD has emerged as the predominant cause, accounting for 78.0% of all prevalent CLD cases (1234.7 million) and 87.2% of incident cases (41.5 million). Correspondingly, NAFLD had the highest age-standardized prevalence (15,017.5 per 100,000 population) and incidence (876.5 per 100,000 population) rates among CLDs. In addition, China's CLD age-standardized prevalence rate was 21,659.5 per 100,000 population, and the age-standardized incidence rate was 752.6 per 100,000 population, higher than the global average. From 2011 to 2021, the global prevalence rate of CLD increased slowly (AAPC = 0.17), consistent with the trend in China (AAPC = 0.23). Furthermore, the prevalence rate of NAFLD rose significantly in China (AAPC = 1.30) compared with the global average (AAPC = 0.91). Decomposition analysis also showed the worldwide increase in deaths and DALYs for NAFLD, which were primarily attributable to population growth and aging. CONCLUSIONS The burden of CLD and NAFLD remains substantial globally and within China in terms of high prevalence and incidence. As such, this underscores the need for targeted prevention and treatment strategies. These findings emphasize the importance of continued surveillance and research to mitigate the growing impact of liver diseases on global and Chinese health systems.
Humans ; Non-alcoholic Fatty Liver Disease/mortality* ; Global Burden of Disease ; China/epidemiology* ; Prevalence ; Male ; Disability-Adjusted Life Years ; Female ; Incidence ; Middle Aged ; Chronic Disease ; Adult ; Quality-Adjusted Life Years ; Liver Diseases/epidemiology* ; Aged

OBJECTIVES: To systematically evaluate the prevalence and risk factors of non-alcoholic fatty liver disease (NAFLD) in overweight and obese children and adolescents in China. METHODS: Databases including China National Knowledge Infrastructure, Wanfang Data, VIP Database, China Biomedical Literature Database, PubMed, Embase, Web of Science, and Cochrane Library were searched, from database inception to October 2024. Two researchers independently screened the literature, extracted data, and assessed the quality of the studies according to inclusion and exclusion criteria. A Meta analysis was conducted using Stata 16.0 software. RESULTS: A total of 42 studies involving 16 481 overweight and obese children and adolescents were included. The Meta analysis results showed that the prevalence of NAFLD among overweight and obese children in China was 43% (95%CI: 37%-48%). Factors associated with NAFLD included being male (OR=1.61, 95%CI: 1.17-2.04), increased weight (MD=10.33, 95%CI: 9.08-11.57), increased waist circumference (MD=5.49, 95%CI: 3.36-7.62), longer duration of obesity (MD=0.31, 95%CI: 0.02-0.61), higher body mass index (MD=3.11, 95%CI: 2.07-4.16), elevated fasting blood glucose levels (MD=0.17, 95%CI: 0.06-0.29), higher triglyceride levels (MD=0.32, 95%CI: 0.17-0.47), elevated total cholesterol levels (MD=0.15, 95%CI: 0.10-0.21), higher low-density lipoprotein cholesterol levels (MD=0.14, 95%CI: 0.04-0.23), increased alanine aminotransferase levels (MD=24.39, 95%CI: 18.57-30.20), increased aspartate aminotransferase levels (MD=12.49, 95%CI: 9.67-15.32), elevated serum insulin levels (MD=4.47, 95%CI: 2.57-6.36), higher homeostasis model assessment-insulin resistance (MD=0.45, 95%CI: 0.30-0.59), and elevated uric acid levels (MD=55.91, 95%CI: 35.49-76.32) (P<0.05). CONCLUSIONS The prevalence of NAFLD among overweight and obese children and adolescents in China is high. Male gender, increased weight, increased waist circumference, prolonged obesity duration, higher body mass index, dyslipidemia, and elevated levels of fasting blood glucose, liver enzymes, serum insulin, homeostasis model assessment-insulin resistance, and uric acid are potential risk factors for NAFLD in this population.
Humans ; Non-alcoholic Fatty Liver Disease/etiology* ; Risk Factors ; Adolescent ; Child ; Overweight/complications* ; Prevalence ; China/epidemiology* ; Obesity/complications* ; Male ; Female

BACKGROUND: Many factors are associated with the development and progression of liver fat and fibrosis; however, genetics and the gut microbiota are representative factors. Moreover, recent studies have indicated a link between host genes and the gut microbiota. This study investigated the effect of patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 (C > G), which has been reported to be most involved in the onset and progression of fatty liver, on liver fat and fibrosis in a cohort study related to gut microbiota in a non-fatty liver population. METHODS: This cohort study included 214 participants from the health check-up project in 2018 and 2022 who had non-fatty liver with controlled attenuation parameter (CAP) values <248 dB/m by FibroScan and were non-drinkers. Changes in CAP values and liver stiffness measurement (LSM), liver-related items, and gut microbiota from 2018 to 2022 were investigated separately for PNPLA3 rs738409 CC, CG, and GG genotypes. RESULTS: Baseline values showed no difference among the PNPLA3 rs738409 genotypes for any of the measurement items. From 2018 to 2022, the PNPLA3 rs738409 CG and GG genotype groups showed a significant increase in CAP and body mass index; no significant change was observed in the CC genotype group. LSM increased in all genotypes, but the rate of increase was highest in the GG genotype, followed by the CG and CC genotypes. Fasting blood glucose levels increased in all genotypes; however, HOMA-IR (Homeostasis Model Assessment of Insulin Resistance) increased significantly only in the GG genotype. HDL (high-density lipoprotein) and LDL (low-density lipoprotein) cholesterol levels significantly increased in all genotypes, whereas triglycerides did not show any significant changes in any genotype. As for the gut microbiota, the relative abundance of Feacalibacterium in the PNPLA3 rs738409 GG genotype decreased by 2% over 4 years, more than 2-fold compared to CC and GG genotypes. Blautia increased significantly in the CC group. CONCLUSION The results suggest that PNPLA3 G-allele carriers of non-fatty liver develop liver fat and fibrosis due to not only obesity and insulin resistance but also the deterioration of gut microbiota, which may require a relatively long course of time, even years.
Humans ; Gastrointestinal Microbiome ; Male ; Female ; Membrane Proteins/metabolism* ; Lipase/genetics* ; Middle Aged ; Liver Cirrhosis/epidemiology* ; Cohort Studies ; Genotype ; Adult ; Non-alcoholic Fatty Liver Disease/microbiology* ; Polymorphism, Single Nucleotide ; Acyltransferases ; Phospholipases A2, Calcium-Independent

BACKGROUND: Mitochondria, which harbor their own genome (mtDNA), have attracted attention due to the potential of mtDNA copy number (mtDNA-CN) as an indicator of mitochondrial dysfunction. Although mtDNA-CN has been proposed as a simple and accessible biomarker for metabolic disorders such as metabolic dysfunction-associated steatotic liver disease, the underlying mechanisms and the causal relationship remain insufficiently elucidated. In this investigation, we combined longitudinal epidemiological data, animal studies, and in vitro assays to elucidate the potential causal relationship between reduced mtDNA-CN and the development of steatotic liver disease (SLD). METHODS: We conducted a longitudinal study using data from a health examination cohort initiated in 1981 in Yakumo, Hokkaido, Japan. Data from examinations performed in 2015 and 2022 were analyzed, focusing on 76 subjects without SLD at baseline (2015) to assess the association between baseline mtDNA-CN and subsequent risk of SLD development. In addition, 28-day-old SD rats were fed ad libitum on a 45% high-fat diet and dissected at 2 and 8 weeks of age. Blood and liver mtDNA-CN were measured and compared at each feeding period. Additionally, in vitro experiments were performed using HepG2 cells treated with mitochondrial function inhibitors to induce mtDNA-CN depletion and to examine its impact on intracellular lipid accumulation. RESULTS: Epidemiological analysis showed that the subjects with low mtDNA-CN had a significantly higher odds ratio for developing SLD compared to high (odds ratio [95% confidence interval]: 4.93 [1.08-22.50]). Analysis of the animal model showed that 8 weeks of high-fat diet led to the development of fatty liver and a significant decrease in mtDNA-CN. A further 2 weeks of high-fat diet consumption resulted in a significant decrease in hepatic mtDNA-CN, despite the absence of fatty liver development, and a similar trend was observed for blood. Complementary in vitro experiments revealed that pharmacologically induced mitochondrial dysfunction led to a significant reduction in mtDNA-CN and was associated with increases in intracellular lipid accumulation in HepG2 cells. CONCLUSIONS Our findings suggest that reduced mtDNA-CN may contribute causally to SLD development and could serve as a convenient, noninvasive biomarker for early detection and risk assessment.
Animals ; DNA, Mitochondrial/genetics* ; Humans ; Male ; DNA Copy Number Variations ; Female ; Fatty Liver/blood* ; Rats ; Middle Aged ; Longitudinal Studies ; Rats, Sprague-Dawley ; Adult ; Japan/epidemiology* ; Aged ; Biomarkers/blood* ; Hep G2 Cells ; Diet, High-Fat/adverse effects*

OBJECTIVES: Non-alcoholic fatty liver disease (NAFLD) and hypertension are common metabolic disorders, both closely associated with insulin resistance (IR), suggesting potential shared pathological mechanisms. This study aims to investigate the mediating role of IR in the relationship between hypertension and NAFLD, and to evaluate the applicability and modeling value of various IR surrogate indices in predicting NAFLD risk. METHODS: A total of 280 976 individuals who underwent health examinations at the Health Management Center of the Third Xiangya Hospital of Central South University between August 2017 and December 2021 were included. NAFLD was diagnosed based on abdominal ultrasound findings, and hypertension was defined according to the criteria of the Chinese Guidelines for the Management of Hypertension. Demographic information, anthropometric indices, and biochemical parameters were collected, and multiple IR surrogate indices were constructed, including the triglyceride-glucose index (TyG) and its derivatives, as well as the metabolic score for insulin resistance (METS-IR). Group comparisons were performed between hypertensive and non-hypertensive participants, as well as between NAFLD and non-NAFLD participants. Pearson correlation analysis was applied to assess the associations of metabolic parameters and IR indices with NAFLD. Furthermore, mediation models were constructed to explore the mediating role of IR in the "hypertension-NAFLD" relationship. Finally, parametric models and machine learning algorithms were compared to evaluate their predictive performance and value in assessing NAFLD risk in this population. RESULTS: The prevalence of NAFLD was significantly higher in hypertensive individuals than in non-hypertensive participants (63.61% vs 33.79%, P<0.001), accompanied by elevated IR levels and adverse metabolic features. Correlation analysis and variable importance rankings across multiple models consistently identified TyG-waist circumference (TyG-WC) and METS-IR as the IR indices most strongly associated with NAFLD. In mediation analysis, the TyG-WC pathway explained 32.03% of the total effect, and the METS-IR pathway explained 17.02%. Interaction analysis showed that hypertension status may attenuate the mediating effect of IR (all interaction estimates were negative). In prediction model comparisons, the simplified model incorporating sex, age, WC, TyG-WC, and METS-IR demonstrated good performance in the test set. Logistic regression and its regularized form (LASSO regression) achieved an accuracy of 0.83, receiver operating characteristic (ROC)-area under the curve (AUC) of 0.91, and a Brier score of 0.12, comparable to ensemble models (random forest and XGBoost), with consistently stable performance across different algorithms. CONCLUSIONS IR plays a significant mediating role in the association between hypertension and NAFLD, with TyG-WC identified as a key indicator showing strong mechanistic relevance and predictive value. Risk prediction models based on IR surrogate indices demonstrate advantages in simplicity and interpretability, providing empirical support for the early screening and individualized prevention of NAFLD in the general population.
Humans ; Non-alcoholic Fatty Liver Disease/complications* ; Insulin Resistance ; Hypertension/epidemiology* ; Male ; Female ; Middle Aged ; Risk Factors ; Adult ; Machine Learning ; Triglycerides/blood*

Objective To analyze the changing trends of the burden of non-alcoholic fatty liver disease(NAFLD)in China from 1990 to 2021 and provide a basis for formulating prevention and treatment strategies.Methods The standardized incidence rate,prevalence,mortality,and disability-adjusted life year(DALY)rate of NAFLD in China from 1990 to 2021 were extracted from the Global Burden of Disease Study 2021.The average annual percentage change of rate data was calculated by Joinpoint 4.2 and the age,period,and birth cohort effects of the prevalence and DALY rate were analyzed by the age-period-cohort model.Results Compared to 1990,the incidence rate and prevalence of NAFLD have been on the rise,while the mortality and DALY rate have been declining.The age effect curves of prevalence and DALY rate showed an upward trend followed by a downward trend for both males and females.With the period from 1992 to 1996 as the reference group,the period effect curve of prevalence showed a downward trend followed by an upward trend,being the lowest in the period from 2002 to 2006(RR=0.93).The period effect curve of DALY rate showed a downward trend from 1992 to 2011 and then tended to flatten out.With the period from 1972 to 1981 as the reference group,the birth cohort effect curve of prevalence showed a steady upward trend in the general population and both male and female populations.The birth cohort effect curve of DALY rate showed an overall upward trend followed by a downward trend,with the peak occurring in the birth cohort group between 1922 and 1931.The DALY rate of NAFLD caused by smoking and high fasting blood glucose has shown a downward trend since 2014,and fasting blood glucose gradually became the dominant factor as age increased.Conclusions From 1990 to 2021,NAFLD in China has shown a rising prevalence but a significantly declining DALY rate.This suggests that current prevention and control strategies are effective,and further efforts should be made to raise residents' health awareness in controlling the occurrence and development of NAFLD.
Humans ; Non-alcoholic Fatty Liver Disease/epidemiology* ; China/epidemiology* ; Prevalence ; Female ; Male ; Incidence ; Disability-Adjusted Life Years ; Middle Aged ; Adult

Objective: To investigate the association between physical exercise and non-alcoholic fatty liver disease (NAFLD) in people infected with HBV. Methods: The information about the 3 813 participants infected with HBV, including the prevalence of NAFLD, prevalence of physical exercise and other covariates, were collected from the National Science and Technology Major Project of China during 2016-2020. The logistic regression model was used to evaluate the association between physical exercise and NAFLD in HBV infected patients, and subgroup analysis was performed to identify the effect modifiers. Results: A total of 2 259 HBV infected participants were included in the final analysis and 454 (20.10%) had NAFLD. After adjusting for covariates, we found that moderate physical exercise was a protective factor for NAFLD (OR=0.66, 95%CI: 0.46-0.94). Subgroup analysis suggested that the protective effect of moderate physical exercise on NAFLD might be stronger in women (OR=0.61, 95%CI: 0.36-1.01), those <45 years old (OR=0.24, 95%CI: 0.06-0.80), those who had low education level (OR=0.16, 95%CI: 0.04-0.49), those who had low annual income (OR=0.39, 95%CI: 0.16-0.89 for <30 000 yuan RMB; OR=0.64, 95%CI: 0.40-1.00 for 30 000-80 000 yuan RMB), those who had hypertension (OR=0.45, 95%CI: 0.21-0.88), those with BMI ≥24.0 kg/m² (OR=0.66, 95%CI: 0.43-1.01), those who had more daily fruit or vegetable intake (OR=0.61, 95%CI: 0.38-0.97), those who had more daily meat intake (OR=0.49, 95%CI: 0.23-0.97), and those who had no smoking history (OR=0.66, 95%CI: 0.45-0.95) or passive smoking exposure (OR=0.61, 95%CI: 0.37-0.97). Conclusions: Among HBV infected patients, moderate physical exercise was negatively associated with the prevalence of NAFLD. Women, young people, those who had low education level, those who had low annual income, those with hypertension, those with high BMI, those who had more daily fruit or vegetable and meat intakes, and those who had no smoking history or passive smoking exposure might be more sensitive to the protective effect.
Humans ; Female ; Adolescent ; Middle Aged ; Non-alcoholic Fatty Liver Disease/epidemiology* ; Hepatitis B virus ; Risk Factors ; Tobacco Smoke Pollution ; Exercise ; Hypertension

Aged ; Humans ; Non-alcoholic Fatty Liver Disease/etiology* ; China/epidemiology*