title: Altered amino acid homeostasis in subjects affected by fibromyalgia.
abstract: OBJECTIVE
  To evaluate plasma amino acid (AA) concentrations in patients affected by fibromyalgia (FM) and to study the relationships between their levels and FM clinical parameters.
  
  
  METHODS
  20 AAs were assessed in 34 FM patients and in 18 healthy volunteers by means of a modified version of the Waters picotag method.
  
  
  RESULTS
  Significant lower plasma taurine, alanine, tyrosine (Tyr), valine, methionine, phenylalanine and threonine concentrations, and the sum of essential AAs were observed in FM patients vs healthy controls (P<0.05). Tyr CAA' ratio and the sum of AAs competing with tryptophan for brain uptake were significantly reduced in FM (P<0.05). A significant correlation was found between FM clinical parameters and certain AAs.
  
  
  CONCLUSIONS
  Our results suggest probable defects of gut malabsorption of certain AAs in FM patients. Moreover, given the reduced Tyr CAA' ratio in FM patients, a possible impairment of the cathecolaminergic system in the FM syndrome may be suggested.
authors.affiliation: Department of Internal Medicine, Division of Rheumatology, University of Pisa, Via Roma 67, 56126 Pisa, Italy. l.bazzichi@int.med.unipi.it
authors.forename: Laura
authors.initials: L
authors.lastname: Bazzichi
authors.forename: Lionella
authors.initials: L
authors.lastname: Palego
authors.forename: Gino
authors.initials: G
authors.lastname: Giannaccini
authors.forename: Alessandra
authors.initials: A
authors.lastname: Rossi
authors.forename: Francesca
authors.initials: F
authors.lastname: De Feo
authors.forename: Camillo
authors.initials: C
authors.lastname: Giacomelli
authors.forename: Laura
authors.initials: L
authors.lastname: Betti
authors.forename: Laura
authors.initials: L
authors.lastname: Giusti
authors.forename: Giovanni
authors.initials: G
authors.lastname: Mascia
authors.forename: Stefano
authors.initials: S
authors.lastname: Bombardieri
authors.forename: Antonio
authors.initials: A
authors.lastname: Lucacchini
mesh_terms: D000596:Amino Acids / Q000097:blood* / Q000378:metabolism; D000597:Amino Acids, Branched-Chain / Q000097:blood; D000601:Amino Acids, Essential / Q000097:blood; D000603:Amino Acids, Sulfur / Q000097:blood; D001692:Biological Transport; D016022:Case-Control Studies; D003710:Demography; D005260:Female; D005356:Fibromyalgia / Q000097:blood* / Q000378:metabolism; D006706:Homeostasis; D006801:Humans; D008297:Male; D008875:Middle Aged; D012890:Sleep
chemical_list: D000596:Amino Acids; D000597:Amino Acids, Branched-Chain; D000601:Amino Acids, Essential; D000603:Amino Acids, Sulfur