Your liver may become enlarged in cases of poorly controlled diabetes, owing to an accumulation of fat within the substance of the liver. Insulin plays an important part in the metabolism of fat and, when the insulin supply is deficient, the levels in the blood of both glucose and fat may become very high. It is also thought that, when insulin does not work properly (insulin resistance), this fat is much more likely to be laid down in the liver. ‘Fatty liver’ is more common in children and young people with poorly controlled diabetes and sometimes the liver may become greatly enlarged. The only treatment is to improve control of the diabetes, following which the liver will steadily shrink back to its normal size.