title: APOEε4 impacts up-regulation of brain-derived neurotrophic factor after a six-month stretch and aerobic exercise intervention in mild cognitively impaired elderly African Americans: A pilot study.
abstract: Possession of the Apolipoprotein E (APOE) gene ε4 allele is the most prevalent genetic risk factor for late onset Alzheimer's disease (AD). Recent evidence suggests that APOE genotype differentially affects the expression of brain-derived neurotrophic factor (BDNF). Notably, aerobic exercise-induced upregulation of BDNF is well documented; and exercise has been shown to improve cognitive function. As BDNF is known for its role in neuroplasticity and survival, its upregulation is a proposed mechanism for the neuroprotective effects of physical exercise. In this pilot study designed to analyze exercise-induced BDNF upregulation in an understudied population, we examined the effects of APOEε4 (ε4) carrier status on changes in BDNF expression after a standardized exercise program. African Americans, age 55years and older, diagnosed with mild cognitive impairment participated in a six-month, supervised program of either stretch (control treatment) or aerobic (experimental treatment) exercise. An exercise-induced increase in VO2Max was detected only in male participants. BDNF levels in serum were measured using ELISA. Age, screening MMSE scores and baseline measures of BMI, VO2Max, and BDNF did not differ between ε4 carriers and non-ε4 carriers. A significant association between ε4 status and serum BDNF levels was detected. Non-ε4 carriers showed a significant increase in BDNF levels at the 6month time point while ε4 carriers did not. We believe we have identified a relationship between the ε4 allele and BDNF response to physiologic adaptation which likely impacts the extent of neuroprotective benefit gained from engagement in physical exercise. Replication of our results with inclusion of diverse racial cohorts, and a no-exercise control group will be necessary to determine the scope of this association in the general population.
authors.affiliation: Department of Physiology and Biophysics, Howard University College of Medicine, Washington, DC, USA.
authors.forename: Joanne S
authors.initials: JS
authors.lastname: Allard
authors.affiliation: Department of Nutritional Sciences, School of Nursing and Allied Health Sciences, Howard University, Washington, DC, USA.
authors.forename: Oyonumo
authors.initials: O
authors.lastname: Ntekim
authors.affiliation: Division of Geriatrics, Department of Medicine, Howard University Hospital, Washington, DC, USA.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Johnson
authors.affiliation: Department of Internal Medicine, Howard University Hospital, Washington, DC, USA.
authors.forename: Julius S
authors.initials: JS
authors.lastname: Ngwa
authors.affiliation: Division of Geriatrics, Department of Medicine, Howard University Hospital, Washington, DC, USA.
authors.forename: Vernon
authors.initials: V
authors.lastname: Bond
authors.affiliation: Department of Physiology and Biophysics, Howard University College of Medicine, Washington, DC, USA.
authors.forename: Dynell
authors.initials: D
authors.lastname: Pinder
authors.affiliation: Department of Internal Medicine, Howard University Hospital, Washington, DC, USA.
authors.forename: Richard F
authors.initials: RF
authors.lastname: Gillum
authors.affiliation: Department of Nutritional Sciences, School of Nursing and Allied Health Sciences, Howard University, Washington, DC, USA.
authors.forename: Thomas V
authors.initials: TV
authors.lastname: Fungwe
authors.affiliation: Department of Community and Family Medicine, Howard University Hospital, Washington, DC, USA.
authors.forename: John
authors.initials: J
authors.lastname: Kwagyan
authors.affiliation: Division of Geriatrics, Department of Medicine, Howard University Hospital, Washington, DC, USA. Electronic address: tobisesan@howard.edu.
authors.forename: Thomas O
authors.initials: TO
authors.lastname: Obisesan
mesh_terms: D001741:Black or African American / Q000235:genetics*; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D053327:Apolipoprotein E4 / Q000235:genetics*; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood*; D003071:Cognition / Q000502:physiology; D060825:Cognitive Dysfunction / Q000235:genetics* / Q000628:therapy*; D015444:Exercise / Q000502:physiology*; D005081:Exercise Therapy / Q000379:methods; D005260:Female; D020022:Genetic Predisposition to Disease; D006579:Heterozygote; D006801:Humans; D008297:Male; D010865:Pilot Projects
chemical_list: D053327:Apolipoprotein E4; D019208:Brain-Derived Neurotrophic Factor
keywords: APOE; Aerobic exercise; African Americans; BDNF; Mild cognitive impairment; Oxygen consumption