title: Hypoaminoacidemia Characterizes Chronic Traumatic Brain Injury.
abstract: Individuals with a history of traumatic brain injury (TBI) are at increased risk for a number of disorders, including Alzheimer's disease, Parkinson's disease, and chronic traumatic encephalopathy. However, mediators of the long-term morbidity are uncertain. We conducted a multi-site, prospective trial in chronic TBI patients (∼18 years post-TBI) living in long-term 24-h care environments and local controls without a history of head injury. Inability to give informed consent was exclusionary for participation. A total of 41 individuals (17 moderate-severe TBI, 24 controls) were studied before and after consumption of a standardized breakfast to determine if concentrations of amino acids, cytokines, C-reactive protein, and insulin are potential mediators of long-term TBI morbidity. Analyte concentrations were measured in serum drawn before (fasting) and 1 h after meal consumption. Mean ages were 44 ± 15 and 49 ± 11 years for controls and chronic TBI patients, respectively. Chronic TBI patients had significantly lower circulating concentrations of numerous individual amino acids, as well as essential amino acids (p = 0.03) and large neutral amino acids (p = 0.003) considered as groups, and displayed fundamentally altered cytokine-amino acid relationships. Many years after injury, TBI patients exhibit abnormal metabolic responses and altered relationships between circulating amino acids, cytokines, and hormones. This pattern is consistent with TBI, inducing a chronic disease state in patients. Understanding the mechanisms causing the chronic disease state could lead to new treatments for its prevention.
authors.affiliation: 1 Department of Internal Medicine, University of Texas Medical Branch , Galveston, Texas.
authors.forename: William J
authors.initials: WJ
authors.lastname: Durham
authors.affiliation: 3 Transitional Learning Center at Galveston , Galveston, Texas.
authors.forename: Jack P
authors.initials: JP
authors.lastname: Foreman
authors.affiliation: 1 Department of Internal Medicine, University of Texas Medical Branch , Galveston, Texas.
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Randolph
authors.affiliation: 1 Department of Internal Medicine, University of Texas Medical Branch , Galveston, Texas.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Danesi
authors.affiliation: 2 Department of Preventive Medicine and Community Health, University of Texas Medical Branch , Galveston, Texas.
authors.forename: Heidi
authors.initials: H
authors.lastname: Spratt
authors.affiliation: 4 University of Arkansas for Medical Sciences , Little Rock, Arkansas.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Masel
authors.affiliation: 5 Centre for Neuro Skills , Bakersfield, California.
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Summons
authors.affiliation: 5 Centre for Neuro Skills , Bakersfield, California.
authors.forename: Charan K
authors.initials: CK
authors.lastname: Singh
authors.affiliation: 5 Centre for Neuro Skills , Bakersfield, California.
authors.forename: Melissa
authors.initials: M
authors.lastname: Morrison
authors.affiliation: 5 Centre for Neuro Skills , Bakersfield, California.
authors.forename: Claudia
authors.initials: C
authors.lastname: Robles
authors.affiliation: 3 Transitional Learning Center at Galveston , Galveston, Texas.
authors.forename: Cindy
authors.initials: C
authors.lastname: Wolfram
authors.affiliation: 5 Centre for Neuro Skills , Bakersfield, California.
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Kreber
authors.affiliation: 1 Department of Internal Medicine, University of Texas Medical Branch , Galveston, Texas.
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Urban
authors.affiliation: 1 Department of Internal Medicine, University of Texas Medical Branch , Galveston, Texas.
authors.forename: Melinda
authors.initials: M
authors.lastname: Sheffield-Moore
authors.affiliation: 3 Transitional Learning Center at Galveston , Galveston, Texas.|6 Brain Injury Association of America , Grapevine, Texas.
authors.forename: Brent E
authors.initials: BE
authors.lastname: Masel
mesh_terms: D000328:Adult; D000596:Amino Acids / Q000097:blood*; D015415:Biomarkers; D000070642:Brain Injuries, Traumatic / Q000097:blood* / Q000175:diagnosis* / Q000628:therapy; D020208:Brain Injury, Chronic / Q000097:blood* / Q000175:diagnosis* / Q000628:therapy; D016207:Cytokines / Q000097:blood*; D005260:Female; D006801:Humans; D008134:Long-Term Care / Q000639:trends; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D000596:Amino Acids; D015415:Biomarkers; D016207:Cytokines
keywords: head trauma; metabolism