Men with more than normal body weight from an early age (17-19 years) are at higher risk of developing severe liver disease and even liver cancer in later life. The risk is increased when such men develop diabetes.

The association between body weight and higher risk of severe liver disease has become clear in a study based on data of more than 1.2 million Swedish men enlisted for military conscription between 1969 and 1996. Compared with men who have normal weight, those who are overweight (body mass index more than 25 kg/m²) have about 50% greater risk and obese men (BMI greater than 30 kg/m²) are more than twice likely to develop liver disease and even liver cancer in later life.

An earlier study involving nearly 50,000 men showed an association between high BMI in early age was associated with increased risk of end-stage liver disease. The study was based on data collected between 1969-70, when overweight and obesity were relatively uncommon — only 0.8% were overweight. So the study was not statistically powered to confirm an association between high BMI and increased risk of end-stage liver disease.

But a paper published today (March 21) in the journal Gut found a statistically significant association between BMI and severe liver disease. Men who have higher BMI even at an early age are at higher risk of developing severe liver disease and liver cancer as the “duration of being exposed to a high BMI” increases the risk.

Compared with men with BMI 18.5-22.5 kg/m², men with higher BMI had higher risk of severe liver disease, with the greatest risk in those with BMI greater than 30 kg/m². The non-alcoholic fatty liver disease is likely to be the “main driver” of severe liver disease in adolescent men, the study says.

Consumption of alcohol and smoking were taken into account and those who had developed alcoholic liver disease were excluded from the final analysis, but this did not change the overall finding. But the risk of severe liver disease was “highly affected” by development of type 2 diabetes during follow-up across all BMI categories.

It is well known that people with high BMI are at increased risk of developing diabetes, which in turn is associated with heightened risk of developing severe liver disease. Yet, increased risk of severe liver disease was seen even in overweight men who did not have diabetes. As the data was restricted to men, the researchers could not study the association between BMI and severe liver diseases in women. But they say that earlier studies of middle-aged women in the UK have shown found an association; but the risk was “uncertain” for younger women.

Therefore, even if the risk is increased in overweight and obese men who develop diabetes, the association of high BMI at an early age and severe liver disease at a later date “cannot solely be explained” by type 2 diabetes, the study says.

There should be targeted intervention to prevent diabetes and more than normal BMI at an early age.

Published in The Hindu on March 21, 2017