Smoking and Hair Dyes May Increase Risk of Progressive Liver Disease
Researchers from the UK have found that both smoking and the use of hair dyes may increase the risk of a type of long-term progressive liver disease called primary biliary cirrhosis, or PBC.
The authors base their findings on the evaluation of over 5000 patients between 1997 and 2003 in northeast England. More than 90% were women. Patients with PBC and a group of randomly selected residents used as controls were sent detailed questionnaires on potential environmental and genetic risk factors associated with PBC.
Primary biliary cirrhosis is an early form of primary liver cirrhosis and is considered an autoimmune disease in which environment may play a part in the progression. PBC causes the bile ducts of the liver to become inflamed, scarred and blocked, leading to extensive tissue damage and irreversible liver cirrhosis. It usually occurs between the ages of 40 and 60 and affects women more often than men.
Symptoms usually come on gradually and may include abdominal pain, enlarged liver, fatigue, fatty deposits under the skin, fatty stools, itching, jaundice and soft yellow spots on the eyelid. If not treated, most patients will need a liver transplant after about 7 years.
As expected, many of those with PBC also had other autoimmune diseases such as rheumatoid arthritis, thyroid and celiac disease. Those with a family history of autoimmune diseases were also at a greater risk.
For those with a genetic predisposition for PBC, environmental factors such as exposure to chemicals or infections cause a greater likelihood of the development of the disease.
In the study, patients with PBC were 63% more likely to have smoked at some point in their lives. Women who had used hair dye were 37% more likely to develop PBC. Previous research has found an association between the liver disease and octynoic acid, used in cosmetics such as hair colorings and nail polish.
A specific treatment that stops or reverses the progression of primary biliary cirrhosis has not been found. Therapy goals are aimed at relieving symptoms and preventing complications. Cholestyramine may reduce itching and Ursodeoxycholic acid may improve removal of bile from the blood stream. Vitamin supplements are given to prevent malnutrition and softening of the bones.
Prince M, et al "Case control studies of risk factors for primary biliary cirrhosis in two United Kingdom populations" Gut 2010; 59: 508-12.