Obesity, overweight and liver disease in the Midspan prospective cohort studies

To analyse the relationship between body mass index (BMI) and liver disease in men and women.

The Midspan prospective cohort studies.

The three studies were: Main study, screened in 1965-1968, workplaces across Scotland, the general population of the island of Tiree and mainland relatives; Collaborative study, conducted from 1970 to 1973, 27 workplaces in Glasgow, Clydebank and Grangemouth; Renfrew/Paisley general population study, screened in 1972-1976. After exclusions there were 16 522 men and 10 216 women, grouped by BMI into under/normal weight (< 25 kg m(-2)), overweight (25 to < 30 kg m(-2)) and obese (>or=30 kg m(-2)).

Relative rates (RRs) of liver disease mortality, subdivided into liver cancer and all other liver disease, by BMI category and per s.d. increase in BMI, followed-up to end 2007. RRs of liver disease from any diagnosis on the death certificate, hospital discharge records or cancer registrations (Collaborative and Renfrew/Paisley studies only 13 027 men and 9328 women). Analyses adjusted for age and study, then other confounders.

In total, 146 men (0.9%) and 61 women (0.6%) died of liver disease as main cause. There were strong associations of BMI with liver disease mortality in men (RR per s.d. increase in BMI=1.41 (95% confidence interval 1.21-1.65)). Obese men had more than three times the rate of liver disease mortality than under/normal weight men. Adjustment for other risk factors had very little effect. No substantial or robust associations were observed in women. In all, 325 men (2.5%) and 155 women (1.7%) had liver disease established from any source. Similar positive associations were observed for men, and there was evidence of a relationship in women.

BMI is related to liver disease, although not to liver disease mortality in women. The current rise in overweight and obesity may lead to a continuing epidemic of liver disease.