title: Vitamin D status is associated with skin autofluorescence in patients with type 2 diabetes mellitus: a preliminary report.
abstract: BACKGROUND
  Skin autofluorescence is a non-invasive measurement of advanced glycation end products (AGE), which are suggested to be one of the major agents in the pathogenesis and progression of diabetes related cardiovascular complications. Recently, low vitamin D status has been linked to the progression of type 2 diabetes mellitus (T2DM) and cardiovascular disease. The aim of this study is to investigate the association between vitamin D status and skin autofluorescence in patients with T2DM.
  
  
  METHODS
  In this preliminary report skin autofluorescence was measured non-invasively with an AGE-reader in 245 patients with T2DM treated with lifestyle advice, metformin and/or sulphonylurea-derivatives. All patients were randomly assigned to receive either vitamin D 50,000 IU/month or placebo for 6 months.
  
  
  RESULTS
  Skin autofluorescence was significantly higher in patients with a serum 25(OH)D < 50 nmol/l compared to patients with a serum 25(OH)D > 75 nmol/l (2.81 versus 2.41; p < 0.001). Mean serum 25(OH)D was 60.3 ± 23.4 nmol/l and was independently associated with skin autofluorescence (β -0.006; p < 0.001). Mean vitamin D increased from 60.8 to 103.6 nmol/l in the intervention group, however no effect was seen on accumulation of skin AGEs after 6 months compared to placebo.
  
  
  CONCLUSIONS
  Vitamin D status is independently associated with skin auto fluorescence in patients with well-controlled T2DM. No effect was seen on the amount of skin AGEs after a short period of 6 months vitamin D supplementation. Further research with longer follow-up and measurement of circulating advanced glycation end products is needed to elucidate the causality of the association.
authors.affiliation: Department of Internal Medicine, Medical Centre Alkmaar, PO Box 7057, Wilhelminalaan 12, 1815 JD, Alkmaar, The Netherlands. y.h.m.krul-poel@mca.nl.
authors.forename: Y H M
authors.initials: YH
authors.lastname: Krul-Poel
authors.affiliation: Department of Internal Medicine, Medical Centre Alkmaar, PO Box 7057, Wilhelminalaan 12, 1815 JD, Alkmaar, The Netherlands. r.agca@reade.nl.
authors.forename: R
authors.initials: R
authors.lastname: Agca
authors.affiliation: Department of Internal Medicine/Endocrinology, VU University Medical Centre, Amsterdam, The Netherlands. p.lips@vumc.nl.
authors.forename: P
authors.initials: P
authors.lastname: Lips
authors.affiliation: Department of General Practice, DIAZON, Alkmaar, The Netherlands. wijland@deleonnet.nl.
authors.forename: H
authors.initials: H
authors.lastname: van Wijland
authors.affiliation: Department of Internal Medicine, Medical Centre Alkmaar, PO Box 7057, Wilhelminalaan 12, 1815 JD, Alkmaar, The Netherlands. frank.stam@mca.nl.
authors.forename: F
authors.initials: F
authors.lastname: Stam
authors.affiliation: Department of Internal Medicine, Medical Centre Alkmaar, PO Box 7057, Wilhelminalaan 12, 1815 JD, Alkmaar, The Netherlands. s.simsek@mca.nl.|Department of Internal Medicine/Endocrinology, VU University Medical Centre, Amsterdam, The Netherlands. s.simsek@mca.nl.
authors.forename: S
authors.initials: S
authors.lastname: Simsek
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D048909:Diabetes Complications / Q000150:complications; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000378:metabolism* / Q000628:therapy; D004359:Drug Therapy, Combination; D005260:Female; D017127:Glycation End Products, Advanced / Q000378:metabolism*; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D008137:Longitudinal Studies; D008297:Male; D008687:Metformin / Q000627:therapeutic use; D008875:Middle Aged; D061848:Optical Imaging; D040242:Risk Reduction Behavior; D012867:Skin / Q000378:metabolism*; D013453:Sulfonylurea Compounds / Q000627:therapeutic use; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood / Q000627:therapeutic use*; D014808:Vitamin D Deficiency / Q000150:complications / Q000188:drug therapy* / Q000378:metabolism; D014815:Vitamins / Q000627:therapeutic use*
chemical_list: D017127:Glycation End Products, Advanced; D007004:Hypoglycemic Agents; D013453:Sulfonylurea Compounds; D014815:Vitamins; D014807:Vitamin D; D008687:Metformin; C104450:25-hydroxyvitamin D