Joint associations of adiposity and alcohol consumption with liver disease-related morbidity and mortality risk: findings from the UK Biobank

Abstract

Background The incidence of both non-alcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (ALD) are expected to grow as a consequence of the ongoing obesity and alcohol consumption trends. Objective We examined the joint associations of adiposity (body mass index (BMI) and waist circumference (WC)) and alcohol consumption on ALD, NAFLD and liver disease incidence and mortality (n = 465,437). Methods Alcohol consumption was categorised based on current UK guidelines (14 units/week). Data were analysed using Cox proportional hazard models. A total of 1090 liver disease deaths, 230 ALD deaths and 192 NAFLD deaths occurred over an average follow-up length of 10.5 ± 1.7 years. Results In multivariate models, we observed greater point estimates for risk of ALD, NAFLD and liver disease incidence and mortality among overweight/obese participants who consumed alcohol at the same level as normal weight participants. We found that overweight/obese participants who reported alcohol consumption above the guidelines had a greater HR for liver disease incidence and mortality (HR 1.52, 95% CI 1.32, 1.75 and HR 2.20, 95% CI 1.41, 3.44, respectively) than normal weight individuals (HR 0.95, 95% CI 0.83, 1.09 and HR 1.24, 95% CI 0.8, 1.93, respectively). The results for the associations of alcohol consumption and WC with ALD, NAFLD and liver disease mortality were similar. Participants with high WC who reported alcohol consumption above the guidelines had a greater HR for liver disease incidence (HR 1.59, 95% CI 1.35, 1.87) than normal WC individuals (HR 0.85, 95% CI 0.72, 1.01). Conclusions We found evidence that being overweight/obese amplified the harmful effect of alcohol on the liver incidence and mortality.