title: Age-related differences in plasma BDNF levels after prolonged bed rest.
abstract: Brain-derived neurotrophic factor (BDNF) is a member of the family of neurotrophins and has been implicated in brain resistance to insults. Murine studies have demonstrated increased hippocampal concentration after acute immobilization and decreased concentration after chronic immobilization. In humans, chronic stress and sedentary lifestyle result in decreased plasma BDNF levels, but there no data exist regarding acute immobilization. The aim of our study was to evaluate age-related responses [comparing 7 younger subjects (age 23 ± 3 yr) and 8 older subjects (age 60 ± 4 yr)] of plasma BDNF before (baseline data collection, BDC) and after 14 days (BR14) of horizontal bed rest (BR). At BDC, BDNF levels were not different between the two groups (P = 0.101), although at BR14, BDNF levels were higher in older subjects (62.02 ± 18.31) than in younger subjects (34.36 ± 15.24 pg/ml) (P = 0.002). A general linear model for repeated measures showed a significant effect of BR on BDNF (P = 0.002). The BDC BDNF levels correlated with fat-free mass in both populations (ALL) (R = 0.628, P = 0.012), (older, R = 0.753, P = 0.031; younger, R = 0.772, P = 0.042), and with total cholesterol in ALL (R = 0.647, P = 0.009) and older study subjects (R = 0.805, P = 0.016). At BR14, BDNF correlated with total cholesterol (R = 0.579, P = 0.024) and age (R = 0.647, P = 0.009) in ALL. With an increase in age, the brain could become naturally less resistant to acute stressors, including the detrimental effects of prolonged bed rest, and thus the increase in BDNF in the older study group might reflect a protective overshooting of the brain to counteract the negative effects in such conditions.
authors.affiliation: Medical Science Department, University of Ferrara, Ferrara, Italy; and.
authors.forename: Cecilia
authors.identifier: 0000-0002-6877-274X
authors.initials: C
authors.lastname: Soavi
authors.affiliation: Science and Research Centre, University of Primorska, Capodistria, Slovenia.
authors.forename: Uroš
authors.initials: U
authors.lastname: Marušič
authors.affiliation: Medical Science Department, University of Ferrara, Ferrara, Italy; and.
authors.forename: Juana Maria
authors.initials: JM
authors.lastname: Sanz
authors.affiliation: Medical Science Department, University of Ferrara, Ferrara, Italy; and.
authors.forename: Mario Luca
authors.initials: ML
authors.lastname: Morieri
authors.affiliation: Medical Science Department, University of Ferrara, Ferrara, Italy; and.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Dalla Nora
authors.affiliation: Science and Research Centre, University of Primorska, Capodistria, Slovenia.
authors.forename: Bostjan
authors.initials: B
authors.lastname: Šimunič
authors.affiliation: Science and Research Centre, University of Primorska, Capodistria, Slovenia.
authors.forename: Rado
authors.initials: R
authors.lastname: Pišot
authors.affiliation: Medical Science Department, University of Ferrara, Ferrara, Italy; and.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Zuliani
authors.affiliation: Medical Science Department, University of Ferrara, Ferrara, Italy; and psn@unife.it.
authors.forename: Angelina
authors.initials: A
authors.lastname: Passaro
mesh_terms: D000328:Adult; D000367:Age Factors; D001510:Bed Rest / Q000379:methods; D001921:Brain / Q000378:metabolism / Q000502:physiology; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood*; D002784:Cholesterol / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D019208:Brain-Derived Neurotrophic Factor; C579455:BDNF protein, human; D002784:Cholesterol
keywords: acute stress; aging brain; bed rest; brain-derived neurotrophic factor