title: Blood biomarkers indicate mild neuroaxonal injury and increased amyloid β production after transient hypoxia during breath-hold diving.
abstract: To determine whether transient hypoxia during breath-hold diving causes neuronal damage or dysfunction or alters amyloid metabolism as measured by certain blood biomarkers.
  
  
  
  Sixteen divers competing in the national Swedish championship in breath-hold diving and five age-matched healthy control subjects were included. Blood samples were collected at baseline and over a course of 3 days where the divers competed in static apnea (STA), dynamic apnea without fins (DYN1) and dynamic apnea with fins (DYN2).
  
  
  
  Biomarkers reflecting brain injury and amyloid metabolism were analysed in serum (S-100β, NFL) and plasma (T-tau, Aβ42) using immunochemical methods.
  
  
  
  Compared to divers' baseline, Aβ42 increased after the first event of static apnea (p = 0.0006). T-tau increased (p = 0.001) in STA vs baseline and decreased after one of the dynamic events, DYN2 (p = 0.03). Further, T-tau correlated with the length of the apneic time during STA (ρ = 0.7226, p = 0.004) and during DYN1 (ρ = 0.66, p = 0.01).
  
  
  
  The findings suggest that transient hypoxia may acutely increase the levels of Aβ42 and T-tau in plasma of healthy adults, further supporting that general hypoxia may cause mild neuronal dysfunction or damage and stimulate Aβ production.
authors.affiliation: a Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Sahlgrenska University Hospital , Mölndal , Sweden.
authors.forename: Magnus
authors.initials: M
authors.lastname: Gren
authors.affiliation: a Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Sahlgrenska University Hospital , Mölndal , Sweden.|b Department of Neurosurgery , University Hospital , Linköping , Sweden.
authors.forename: Pashtun
authors.initials: P
authors.lastname: Shahim
authors.affiliation: a Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Sahlgrenska University Hospital , Mölndal , Sweden.
authors.forename: Ronald
authors.initials: R
authors.lastname: Lautner
authors.affiliation: c Quanterix , Lexington , MA , USA.
authors.forename: David H
authors.initials: DH
authors.lastname: Wilson
authors.affiliation: a Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Sahlgrenska University Hospital , Mölndal , Sweden.
authors.forename: Ulf
authors.initials: U
authors.lastname: Andreasson
authors.affiliation: d UmanDiagnostics , Umeå , Sweden.
authors.forename: Niklas
authors.initials: N
authors.lastname: Norgren
authors.affiliation: a Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Sahlgrenska University Hospital , Mölndal , Sweden.
authors.forename: Kaj
authors.initials: K
authors.lastname: Blennow
authors.affiliation: a Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Sahlgrenska University Hospital , Mölndal , Sweden.|e Department of Molecular Neuroscience , Reta Lila Weston Laboratories, UCL Institute of Neurology , London , UK.
authors.forename: Henrik
authors.initials: H
authors.lastname: Zetterberg
mesh_terms: D000293:Adolescent; D000328:Adult; D016229:Amyloid beta-Peptides / Q000097:blood*; D062485:Breath Holding; D016022:Case-Control Studies; D004242:Diving / Q000009:adverse effects*; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000097:blood*; D008297:Male; D008875:Middle Aged; D016900:Neurofilament Proteins / Q000097:blood; D010446:Peptide Fragments / Q000097:blood*; D064568:S100 Calcium Binding Protein beta Subunit / Q000097:blood*; D018709:Statistics, Nonparametric; D055815:Young Adult; D016875:tau Proteins / Q000097:blood*
chemical_list: D016229:Amyloid beta-Peptides; D016900:Neurofilament Proteins; D010446:Peptide Fragments; D064568:S100 Calcium Binding Protein beta Subunit; C075222:amyloid beta-protein (1-42); C044882:neurofilament protein L; D016875:tau Proteins
keywords: Amyloid; blood biomarkers; breath-hold diving; hypoxia; neuroaxonal injury; tau