title: Advanced glycation end product associated skin autofluorescence: a mirror of vascular function?
abstract: Advanced glycation end products (AGEs) seem to be involved in aging as well as in the development of cardiovascular diseases. During aging, AGEs accumulate in extracellular matrix proteins like collagen and contribute to vessel stiffness. Whether non-invasive measurement of AGE accumulation in the skin may reflect vessel function and vessel protein modification is unknown. Herein we set out to analyze the AGE-modifications in the collagens extracted from residual bypass graft material, the skin autofluorescence reflecting the accumulation of AGEs in the body as well as the pulse wave velocity reflecting vessel stiffness. Collagen types I and III (pepsin digestible collagen fraction) were isolated from the veins of 52 patients by proteolysis. The residual collagen fraction was further extracted by collagenase digestion. Collagen was quantified by hydroxyproline assay and AGEs by the AGE intrinsic fluorescence. Skin autofluorescence was measured with an autofluorescence reader; pulse wave velocity with the VICORDER. The collagen AGE autofluorescence in patient vein graft material increased with patient age. The pepsin digestible collagen fraction was significantly less modified in comparison to the collagenase digestible fraction. Decreasing amounts of extracted collagenase digestible collagen correspond with increasing AGE autofluorescence. Skin autofluorescence and vessel stiffness were significantly linked to the AGE autofluorescence of the collagenase digestible collagen fraction from graft material. In conclusion we have found that skin autofluorescence and pulse wave velocity as non-invasive parameters significantly correlate with the AGE contained in graft material and therefore are strong predictors of vessel AGE modifications in patients with coronary heart disease. Whether the analysis of the skin autofluorescence leads to an improvement of the risk stratification in patients suffering from cardiovascular disease has to be further tested.
authors.affiliation: Department of Cardiothoracic Surgery, Martin-Luther-University, Halle (Saale), Germany. britt.hofmann@medizin.uni-halle.de
authors.forename: Britt
authors.initials: B
authors.lastname: Hofmann
authors.forename: Anne-Catrin
authors.initials: AC
authors.lastname: Adam
authors.forename: Kathleen
authors.initials: K
authors.lastname: Jacobs
authors.forename: Marcus
authors.initials: M
authors.lastname: Riemer
authors.forename: Christian
authors.initials: C
authors.lastname: Erbs
authors.forename: Hasan
authors.initials: H
authors.lastname: Bushnaq
authors.forename: Andreas
authors.initials: A
authors.lastname: Simm
authors.forename: Rolf-Edgar
authors.initials: RE
authors.lastname: Silber
authors.forename: Alexander Navarrete
authors.initials: AN
authors.lastname: Santos
mesh_terms: D000368:Aged; D000375:Aging / Q000378:metabolism / Q000502:physiology; D001783:Blood Flow Velocity / Q000502:physiology; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D017536:Carotid Artery, Common / Q000503:physiopathology; D024042:Collagen Type I / Q000378:metabolism; D024061:Collagen Type III / Q000378:metabolism; D003327:Coronary Disease / Q000378:metabolism* / Q000503:physiopathology; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism; D005263:Femoral Artery / Q000503:physiopathology; D005453:Fluorescence; D006442:Glycated Hemoglobin / Q000378:metabolism; D017127:Glycation End Products, Advanced / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012501:Saphenous Vein / Q000378:metabolism / Q000637:transplantation; D012867:Skin / Q000098:blood supply* / Q000378:metabolism; D012907:Smoking / Q000378:metabolism; D059289:Vascular Stiffness / Q000502:physiology
chemical_list: D001786:Blood Glucose; D024042:Collagen Type I; D024061:Collagen Type III; D006442:Glycated Hemoglobin; D017127:Glycation End Products, Advanced; C517652:hemoglobin A1c protein, human