Risk factors and protective factors for alcohol-related liver disease: A systematic review and meta-analysis

Background Although alcohol-related liver disease (ALD) is a global health threat, there are no specific effective treatments for it. Thus, efforts at preventing ALD are important and could be enhanced by using strategies based on validated risk and protective factors for the disease. Methods The literature on factors influencing the risk for ALD was systematically searched from PubMed, Embase, and the Cochrane library databases from inception to June 2022. Factors suitable for quantitative analysis were submitted to meta-analysis using fixed-effects and random-effects models to calculate each factor's risk ratio (RR) and 95% confidence interval (CI). Results Ten cohort studies (covering 1,005,339 subjects) that reported a clear causal relationship were included in the analysis, involving 11 potential risk factors (sex, race, education level, body mass index, alcohol consumption, types of alcoholic beverage, duration of drinking, drinking frequency, smoking, coffee consumption, and tea consumption). Three of these factors (sex, alcohol consumption, and smoking) were subjected to meta-analysis, and the results showed that male sex (RR = 2.84, 95% CI = 1.86-4.36), alcohol consumption >= 280 g/week (RR = 4.96, 95% CI = 2.71-9.07), and smoking (RR = 2.39, 95% CI = 1.97-2.89) were risk factors for ALD. Conclusions Many factors are likely to influence the incidence of ALD, and male sex, heavy alcohol consumption, and smoking increase the risk of ALD. The relationship between other factors and ALD risk needs further evaluation.