title: Urinary glycosylated, free and total pyridinoline and free and total deoxypyridinoline in diabetes mellitus.
abstract: OBJECTIVE
  Published data on bone metabolism in diabetes mellitus are conflicting. We have measured pyridinium crosslinks, biochemical markers of bone resorption, in order to evaluate bone resorption in diabetes mellitus. We also wished to investigate whether, as a consequence of chronic hyperglycaemia, pyridinoline is glycosylated to a greater extent in patients with diabetes mellitus.
  
  
  METHODS
  This cross sectional study included 142 patients (64 males, 78 females) with insulin dependent and non-insulin dependent diabetes mellitus (IDDM and NIDDM). These patients were compared to a healthy control group of 99 individuals (39 males and 60 females).
  
  
  METHODS
  Pyridinium crosslinks, glycosylated, free and total pyridinoline (gPYD, fPYD, tPYD) and free and total deoxypridinoline (fDPD, tDPD) were measured in a spot urine sample by high performance liquid chromatography (HPLC). Urinary creatinine, albumin and glucose were also measured.
  
  
  RESULTS
  In the diabetic group, values of urinary gPYD and tDYD were significantly lower than in controls. gPYD excretion was lowest in patients with severe glycosuria. Free pyridinium crosslinks, both fPYD and fDPD, were excreted to a significantly lower extent. The molar ratio of tPYD to tDPD was significantly increased in diabetes mellitus.
  
  
  CONCLUSIONS
  Decreased excretion of tDPD suggests low bone resorption in IDDM and NIDDM. Pyridinoline is not glycosylated to a greater extent in diabetes mellitus and tends to be decreased in proportion to the degree of glycosuria. Excretion of gPYD, fPYD and fDPD is depressed in severe glycosuria. Diminshed degradation to the final products, fPYD and fDPD, might represent increased resistance to enzymatic activity or diminished enzymatic activity. The increased molar ratio tPYD/tDPD in urine suggests an increased ratio in bone collagen in diabetes mellitus.
authors.affiliation: Laboratory Group, University of Heidelberg, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Cloos
authors.forename: P
authors.initials: P
authors.lastname: Wahl
authors.forename: C
authors.initials: C
authors.lastname: Hasslacher
authors.forename: L
authors.initials: L
authors.lastname: Traber
authors.forename: M
authors.initials: M
authors.lastname: Kistner
authors.forename: K
authors.initials: K
authors.lastname: Jurkuhn
authors.forename: H
authors.initials: H
authors.lastname: Schmidt-Gayk
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000596:Amino Acids / Q000652:urine*; D015415:Biomarkers / Q000652:urine; D001862:Bone Resorption / Q000652:urine*; D002851:Chromatography, High Pressure Liquid; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000652:urine*; D003922:Diabetes Mellitus, Type 1 / Q000652:urine; D003924:Diabetes Mellitus, Type 2 / Q000652:urine; D005260:Female; D006031:Glycosylation; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D000596:Amino Acids; D015415:Biomarkers; C015484:pyridinoline; C036020:deoxypyridinoline