Septicemia is associated with increased risk for dementia: a population-based longitudinal study

Abstract

// Chung-Hsing Chou 1, 2 , Jiunn-Tay Lee 1, 2 , Chun-Chieh Lin 1 , Yueh-Feng Sung 1 , Che-Chen Lin 3 , Chih-Hsin Muo 3 , Fu-Chi Yang 1 , Chi-Pang Wen 4 , I-Kuan Wang 5, 6, 7 , Chia-Hung Kao 5, 8 , Chung Y. Hsu 5 and Chun-Hung Tseng 9 1 Department of Neurology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China 2 Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of China 3 Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan, Republic of China 4 Institute of Population Health Sciences, National Health Research Institutes, Zhunan, Taiwan, Republic of China 5 Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan, Republic of China 6 Department of Internal Medicine, College of Medicine, China Medical University, Taichung, Taiwan, Republic of China 7 Division of Kidney Disease, China Medical University Hospital, Taichung, Taiwan, Republic of China 8 Department of Nuclear Medicine, PET Center, China Medical University Hospital, Taichung, Taiwan, Republic of China 9 Department of Neurology, China Medical University Hospital, Taichung, Taiwan, Republic of China Correspondence to: Jiunn-Tay Lee, email: jiunntay@gmail.com Keywords: septicemia, infection, dementia, Alzheimer’s disease, non-Alzheimer dementias Received: May 17, 2017     Accepted: August 04, 2017     Published: September 15, 2017 ABSTRACT Background: Systemic infection has been linked to cognitive impairment. We hypothesized that patients with septicemia are predisposed to increased risks for developing dementia in a long-term setting. Methods: This observational, retrospective, longitudinal, nation-wide population-based study was conducted using the data deduced from Longitudinal Health Insurance Database (LHID) in Taiwan. All patients with septicemia hospitalized for the first time from 2001 to 2011 without prior dementia were included. The development of Alzheimer’s disease (AD) or non-Alzheimer dementias (NAD) in relation to the development of septicemia for each patient was recorded. An age- and sex-matched cohort without septicemia and without prior dementia served as the control. Septicemia, dementia, and other confounding factors were defined according to International Classification of Diseases Clinical Modification Codes. Cox proportional-hazards regressions were utilized to analyze adjusted hazard ratios. Results: Patients with septicemia had a higher risk for developing dementia based on hazard ratios (HRs) ( p <0.001). Patients with septicemia in the younger age groups had a greater dementia risk ( p <0.01). Septicemia was associated with subsequent NAD ( p <0.001), whereas the increased risk of AD was statistically insignificant ( p >0.05). Furthermore, higher severity of septicemia was associated with increased risk of developing dementia. Conclusions: Our findings suggest that septicemia is associated with an increased risk in developing NAD but not AD. A likely causal role of septicemia in increasing the risk of NAD is suggested, according to the findings that patients with higher severity of septicemia carried greater risk of sustaining dementia.