title: Dermal factors influencing measurement of skin autofluorescence.
abstract: BACKGROUND
  Skin autofluorescence (SAF) is a noninvasive marker of accumulation of advanced glycation end products. It predicts cardiovascular complications and mortality in diabetes and renal failure. We assessed the influence of potential common confounders in SAF measurement, by determining the effects of endogenous and exogenous local dermal changes by body creams, hyperemia, vasoconstriction, and hydration.
  
  
  METHODS
  SAF was measured before and after local administration of body lotion, day cream, sunscreen, or self-browning cream and after attempts to remove these effects with alcohol swabs and washing. SAF was measured before and during three hyperemia maneuvers: vasoconstriction and on a dry and wet skin.
  
  
  RESULTS
  The body lotion increased SAF by 18%. Day cream, sunscreen, and self-browning cream gave an increase of >100%. Except for body lotion, subsequent cleaning with alcohol swabs and washing with soap did not return SAF to baseline values. The effect of self-browning cream persisted for 2 weeks and that of sunscreen for 4 days. Hyperemia caused by a hot bath, capsicum cream, or postocclusive reactive hyperemia gave a decrease in SAF of, respectively, 18%, 22%, and 2.3%. Vasoconstriction caused by immersing the arm in cold water gave a 10% increase. Hydration state did not influence SAF.
  
  
  CONCLUSIONS
  Measurement of SAF is strongly affected by several skin creams. This effect was often not fully corrected by alcohol swabs and washing with soap and may persist for many days. Marked hyperemia and vasoconstriction also influence SAF. We advise avoiding these potential error sources.
authors.affiliation: Division of Vascular Medicine, Department of Internal Medicine, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands. m.j.noordzij@int.umcg.nl
authors.forename: Margaretha J
authors.initials: MJ
authors.lastname: Noordzij
authors.forename: Joop D
authors.initials: JD
authors.lastname: Lefrandt
authors.forename: Reindert
authors.initials: R
authors.lastname: Graaff
authors.forename: Andries J
authors.initials: AJ
authors.lastname: Smit
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers; D002318:Cardiovascular Diseases / Q000378:metabolism; D003920:Diabetes Mellitus / Q000378:metabolism; D005260:Female; D005453:Fluorescence; D017127:Glycation End Products, Advanced / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009824:Ointments; D051437:Renal Insufficiency / Q000378:metabolism; D012867:Skin / Q000098:blood supply / Q000378:metabolism*; D014661:Vasoconstriction; D044465:White People; D055815:Young Adult
chemical_list: D015415:Biomarkers; D017127:Glycation End Products, Advanced; D009824:Ointments