title: Vascular biomarkers to predict response to exercise in Alzheimer's disease: the study protocol.
abstract: Exercise interventions are a promising treatment for improving cognition in persons with Alzheimer's disease. This is similar to Alzheimer's disease pharmacotherapies in which only 18-48% of treated patients demonstrate improvement in cognition. Aerobic exercise interventions positively affect brain structure and function through biologically sound pathways. However, an under-studied mechanism of aerobic exercise's effects is n-3 fatty acids in plasma. The objective of this pilot study is to inform a future large-scale study to develop n-3 fatty acids-based prediction of cognitive responses to aerobic exercise treatment in Alzheimer's disease.
  
  
  
  This study will recruit and follow a cohort of 25 subjects enrolled in the FIT-AD Trial, an ongoing randomised controlled trial that investigates the effects of a 6-month moderate-intensity cycling intervention on cognition and hippocampal volume in older adults with mild to moderate Alzheimer's disease over a year. This study will collect blood from subjects at baseline and at 3 and 6 months to assay vascular biomarkers (ie, plasma fatty acids). Global cognition as measured by the Alzheimer's Disease Assessment Scale-Cognition (ADAS-Cog) at baseline, 3, 6, 9 and 12 months will be used as the main outcome. A multiple linear-regression model will be used with 12-month change in cognition as the outcome and baseline measure of n-3 fatty acids or changes in the ratio of n-3 to n-6 fatty-acid levels in plasma at 3 and/or 6 months, randomised treatment group, and their interaction as predictors.
  
  
  
  We have obtained Institutional Review Board approval for our study. We obtain consent or assent/surrogate consent from all subjects depending on their consenting capacity assessment. Data of this study are/will be stored in the Research Electronic Data Capture (REDCap). We plan to present and publish our study findings through presentations and manuscripts.
  
  
  
  NCT01954550.
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Minnesota, Twin Cities, Minneapolis, Minnesota, USA.
authors.forename: Danni
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Minnesota, Twin Cities, Minneapolis, Minnesota, USA.
authors.forename: Robin
authors.initials: R
authors.lastname: Thomas
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Minnesota, Twin Cities, Minneapolis, Minnesota, USA.
authors.forename: Michael Y
authors.initials: MY
authors.lastname: Tsai
authors.affiliation: Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Twin Cities, Minneapolis, Minnesota, USA.
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.affiliation: Division of Biostatistics, School of Public Health, University of Minnesota, Twin Cities, Minneapolis, Minnesota, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Vock
authors.affiliation: School of Nursing, University of Minnesota, Twin Cities, Minneapolis, Minnesota, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Greimel
authors.affiliation: School of Nursing, University of Minnesota, Twin Cities, Minneapolis, Minnesota, USA.
authors.forename: Fang
authors.initials: F
authors.lastname: Yu
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000097:blood / Q000523:psychology / Q000628:therapy*; D001057:Apolipoproteins E / Q000097:blood*; D001642:Bicycling; D015415:Biomarkers; D002985:Clinical Protocols; D003071:Cognition; D018450:Disease Progression; D005081:Exercise Therapy / Q000523:psychology; D015525:Fatty Acids, Omega-3 / Q000097:blood*; D005260:Female; D006624:Hippocampus / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota; D010865:Pilot Projects; D011237:Predictive Value of Tests; D012107:Research Design; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D001057:Apolipoproteins E; D015415:Biomarkers; D015525:Fatty Acids, Omega-3
keywords: Alzheimer’s disease; Exercise; Fatty Acids; Phospholipids; Vascular biomarkers