title: Serum levels of C-terminal agrin fragment (CAF) are associated with sarcopenia in older hip fractured patients.
abstract: BACKGROUND
  Serum concentrations of the C-terminal fragment of agrin (CAF), a component of the neuromuscular junction (NMJ), are elevated in older community-dwellers with sarcopenia. Whether CAF may be used as a marker for muscle wasting in the presence of NMJ mechanical damage is presently unknown. The present study was undertaken to verify if serum CAF levels were associated with sarcopenia in older hip fractured patients.
  
  
  METHODS
  Analyses were conducted in older adults hospitalized for traumatic hip fracture. The presence of sarcopenia was established according to the European Working Group on Sarcopenia in Older People criteria, with bioelectrical impedance analysis used for muscle mass estimation. Serum levels of CAF were determined using a commercial ELISA kit.
  
  
  RESULTS
  Among 42 hip fractured patients (age 83.7±8.6 years, 76.2% women), sarcopenia was diagnosed in 7 individuals (16.7%). Serum CAF levels were significantly higher in sarcopenic relative to non-sarcopenic patients (172.2±47.5 pM vs. 93.1±44.0 pM; p<0.001). The association remained significant in both genders after adjustment for several potential confounders.
  
  
  CONCLUSIONS
  Elevated serum CAF concentrations are associated with sarcopenia in older adults with hip fracture. The determination of serum CAF levels could therefore serve to identify a subset of hip fractured patients at especially high risk for adverse health outcomes.
authors.affiliation: Department of Geriatrics, Neurosciences and Orthopedics, Catholic University of the Sacred Heart, Rome, Italy. Electronic address: emarzetti@live.com.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Marzetti
authors.affiliation: Department of Geriatrics, Neurosciences and Orthopedics, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Calvani
authors.affiliation: Department of Geriatrics, Neurosciences and Orthopedics, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Lorenzi
authors.affiliation: Department of Chemistry, "Sapienza" University of Rome, Rome, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Marini
authors.affiliation: Department of Geriatrics, Neurosciences and Orthopedics, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: D'Angelo
authors.affiliation: Department of Geriatrics, Neurosciences and Orthopedics, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Martone
authors.affiliation: Department of Geriatrics, Neurosciences and Orthopedics, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Celi
authors.affiliation: Department of Geriatrics, Neurosciences and Orthopedics, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Tosato
authors.affiliation: Department of Geriatrics, Neurosciences and Orthopedics, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Bernabei
authors.affiliation: Department of Geriatrics, Neurosciences and Orthopedics, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Landi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood* / Q000473:pathology; D018171:Agrin / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D015331:Cohort Studies; D005260:Female; D006620:Hip Fractures / Q000097:blood* / Q000150:complications*; D006801:Humans; D008297:Male; D010446:Peptide Fragments / Q000097:blood; D055948:Sarcopenia / Q000097:blood* / Q000150:complications* / Q000175:diagnosis
chemical_list: D018171:Agrin; D015415:Biomarkers; D010446:Peptide Fragments
keywords: Aging; Bioelectrical impedance analysis (BIA); Biomarker; Handgrip; Muscle atrophy; Muscle injury; Neuromuscular junction