Effect of body mass index and alcohol consumption on liver disease: analysis of data from two prospective cohort studies

Objective To investigate whether alcohol consumption and raised body mass index (BMI) act together to increase risk of liver disease. Design Analysis of data from prospective cohort studies. Setting Scotland. Participants Data were from two of the Midspan prospective cohort studies (9559 men): “Main” study 1965-8, participants from workplaces across central belt of Scotland, population of island of Tiree, and mainland relatives, and “Collaborative” study, 1970-3, participants from 27 workplaces in Glasgow, Clydebank, and Grangemouth. Follow-up was to 31 December 2007 (median 29 years, range 0.13-42). We divided participants into nine groups based on measures of body mass index (BMI) (underweight/normal weight Main outcome measures Liver disease morbidity and mortality. Results 80 (0.8%) men died with liver disease as the main cause and 146 (1.5%) with liver disease as any cause. In the Collaborative study, 196 men (3.3%) had liver disease defined by a death, admission, or cancer registration. BMI and alcohol consumption were strongly associated with liver disease mortality in analyses adjusted for other confounders (P=0.001 and P Conclusions Raised BMI and alcohol consumption are both related to liver disease, with evidence of a supra-additive interaction between the two. The occurrence of both factors in the same populations should inform health promotion and public health policies.