Published online Oct 27, 2019. doi: 10.4254/wjh.v11.i10.710
Peer-review started: May 14, 2019
First decision: June 13, 2019
Revised: August 3, 2019
Accepted: October 15, 2019
Article in press: October 15, 2019
Published online: October 27, 2019
Fatty liver disease caused by excess alcohol consumption is called alcoholic liver disease (ALD) whereas fatty liver disease caused by metabolic disease is called non-alcoholic fatty liver disease (NAFLD). Often, risk factors for both types of fatty liver diseases occur in the same individual, especially as the prevalence of both of these diseases is on the rise. The presence of both types of fatty liver disease in one individual may lead to the development of a new condition we call both alcoholic and NAFLD (BAFLD). We believe that patients with BAFLD are at a higher risk of advanced fibrosis and complications related to end-stage liver disease. Studying and understanding BAFLD has important public health and policy implications.
A new fatty liver entity, we call BAFLD, occurs when both ALD and NAFLD risk factors are present in the same individual. We reported on the clinical characteristics and degree of liver fibrosis in BAFLD patients compared to NAFLD patients. As most of the risk factors that lead to BAFLD are modifiable dietary and lifestyle choices, understanding their reciprocal interaction and combined effect on the liver might lead to a better understanding of BAFLD pathogenesis, treatment, and prevention. This has important public health and policy implications.
This study aimed to identify the prevalence of NAFLD and BAFLD and to assess the clinical characteristics of patients with BAFLD in comparison to those with NAFLD in a large cohort of subjects in the United States.
This is a cross-sectional study that was done using National Health and Nutrition Examination Survey between 2003-2014. NAFLD and BAFLD patients were identified. Univariable and multivariable analysis were performed to assess differences between NAFLD and BAFLD and to compare severity based on a validated fibrosis score (FIB4 index).
The prevalence of NAFLD was at 25.9% and that of BAFLD was 0.84% which corresponds to an estimated 1.24 million Americans affected by BAFLD. Compared to NAFLD, patients with BAFLD were more likely to be male, smokers, have higher ALT, AST, triglycerides, and lower platelets; P < 0.01 for all. More importantly, after adjusting for MetS components, BAFLD patients were significantly about three times more likely to have advanced fibrosis based on FIB4 index > 2.67, P = 0.004].
In conclusion, a substantial percentage of the general American population may have BAFLD. Patients with BAFLD tend to have more advanced disease and may have a higher risk of progression to cirrhosis and end-stage liver disease. Therefore, special attention should be paid to this population to identify the burden of liver disease and intervene in a timely fashion.
The possibility of the combined effects of MetS and alcohol consumption should be considered in all patients with suspected NAFLD. Vitally, consideration should be given to the role of screening for identification of risky, often under-reported, alcohol consumption. Data on safe alcohol consumption in NAFLD is conflicting and needs further assessment in future prospective studies.