Prevalence of non-alcoholic fatty liver disease and its association with lifestyle habits in adults in Chile: a cross-sectional study from the National Health Survey 2016-2017

Effect of Intermittent Fasting on Lipid Profile, Anthropometric and Hepatic Markers in Non-Alcoholic Fatty Liver Disease (NAFLD): A Systematic Review

BACKGROUND

The first-line treatment for non-alcoholic fatty liver disease (NAFLD) is lifestyle modification; this should accompany any pharmacological intervention. Intermittent fasting (IF) has shown benefits over metabolic and cardiovascular parameters. Non-religious IF includes Time-Restricted Feeding (TRF), Alternate-Day Fasting (ADF), and 5:2 IF interventions.

OBJECTIVE

To evaluate the effects of IF on anthropometric, liver damage, and lipid profile markers in subjects with NAFLD.

METHODS

A bibliographic search was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using PubMed and Scopus databases.

RESULTS

Five studies involving 470 patients with NAFLD were included. In relation to anthropometric markers, all the articles reported body weight reduction (2.48-7.63%), but only ADF and 5:2 IF reported a body weight reduction >5%; also, all the articles reported fat mass reduction. Concerning hepatic markers, all the articles reported a reduction in hepatic steatosis and alanine aminotransferase activity, but no changes in fat-free mass and high-density lipoprotein cholesterol levels. There were variable results on fibrosis, other liver enzymes, waist circumference and body mass index, as well as the levels of triglycerides, total cholesterol, and low-density lipoprotein cholesterol.

CONCLUSION

Any form of IF could be potentially beneficial for NAFLD treatment and some associated cardiometabolic parameters. However, it is necessary to evaluate the effects and safety of IF in long-term studies involving a higher number of participants with different stages of NAFLD. The effect of IF on NAFLD-associated vascular risk also needs evaluation.

Impact of smoking cessation on non-alcoholic fatty liver disease prevalence: a systematic review and meta-analysis

OBJECTIVES

The negative effects of smoking on numerous cardiovascular and metabolic diseases have been widely acknowledged. However, the potential effect of smoking cessation is relatively unelucidated. The objective of this study is to explore whether the prevalence of non-alcoholic fatty liver disease (NAFLD) in former smokers differs from the prevalence in current smokers.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Four databases, that is, PubMed, Web of Science, Journal@Ovid and Scopus were searched from inception to 31 January 2023.

ELIGIBILITY CRITERIA

Population-based cross-sectional studies, including the baseline data of cohort studies with identified NAFLD diagnostic methods, and smoking status (current smoker or former smoker) of participants were included.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted the data including cigarette smoking status, country/region of studies, NAFLD diagnostic methods, sex, the average age and body mass index (BMI) of NAFLD participants and assessed the risk of bias with Agency for Healthcare Research and Quality (AHRQ) methodology checklist. Risk ratio (RR) of NAFLD prevalence in former smokers was pooled using the random-effects model.

RESULTS

28 studies involving 4 465 862 participants were included. Compared with current smokers, the RR of overall NAFLD prevalence in former smokers was 1.13 (95% CI: 1.08 to 1.19, prediction interval: 0.92-1.39). This result persisted after adjustment for diagnostic methods, country/region, sex, age and BMI. Sensitivity analysis and risk of bias assessment indicated a stable conclusion.

CONCLUSIONS

NAFLD prevalence in former smokers was at least not lower than that in current smokers and was partially related to increased BMI after smoking cessation, indicating that smoking cessation was possibly not a protective factor against NAFLD. Although the meta-analysis based on cross-sectional studies cannot conclude the causal relationships between smoking cessation and NAFLD onset, the potential onset of NAFLD associated with smoking cessation should be highlighted.

PROSPERO REGISTRATION NUMBER

CRD42023394944.

Unraveling the Connection between Fatty Liver Severity with Gender, Lifestyle, and Health Risks among Workers

The purpose of this study was to investigate the correlation between the severity of fatty liver and factors such as gender, lifestyle, and the risks of metabolic abnormalities, inflammation, and liver dysfunction in the working population. This cross-sectional study included 2936 workers aged 21-64 years. The severity of fatty liver was assessed using ultrasound. A self-administered survey was used to evaluate lifestyle habits. Data on anthropometric measurements, blood pressure, blood tests, and biochemical evaluations was collected. The 45.5% of workers had fatty liver. Males had a higher prevalence of fatty liver and health risks and several unhealthy lifestyle habits compared to females. The health behavior score related to exercise showed notable declines as the severity of fatty liver increased (p < 0.001). Percentages of current alcohol drinkers differed among different levels of fatty liver, with rates of 43.1, 48.4, 44.8, and 63.4% (p = 0.005) observed in the absence, mild, moderate, and severe fatty liver, respectively. Workers with fatty liver showed increased risks related to metabolic anomalies, especially in severe cases. The risk of inflammation and liver dysfunction also significantly increased with elevated fatty liver severity. Overall, fatty liver presents significant health risks, with nearly half of the workers diagnosed with the condition. To improve liver health, it is crucial to have customized strategies for promoting health, taking into account the different levels of severity in fatty liver.