title: Assessment of biophysical skin properties at different body sites in hospitalized old patients: results of a pilot study.
abstract: BACKGROUND
  Skin aging is a risk factor for a decubitus and biophysical skin properties could help to identify persons at risk. Whether such biophysical properties of aged human skin differ between areas is undetermined.
  
  
  OBJECTIVE
  To investigate whether viscoelasticity, hydration or friction differ between important areas for decubitus risk.
  
  
  METHODS
  Pilot study in 32 (18 female, 14 male) acute and subacute old patients aged 81.9 ± 5.9 years (±SD), without active skin disease after an average of 10 days of stay. Assessment of skin resilience/viscoelasticity (E) and hydration (H) at the volar forearm (VF), trochanter (TR) and the sacrum (SA), nutrition by a Mini Nutritional Assessment (MNA), total body water (TBW), lean body mass (LBM), % body fat (%F) by bioimpedance and routine laboratory parameters (hemoglobin, hematocrit, leukocytes, C-reactive protein, serum proteins and creatinine).
  
  
  RESULTS
  Mean body mass index (27 ± 4.2), MNA (22.5 ± 2.9), Braden score (20 ± 2.5), E (68.5 ± 6.0%) and H (38.3 ± 6.7) at any site and laboratory parameters did not differ by sex. Men had more TBW (+12 ± 1.5 liters), LBM (+9 ± 2 kg), less %F (-8.8 ± 2.1%), increased H-TR (+7.11 ± 2.8) and H-SA (+5.68 ± 2.5). Overall E-VF correlated significantly with E-TR (r(2) = 0.40, p < 0.0001) and E-SA (r(2) = 0.40, p < 0.0001). In contrast, skin hydration was not correlated.
  
  
  CONCLUSIONS
  Results of forearm elasticity experiments can be used as a model for other body sites at risk for the development of pressure ulcers.
authors.affiliation: Geriatrische Klinik, St. Gallen, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Fiedler
authors.forename: L-C
authors.initials: LC
authors.lastname: Gerhardt
authors.forename: S
authors.initials: S
authors.lastname: Derler
authors.forename: G
authors.initials: G
authors.lastname: Bischofberger
authors.forename: C
authors.initials: C
authors.lastname: Hürny
authors.forename: T
authors.initials: T
authors.lastname: Münzer
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001696:Biomechanical Phenomena / Q000502:physiology; D055592:Biophysical Phenomena; D001823:Body Composition; D001834:Body Water / Q000378:metabolism; D004548:Elasticity; D005260:Female; D006801:Humans; D008297:Male; D015596:Nutrition Assessment; D010865:Pilot Projects; D003668:Pressure Ulcer / Q000209:etiology / Q000503:physiopathology; D012307:Risk Factors; D015595:Skin Aging / Q000502:physiology*; D014783:Viscosity