The hepatitis C virus may be associated with an increased risk of developing Parkinson’s disease, according to a study published in the December 23, 2015, online issue of Neurology. Parkinson’s disease is considered the second most common degenerative brain disorder after Alzheimer’s disease. Hepatitis C is a liver infection caused by a virus.
“Many factors clearly play a role in the development of Parkinson’s disease, including environmental factors,” said study author Chia-Hung Kao, MD, China Medical University in Taichung, Taiwan. “This nation-wide study, using the National Health Insurance Research Database of Taiwan, suggests that hepatitis caused specifically by the hepatitis C virus may increase the risk of developing the disease. More research is needed to investigate this link.”
The World Health Organization estimates that 130 to 150 million people have hepatitis C worldwide. While hepatitis C can lead to serious illness, many people have few symptoms and do not realize they have the virus, especially at first.
The virus is transmitted through sharing needles, needle stick injuries in health care providers and passed on at birth from infected mothers. In Taiwan during the time of the study, blood transfusions were the most common cause of the virus. In the United States, all donated blood has been screened for the virus since 1992.
The study involved 49,967 people with hepatitis and 199,868 people without hepatitis. Participants with hepatitis were placed into three groups: those infected with the hepatitis B virus (71 percent), those with hepatitis C (21 percent), and those who had both viruses (8 percent).
The participants were followed for an average of 12 years to see who developed Parkinson’s disease. Of those with hepatitis, 270 developed Parkinson’s disease, including 120 people with hepatitis C. Among those who did not have hepatitis, 1,060 developed Parkinson’s disease.
Once researchers controlled for factors such as age, sex, diabetes and cirrhosis, they found that people with hepatitis C were nearly 30 percent more likely to develop Parkinson’s disease than the people who did not have hepatitis.
People with hepatitis B and those with both viruses were not more or less likely to develop Parkinson’s than those who did not have hepatitis.
About this neurology research
Funding: This study was supported by the Taiwan Ministry of Health and Welfare, China Medical University Hospital, Academia Sinica Taiwan Biobank, Stroke Biosignature Project, NRPB Stroke Clinical Trial Consortium, Tseng-Lien Lin Foundation, Taiwan Brain Disease Foundation, Katsuzo and Kiyo Aoshima Memorial Funds and CMU under the Aim for Top University Plan of the Ministry of Education.
Source: Rachel Seroka – AAN Image Credit: The image is credited to Center for the Study of Hepatitis C, The Rockefeller University and is in the public domain Original Research:Abstract for “Hepatitis C virus infection as a risk factor for Parkinson disease: A nationwide cohort study” by Hsin-Hsi Tsai, Horng-Huei Liou, Chih-Hsin Muo, Cha-Ze Lee, Ruoh-Fang Yen, and Chia-Hung Kao in Neurology. Published online December 23 2015 doi:10.1212/WNL.0000000000002307
Hepatitis C virus infection as a risk factor for Parkinson disease: A nationwide cohort study
Objective: To determine whether hepatitis C virus (HCV) infection is a risk factor for developing Parkinson disease (PD).
Methods: This nationwide population-based cohort study was based on data obtained from a dataset of the Taiwan National Health Insurance Research Database for the period 2000 to 2010. A total of 49,967 patients with viral hepatitis were included for analysis. Furthermore, 199,868 people without viral hepatitis were included for comparisons. Patients with viral hepatitis were further grouped into 3 cohorts: hepatitis B virus (HBV) infection, HCV infection, and HBV-HCV coinfection. In each cohort, we calculated the incidence of developing PD. A Cox proportional hazards model was applied to estimate the risk of developing PD in terms of hazard ratios (HRs) and 95% confidence intervals (CIs).
Results: The crude HRs for developing PD was 0.66 (95% CI = 0.55–0.80) for HBV infection, 2.50 (95% CI = 2.07–3.02) for HCV infection, and 1.28 (95% CI = 0.88–1.85) for HBV-HCV coinfection. The association between HCV and PD remained statistically significant after adjustments for age, sex, and comorbidities (adjusted HR = 1.29, 95% CI = 1.06–1.56).
Conclusions: We conducted a large nationwide population-based study and found that patients with HCV exhibit a significantly increased risk of developing PD.
“Hepatitis C virus infection as a risk factor for Parkinson disease: A nationwide cohort study” by Hsin-Hsi Tsai, Horng-Huei Liou, Chih-Hsin Muo, Cha-Ze Lee, Ruoh-Fang Yen, and Chia-Hung Kao in Neurology. Published online December 23 2015 doi:10.1212/WNL.0000000000002307