Hepatitis B, C may heighten risk of Parkinson's disease later in life: Study

A team of Briton researchers has found viruses of hepatitis B and C may increase the risk of developing a progressive disease of the nervous system marked by tremor, muscular rigidity and slow, imprecise movement later in life.

The findings, published in the online journal of Neurology®, indicated that people with hepatitis B were 76 percent more likely to develop Parkinson's disease, and people with hepatitis C were 51 percent more likely to develop it.

Hepatitis B is spread through contact with blood and body fluids of an infected person, such as unprotected sex, sharing needles, getting a tattoo or piercing with unsterilized tools or sharing razors or toothbrushes with an infected person.

Hepatitis C is spread through blood-to-blood contact such as sharing needles, razors and toothbrushes and is passed on at birth by infected mothers.

"The development of Parkinson's disease is complex, with both genetic and environmental factors," said study author Julia Pakpoor from the University of Oxford in the United Kingdom.

"It's possible that the hepatitis virus itself or perhaps the treatment for the infection could play a role in triggering Parkinson's disease or it's possible that people who are susceptible to hepatitis infections are also more susceptible to Parkinson's disease," Pakpoor added.

The team examined hospital records from a large British database.

They looked for records of people with a first case of hepatitis B, hepatitis C, autoimmune hepatitis, chronic active hepatitis and HIV from 1999 to 2011.

Then those people were compared to the hospital records of people with relatively minor conditions such as cataract surgery, bunions and knee replacement surgery.

For all of the participants, the researchers looked at the records to see who later developed Parkinson's disease.

There were nearly 22,000 people with hepatitis B, 48,000 with hepatitis C, 6,000 with autoimmune hepatitis, 4,000 with chronic active hepatitis and nearly 20,000 with HIV.

However, Pakpoor said that limitations of the current study include that they could not adjust for lifestyle factors such as smoking and alcohol use, which could affect Parkinson's disease risk.