title: Advanced glycation end products in the skin are enhanced in COPD.
abstract: BACKGROUND
  Cigarette smoking is the main cause of chronic obstructive pulmonary disease (COPD) inducing oxidative stress and local tissue injury, resulting in pulmonary inflammation. Advanced glycation end products (AGEs) are produced by glycation and oxidation processes and their formation is accelerated in inflammatory conditions. In this study we assessed whether AGE accumulation in the skin is elevated in COPD and associates with disease severity.
  
  
  METHODS
  202 mild-to-very-severe COPD patients and 83 old (40-75 years) and 110 young (18-40 years) healthy smokers and never-smokers were included. AGEs were measured by skin autofluorescence (SAF). Demographic variables, smoking habits, co-morbidities and lung function values were obtained.
  
  
  RESULTS
  COPD patients (FEV₁=55% predicted) had significantly higher SAF values than old and young healthy controls: 2.5 vs. 1.8 and 1.2 (arbitrary units, p<0.05). No differences in SAF values were found between GOLD stages I-IV (2.4, 2.3, 2.5, 2.5 respectively). Lower function (FEV₁/FVC, MEF₅₀/FVC, RV/TLC) and higher number of packyears were significantly associated with SAF (p<0.05).
  
  
  CONCLUSIONS
  SAF is increased in mild-to-very severe COPD patients compared with healthy controls. Interestingly, SAF was not associated with disease severity as values were comparable between different GOLD stages (stage I-IV) of COPD. This may suggest that AGEs play a role in the induction phase of COPD in susceptible smokers. Future studies should further investigate the mechanisms underlying AGEs formation and accumulation in COPD.
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Pulmonary Diseases, Groningen, the Netherlands; University of Groningen, University Medical Center Groningen, GRIAC research institute, Groningen, the Netherlands.
authors.forename: Susan J M
authors.initials: SJ
authors.lastname: Hoonhorst
authors.affiliation: University Medical Center Utrecht, Department of Respiratory Medicine, Utrecht, the Netherlands.
authors.forename: Adèle T
authors.initials: AT
authors.lastname: Lo Tam Loi
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Pulmonary Diseases, Groningen, the Netherlands; University of Groningen, University Medical Center Groningen, GRIAC research institute, Groningen, the Netherlands.
authors.forename: Jorine E
authors.initials: JE
authors.lastname: Hartman
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Pulmonary Diseases, Groningen, the Netherlands; University of Groningen, University Medical Center Groningen, GRIAC research institute, Groningen, the Netherlands.
authors.forename: Eef D
authors.initials: ED
authors.lastname: Telenga
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Pulmonary Diseases, Groningen, the Netherlands; University of Groningen, University Medical Center Groningen, GRIAC research institute, Groningen, the Netherlands.
authors.forename: Maarten
authors.initials: M
authors.lastname: van den Berge
authors.affiliation: University Medical Center Utrecht, Department of Respiratory Medicine, Utrecht, the Netherlands.
authors.forename: Leo
authors.initials: L
authors.lastname: Koenderman
authors.affiliation: University Medical Center Utrecht, Department of Respiratory Medicine, Utrecht, the Netherlands.
authors.forename: Jan Willem J
authors.initials: JW
authors.lastname: Lammers
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Pulmonary Diseases, Groningen, the Netherlands; University of Groningen, University Medical Center Groningen, Department of Epidemiology, Groningen, the Netherlands.
authors.forename: H Marike
authors.initials: HM
authors.lastname: Boezen
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Pulmonary Diseases, Groningen, the Netherlands; University of Groningen, University Medical Center Groningen, GRIAC research institute, Groningen, the Netherlands.
authors.forename: Dirkje S
authors.initials: DS
authors.lastname: Postma
authors.affiliation: University of Groningen, University Medical Center Groningen, Department of Pulmonary Diseases, Groningen, the Netherlands; University of Groningen, University Medical Center Groningen, GRIAC research institute, Groningen, the Netherlands. Electronic address: n.h.t.ten.hacken@umcg.nl.
authors.forename: Nick H T
authors.initials: NH
authors.lastname: Ten Hacken
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D003430:Cross-Sectional Studies; D005260:Female; D017127:Glycation End Products, Advanced / Q000378:metabolism*; D006801:Humans; D008168:Lung / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D018384:Oxidative Stress; D029424:Pulmonary Disease, Chronic Obstructive / Q000378:metabolism* / Q000503:physiopathology; D012720:Severity of Illness Index; D012867:Skin / Q000378:metabolism*; D012907:Smoking / Q000009:adverse effects / Q000378:metabolism; D015854:Up-Regulation; D055815:Young Adult
chemical_list: D015415:Biomarkers; D017127:Glycation End Products, Advanced
keywords: Advanced glycation end products; COPD; Oxidative stress; Smoking