P2‐032: Inflammatory biomarkers in the Texas Alzheimer's Research and Care Consortium (TARCC) Cohort
Year: 2011
Type: article
Study design: Observational Study
Abstract: We tested the hypothesis that Alzheimer's disease (AD) patients demonstrate a significantly different inflammatory profile relative to healthy controls. Recognizing the relationship between inflammatory markers and cardiovascular disease, we further examined whether cardiovascular disease or its risk factors accounted for any differences. We classified AD patients and controls by standardized procedures. We analyzed levels of ten inflammatory biomarkers in serum from N = 197 AD cases and N = 198 controls enrolled in the longitudinal TARCC study using a multiplex assay performed by Rules Based Medicine (Austin, TX). Pre-specified markers included: IL1ra, IL1beta, IL4, IL6, IL8, IL10, IFN gamma, C Reactive Protein (CRP) and TNF alpha. After inspection of distributions variables were dichotomized around the median (except TNF alpha, dichotomized at the 10 percentile). We defined cardiovascular disease equivalent (CVDE) as either: 1. History of MI, cardiac arrest, angina pectoris, angioplasty/endarterectomy/stent, cardiac bypass, congestive heart failure, stroke or TIA; or 2. History of diabetes mellitus; or 3. Any two of the following-history of hypertension or on antihypertensives, history of hypercholesterolemia or on cholesterol lowering drugs, current cigarette smoking. We used Fisher's exact test (unadjusted) and logistic regression (adjusted) to assess whether biomarker levels predicted case-control status. In the adjusted models, we covaried age, sex and body mass index (BMI) and re-calculated final adjusted p values using false discovery rate (FDR) to account for multiple comparisons. We investigated a potential interaction effect between CVDE and each significant variable. AD cases were older (p < 0.0001) and had lower BMI (p = 0.0006) but substantial percentages of each group had CVDE (48% of AD cases, 46% of controls). IL1ra, IFN gamma, and CRP were significantly lower in AD cases (OR 0.51, 0.55, 0.50, respectively) in adjusted and unadjusted models corrected for multiple comparisons. We excluded IL1beta due to insufficient samples above the least detectable dose. Interaction with CVDE did not significantly explain the observed differences. In carefully characterized AD patients and controls, three inflammatory analytes were significantly lower in AD cases, after adjusting for age, sex and body mass index. The differences were not due to different rates of cardiovascular disease or its risk factors and could be due to reduction of BMI in AD cases.
Source: Alzheimer s & Dementia
Institutions: Baylor College of Medicine, The University of Texas Health Science Center at Houston, University of North Texas Health Science Center, Texas Tech University, Texas Tech University Health Sciences Center, The University of Texas Southwestern Medical Center, The University of Texas at San Antonio Health Science Center
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W2028140647