Urinary excretion of the pyridinium cross-links of collagen in systemic lupus erythematosus.
The aim of this study was to measure the urinary excretion of the pyridinium cross-links of collagen and to determine their usefulness as markers of reduced bone mineral density in systemic lupus erythematosus (SLE). All female SLE patients managed at a single centre were invited to participate in a cross-sectional study of urinary pyridinium cross-links excretion (HPLC), bone mineral density (DXA), and SLE-related variables. Ninety-one women with SLE were studied, 35 of whom were postmenopausal. Pyridinoline/Creatinine (Pyd/Cr) and deoxypyridinoline/Cr (Dpd/Cr) levels in postmenopausal women were significantly increased compared with premenopausal values (p = 0.010 and p = 0.004, respectively). Univariate linear regression analysis revealed a significant association of Dpd/Cr with reduced femoral neck and lumbar spine BMD (p = 0.001, p<0.001), and of Pyd/Cr with reduced femoral neck BMD (p = 0.020). In addition, the association of Pyd/Cr with reduced lumbar spine BMD approached significance (p = 0.055). Stepwise multiple linear regression analysis adjusting for other variables confirmed a significant association of Dpd/Cr with reduced lumbar spine BMD (p = 0.006), and a significant association of both Pyd/Cr and Dpd/Cr with postmenopausal status (p = 0.003, p<0.001). It was concluded that in this SLE population, the urinary excretion of Dpd/Cr was a useful marker of reduced BMD at the lumbar spine. Menopausal status was a major predictor of cross-links excretion in SLE.
Department of Rheumatology, Monash Medical Centre, Melbourne, Victoria, Australia.
Y
Y
Kipen
R
R
Will
B J
BJ
Strauss
E F
EF
Morand
D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D000596:Amino Acids / Q000652:urine; D015415:Biomarkers / Q000652:urine; D015519:Bone Density; D002851:Chromatography, High Pressure Liquid; D003094:Collagen / Q000652:urine*; D024042:Collagen Type I; D003404:Creatinine / Q000652:urine; D003430:Cross-Sectional Studies; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging / Q000378:metabolism; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000378:metabolism; D008180:Lupus Erythematosus, Systemic / Q000000981:diagnostic imaging / Q000652:urine*; D008593:Menopause / Q000652:urine; D010455:Peptides / Q000652:urine*
D000596:Amino Acids; D015415:Biomarkers; D024042:Collagen Type I; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; C015484:pyridinoline; C036020:deoxypyridinoline; D003094:Collagen; D003404:Creatinine