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[P3–246]: SERUM S100B MEDIATES DEPRESSION's EFFECT ON COGNITION
Author(s) -
Rubaye Safa,
Royall Donald R.,
Palmer Raymond F.
Publication year - 2017
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2017.06.1459
Subject(s) - structural equation modeling , biomarker , depression (economics) , mediation , cohort , dementia , medicine , geriatric depression scale , mood , psychology , clinical psychology , oncology , apolipoprotein e , longitudinal study , cognition , psychiatry , disease , depressive symptoms , pathology , biology , genetics , statistics , mathematics , political science , law , economics , macroeconomics
Lacunar number (n1⁄4151) RR (95%CI)* White matter hyperintensities Mean difference (95%CI)* Background:The latent variable “d” (for “dementia”) appears to be uniquely responsible for the dementing aspects of cognitive impairment. Age, depression, and the apolipoprotein E (APOE) e4 allele are independently associated with d. S100b is a calciumbinding protein that is secreted mainly by astrocytes. S100b has been identified as a biomarker for mood/ depressive disorders. In addition, Brain level of S100b is altered in response to chronic use of anti-depressants. In this analysis, we combine SEM (Structural Equation Model) with longitudinal data from the Texas Alzheimer’s Research and Care Consortium (TARCC) to explore whether S100b is a mediator of depression’s specific effect on d. Methods: We employed structural equation models (SEM) to examine the mediation effect of S100b on depression’s association with d in a well characterized cohort (TARCC). Subjects included n1⁄4 3385 TARCC participants [1240 cases of Alzheimer’s Disease (AD), 688 “Mild Cognitive Impairment “(MCI) cases, and 1384 normal controls (NC)]. Serum S100b levels were determined at baseline by Luminex assay (Rules Based Medicine /Austin, TX). All observed measures were adjusted for education, ethnicity, gender, Geriatric Depression Scale (GDS) scores, Hb1Ac, apoE4 and HCY. S100b was additionally adjusted for batch effects. We used an ethnicity equivalent d homolog (i.e., “dEQ”). Wave 2 dEQ scores were used. Thus, the model is longitudinal and arguable causal. Furthermore, we randomly divided the cohort into 2 groups. Group A (n 1⁄4 1691) was used to construct the model, while Group B (n1⁄41694) was used to replicate and verify the parameters of interest. Analyses were conducted in Analysis of Moment Structures (AMOS). Results: Model fit was excellent [c2 1⁄4 519.912(49), p 1⁄40.0; CFI 1⁄4 0.89; RMSEA 1⁄4 0.053]. Serum S100b was found to mediate 18.3% of depression’s association with Wave 2 dEQ scores (p<0.001). The effect generalized across random subsets of TARCC’s sample. Conclusions:S100B plays a role in mediating depression’s independent effects on dementia severity. High levels of serum S100B are dementing. S100B is a possible serum biomarker of depression in the elderly. S100B is a target for rational anti-dementia intervention, and may be amenable to modulation by SSRI. Plasma Ab1-38 Older cohort 1.28 (1.10-1.49) 0.01 (-0.10; 0.13) Younger cohort 1.71 (1.38-2.12) 0.05 (0.00; 0.10) Meta-analysis 1.41 (1.24-1.59) 0.04 (0.00; 0.09) Plasma Ab1-40 P3-247 PLASMA UREA IN ALZHEIMER’S DISEASE: AN OBSERVATIONAL STUDY