title: Gender affects 13C-ketoisocaproic acid breath test.
abstract: OBJECTIVE
  13C-Ketoisocaproic Acid Breath Test (13C-Kica-BT) has been proposed to assess mitochondrial function. Aim of this study is to evaluate whether gender affects mithocondrial oxidation by means of 13C-Kica-BT in healthy subjects in basal conditions and after an acute oxidative stress induced by ethanol.
  
  
  METHODS
  50 healthy volunteers were given 1 mg/kg of 13C-Kica together with 20 mg/kg of L-leucine dissolved in 200 ml of orange juice. Breath samples were taken at baseline, every 5 minutes for 45 minutes and then every 15 minutes until 2 hours. Forty-eight hours later the test was repeated 30 min after ethanol ingestion (0.5 g/kg body weight). 13CO2 enrichment in breath was analyzed by isotope ratio/mass spectrometry. Statistical analysis was performed using the student's t test.
  
  
  RESULTS
  At baseline conditions, the percentage of Ketoisocaproic acid in 2 hours was significantly higher in females than in males. Ethanol significantly reduces the oxidation of Ketoisocaproic acid. Conversely, no differences were observed between groups after the ethanol oral load.
  
  
  CONCLUSIONS
  Decarboxylation of 13C-Kica was significantly higher in females than in males. Ethanol decreases Kica decarboxylation in particular in women. Further studies remain needed to establish whether sexual hormones could interfere with the metabolism of Kica.
authors.affiliation: Internal Medicine Department, Catholic University of Rome, Italy. mcandelli@gmail.com
authors.forename: M
authors.initials: M
authors.lastname: Candelli
authors.forename: A
authors.initials: A
authors.lastname: Armuzzi
authors.forename: L
authors.initials: L
authors.lastname: Miele
authors.forename: E C
authors.initials: EC
authors.lastname: Nista
authors.forename: G
authors.initials: G
authors.lastname: Pignataro
authors.forename: L
authors.initials: L
authors.lastname: Zileri Dal Verme
authors.forename: A
authors.initials: A
authors.lastname: Grieco
authors.forename: G
authors.initials: G
authors.lastname: Gasbarrini
authors.forename: A
authors.initials: A
authors.lastname: Gasbarrini
mesh_terms: D000328:Adult; D001944:Breath Tests; D002245:Carbon Dioxide / Q000032:analysis; D002247:Carbon Isotopes; D003653:Decarboxylation; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007651:Keto Acids / Q000378:metabolism*; D007930:Leucine / Q000378:metabolism; D008297:Male; D013058:Mass Spectrometry; D008930:Mitochondria, Liver / Q000378:metabolism*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D012737:Sex Factors; D013997:Time Factors
chemical_list: D002247:Carbon Isotopes; D007651:Keto Acids; D002245:Carbon Dioxide; D000431:Ethanol; C013082:alpha-ketoisocaproic acid; D007930:Leucine