title: Tissue electric properties in head and neck cancer patients.
abstract: BACKGROUND
  The phase angle of the impedance vector was lower because of a decreased Xc component in hemodialysis patients with poorer prognosis, patients with hemodynamic instability, and in critically ill patients. The phase angle is easy to obtain. The aim of our study was to investigate in a case-control study the utility of phase angle and other impedance parameters in a population of male patients with head and neck cancer.
  
  
  METHODS
  A case-control study was designed. A population of 67 ambulatory post-surgical male patients was enrolled with the following inclusion criteria: oral and/or laryngeal cancer confirmed by biopsy, without a recent loss weight (<5% during previous 3 months) and signed informed consent. As reference group, we selected 70 male subjects from the same geographic region and matched by age, which were selected from a database of healthy people of our hospital. Basal blood sampling was performed for determinations of blood chemistry. Weight, height, body mass index and tetrapolar body electrical bioimpedance were performed in both groups.
  
  
  RESULTS
  A total of 67 head and neck cancer male patients were enrolled, mean age was 58.49 +/- 14.54 years, weight 73.32 +/- 11.4 kg and BMI 28.53 +/- 3.5. A total of 70 controls subjects were studied, mean age was 62.33 +/- 12.4 years. Weight 64.31 +/- 8.38 kg and BMI 24.33 +/- 3.2 were significantly lower than in cancer patients (p < 0.05). Renal function and blood sodium levels were similar in both groups. Anthropometric evaluation in cancer patients showed a mean fat mass lower than control patients (13.9 +/- 6.1 vs. 12.1 +/- 6.1 kg; p < 0.05). In control patients, fat-free mass was higher than in cancer patients (58.7 +/- 8.2 vs. 51.23 +/- 8.4 kg; p < 0.05). In cancer patients, reactance (62.3 +/- 17.2 vs. 56.6 +/- 15.1 ohm; p < 0.05) and phase angle (8.02 +/- 1.3 vs. 6.9 +/- 1.5 degrees ; p < 0.05) were lower than in control patients.
  
  
  CONCLUSIONS
  Impedance in male head and neck cancer patients were characterized by a reduced reactance and phase angle. These early altered tissue electric properties appeared with a normal weight and body mass index.
authors.affiliation: Institute of Endocrinology and Nutrition, Unidad de Apoyo a la Investigación, H Universitario Río Hortega, Sv. Digestive, H Valladolid, Spain. dadluis@yahoo.es
authors.forename: D A
authors.initials: DA
authors.lastname: De Luis
authors.forename: R
authors.initials: R
authors.lastname: Aller
authors.forename: O
authors.initials: O
authors.lastname: Izaola
authors.forename: M C
authors.initials: MC
authors.lastname: Terroba
authors.forename: G
authors.initials: G
authors.lastname: Cabezas
authors.forename: L
authors.initials: L
authors.lastname: Cuellar
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D001823:Body Composition / Q000502:physiology*; D001824:Body Constitution; D001827:Body Height / Q000502:physiology; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D016022:Case-Control Studies; D004553:Electric Conductivity; D017097:Electric Impedance; D006258:Head and Neck Neoplasms / Q000378:metabolism / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis