Smoking With Liver Disease - A No-No
In patients who have chronic liver disease that is due to alcohol or viruses, the damage to the liver is primarily caused by the alcohol or virus. However, other factors can modify, or aggravate, the amount of liver damage. An interesting study published in the July issue of the journal, Hepatology, focused specifically on the effect that smoking cigarettes has on the liver damage caused by a common chronic liver disease, hepatitis C.
The authors examined the liver biopsies from 310 patients with chronic hepatitis C who were being hospitalized for their first liver biopsy. They compared the biopsies from patients who were current cigarette smokers (176 patients) or former cigarette smokers (56 patients) with biopsies from patients who had never smoked cigarettes (77 patients). They found that current and former smokers had more inflammation and scarring of their livers than did nonsmokers. This finding could not be explained by other factors, such as concurrent alcohol use, that are known to aggravate the inflammation and scarring in hepatitis C. The authors concluded that patients with chronic hepatitis C should be informed that smoking cigarettes could worsen their liver disease.
Chronic hepatitis C can seriously damage the liver. Any study that suggests a way of lessening the damage is potentially important. As always, however, the question must be asked, how well does the study support the conclusions? How strong is the association between smoking cigarettes and greater liver damage? As we have done several times in other articles, let's look critically at the study.
The study was published in a first tier journal and authors are well-known and respected in the field of liver disease. However, the design of the study, referred to as an observational study, is not the strongest.