Association of Alzhemier's disease with hepatitis C among patients with bipolar disorder.

Herng-Ching Lin,Chung-Chien Huang,Chao-Hung Chen,Sudha Xirasagar,Hsin-Chien Lee

doi:10.1371/journal.pone.0179312

Abstract

Associations of hepatitis C virus infection with Alzheimer’s disease have not been studied among higher risk, bipolar disorder patients. This population-based case-control study investigated the risks of hepatitis C virus infection among Alzheimer’s disease patients with bipolar disorder in the years preceding their Alzheimer’s disease diagnosis. We used 2000–2013 data from the Longitudinal Health Insurance Database in Taiwan. Among patients with bipolar disorder, 73 were diagnosed with Alzheimer’s disease (cases), who were compared with 365 individuals with bipolar disorder but without Alzheimer’s disease (randomly selected controls matched on sex, age, and index year with cases). Prior claims (before the diagnosis year/index year for controls) were screened for a diagnosis of hepatitis C virus infection. Conditional logistic regression models were used for analysis. We found that 23 (31.51%) and 60 (16.44%) patients with bipolar disease were identified with a hepatitis C diagnosis among those with and without Alzheimer’s disease, respectively. Compared to controls, patients with Alzheimer’s disease showed 2.31-fold (95% confidence interval = 1.28–4.16) increased risk of hepatitis C infections adjusted for demographics and socio-economic status. Findings suggest an association of Alzheimer’s disease with a preceding diagnosis of hepatitis C infection among patients with bipolar disorder. Findings may suggest a need for increased awareness of and appropriate surveillance for Alzheimer’s disease in patients with bipolar disorder diagnosed with hepatitis C infection.

Highlights

Bipolar disorder (BD) is a common, disabling mental disorder, with lifetime prevalence rates ranging from 0.8% to 2% [1]
This is the first epidemiological study in the medical literature to assess the association between prior hepatitis C virus (HCV) infection and Alzhemier’s disease (AD) within a population sub-group at high risk for both conditions, bipolar disease patients
In this matched case-control study, we found that 31.5% and 16.4% of AD patients and patients free from AD, respectively, had prior HCV infection

Summary

Introduction

Bipolar disorder (BD) is a common, disabling mental disorder, with lifetime prevalence rates ranging from 0.8% to 2% [1]. Other studies point to an increased risk of infectious diseases among patients with BD likely due to higher-risk behaviors, such as using injectable drugs, having multiple sexual partners and high-risk partners, and infrequent condom use, in addition to the overarching issue of poverty that often accompanies severe mental illness [5,6,7]. Hepatitis C virus (HCV) infection is a contemporary worldwide public health problem with a high disease burden. Among patients with BD, a remarkably elevated risk of HCV infection is reported, with estimated infection rates of 10% to 23.3% [9, 10] compared to 1.8% in the general population [11]

Methods

Results

Conclusion