Rheumatoid Arthritis Was Negatively Associated with Alzheimer’s Disease: A Population-Based Case-Control Study

Abstract

Some of the prior literature investigated the potential association between rheumatoid arthritis (RA) and Alzheimer's disease (AD) because these two diseases may share similar inflammatory mechanisms. Nevertheless, to date, findings of the previous literature are still controversial, and some methodological limitations were observed in those studies. The aim of this case-control study was to investigate the relationship between prior RA and AD using a large population-based dataset. This study used the Taiwan Longitudinal Health Insurance Database 2005. We included 2271 patients with AD who had received prescriptions for acetylcholinesterase inhibitors (AChEIs) as cases and 6813 patients without AD as controls in this study. In addition, we performed a conditional logistic regression to examine the odds ratio (OR) and 95% confidence interval (CI) for prior RA between cases and controls. The study found that 330 (3.63%) of the total sampled patients had an RA diagnosis before the index date. Additionally, prior RA was found in 60 (2.64%) cases and in 270 (3.96%) controls. The conditional logistic regression analysis showed that the crude OR of prior RA for cases was 0.66 (95% confidence interval (CI): 0.49~0.87) compared to controls. After adjusting for patients’ geographic location, urbanization level, and comorbidities, the adjusted OR of prior RA for patients with AD was 0.73 (95% CI: 0.55~0.98) compared to those without AD. We concluded that there was an inverse association between prior RA and AD even after adjusting for potential confounders.

Can Disease-Modifying Anti-Rheumatic Drugs Reduce the Risk of Developing Dementia in Patients with Rheumatoid Arthritis?

“…However, in the present study, RA was Data are shown as n (%) for qualitative variables. The results were adjusted for age, gender, and all comorbidities RA = rheumatoid arthritis; DMARD = disease-modifying anti-rheumatic drug; cHR = crude hazard ratio; aHR = adjusted hazard ratio; CI = confidence interval negatively associated with dementia, which is consistent with the results of previous studies [8,12,23]. While it has been commonly assumed that NSAID use prohibits the onset of dementia, NSAIDs were not proven to be protective in an AD clinical trial [24].…”

“…Uncontrolled active disease causes joint damage, disability, and decreased quality of life as well as cardiovascular and other comorbidities [11]. Many studies have been conducted to demonstrate the association between autoimmune diseases (e.g., RA) and dementia [12][13][14][15]. However, the results of the studies remain controversial.…”

Alzheimer’s Disease and Rheumatoid Arthritis: A Mendelian Randomization Study

“…RA population had an increased AD risk ( Chou et al, 2016 ). Kao et al (2016) performed a case-control study to evaluate the relationship between prior RA and AD using 2271 patients with AD as cases and 6813 patients without AD as controls. They found an inverse association between prior RA and AD ( Kao et al, 2016 ).…”

“… Kao et al (2016) performed a case-control study to evaluate the relationship between prior RA and AD using 2271 patients with AD as cases and 6813 patients without AD as controls. They found an inverse association between prior RA and AD ( Kao et al, 2016 ). Ungprasert et al (2016) conducted a systematic review and meta-analysis of three cohort studies and two cross-sectional studies.…”

“…They identified eight genetic variants associated with both AD and immune-mediated diseases ( Jiang et al, 2016 ; Yokoyama et al, 2016 ). However, epidemiological studies have reported a controversial inverse relationship between AD and RA ( Ferraccioli et al, 2012 ; Kao et al, 2016 ; Ungprasert et al, 2016 ).…”