Risk Factors Related to the Development of Nonalcoholic Fatty Liver: A Systematic Review

Background: Nonalcoholic fatty liver disease (NAFLD) has a major impact on public health owing to its high morbidity and mortality due to its close relationship with several conditions, including metabolic syndrome, cirrhosis, and cancer. Therefore, this review aimed to systematically compile and summarize the scientific literature on early risk factors for NAFLD development. Methods: A systematic review of population-based cohort studies was conducted. Studies reporting the risk factors associated with nonalcoholic steatohepatitis (NASH) and NAFLD were screened. Results: The search yielded 987 unique records, of which 196 articles were selected after title and abstract screening. A total of 39 articles were read in full text after quality analysis using Downs and Black criteria; 10 of the studies were excluded due to heterogeneity or inconclusive results. Finally, 30 publications were included in this systematic review. The review revealed that clinical conditions such as obesity, weight change, psoriasis, polycystic ovary syndrome, diabetes, thyroid disorders, and elevated serum uric acid levels increase the risk of developing nonalcoholic fatty liver. In addition, lifestyle factors such as sedentary behavior, active or passive smoking, poor sleep quality, and consumption of carbonated beverages are associated with this condition. Conclusions: Evidence was found on the association between different clinical and lifestyle risk factors and NAFLD. This supports the need for preventive, diagnostic, and therapeutic strategies to improve the metabolic, hepatic, and oncological outcomes related to this condition.