The combined effect of alcohol and body mass index on risk of chronic liver disease: a systematic review and meta-analysis of cohort studies.

Glyn-Owen, Kate; Böhning, Dankmar; Parkes, Julie; Roderick, Paul; Buchanan, Ryan

BACKGROUND & AIMS Increasingly populations are both overweight/obese and consume alcohol. The risk of liver disease from the combination of these factors is unclear. We performed a systematic review and meta-analysis to address this important gap in evidence. Protocol registered with PROSPERO(CRD42016046508). METHODS We performed electronic searches of Ovid Medline, Embase Classic + Embase, until 17th June 2020 for cohort studies of adults without pre-existing liver disease. Primary outcome was morbidity/mortality from chronic liver disease. Exposures were alcohol consumption categorised as within or above UK recommended limits (14 units/112g per week) and BMI categorised as normal, overweight or obese. Non-drinkers were excluded. A Poisson regression log-linear model was used to test for statistical interaction between alcohol and BMI and to conduct a one-stage meta-analysis. RESULTS Searches identified 3,129 studies - 16 were eligible. Of these, nine cohorts (1,121,514 participants) had data available and were included in the analysis. The Poisson model showed no significant statistical interaction between alcohol consumption and BMI on risk of chronic liver disease. Compared to normal weight participants drinking alcohol within UK recommended limits, relative risk of chronic liver disease in overweight participants drinking above limits was 3.32 (95%CI 2.88 to 3.83) and relative risk in obese participants drinking above limits was 5·39 (95%CI 4.62 to 6·29). CONCLUSIONS This meta-analysis found the combination of alcohol consumption above recommended limits and overweight/obesity was associated with a significantly increased risk of chronic liver disease. This evidence should inform advice given to patients and risk stratification by healthcare professionals.