title: Evaluation of urinary biomarkers of oxidative/nitrosative stress in adolescents and adults with Down syndrome.
abstract: Urinary biomarkers of oxidative stress have been little studied in adults with Down syndrome (DS), usually no more than two biomarkers have been measured in the population studied and controversial results are reported in literature. Thus, we aimed to assess a set of oxidative and nitrosative stress biomarkers in urine samples of adolescents and adults with DS, with and without hypothyroidism, which comprise: 8-hydroxy-2'-deoxyguanosine (8-OHdG), isoprostane 15-F(2t)-IsoP, thiobarbituric acid-reacting substances (TBARS), advanced glycation end products (AGEs), dityrosine (diTyr), hydrogen peroxide (H(2)O(2)) and nitrite/nitrate (NOx). Fluorimetric and spectrophotometric assays were performed in DS (n=78), some of them taking levothyroxine for hypothyroidism (n=24), and in their healthy age-matched controls (n=65). We found that levels of AGEs, diTyr, H(2)O(2) and NOx are increased in DS patients in any or in all age groups, whereas Cr levels were lower in DS than in controls in all age groups. Besides, correlations with age in DS were positive for diTyr and negative for Cr, TBARS, 15-F(2t)-IsoP and NOx. We also found lower levels of Cr from 15 to 19years, higher levels of TBARS and AGEs from 20 to 40years and higher levels of diTyr from 15 to 40years in DS patients receiving levothyroxine than in DS without hypothyroidism diagnosed. We conclude that AGEs, diTyr, H(2)O(2) and NOx could be used as oxidative stress biomarkers in DS in contrast to 8-OHdG, 15-F(2t)-IsoP and TBARS, at least with the methods used. However, renal impairment could occur in DS and Cr adjustment may bias the results, particularly in hypothyroid patients.
authors: Department of Cellular and Molecular Medicine, Centre for Biological Research-Spanish National Research Council (CIB-CSIC), C/ Ramiro de Maeztu, 9. E-28040 Madrid, Spain. carloscamposvaquero@gmail.com
authors: Carlos
authors: C
authors: Campos
authors: Rodrigo
authors: R
authors: Guzmán
authors: Encarnación
authors: E
authors: López-Fernández
authors: Angela
authors: A
authors: Casado
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000652:urine*; D016022:Case-Control Studies; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000652:urine; D004314:Down Syndrome / Q000150:complications / Q000378:metabolism / Q000652:urine*; D017127:Glycation End Products, Advanced / Q000378:metabolism; D006801:Humans; D007037:Hypothyroidism / Q000150:complications; D015227:Lipid Peroxidation; D008875:Middle Aged; D017672:Nitrogen Compounds / Q000378:metabolism*; D018384:Oxidative Stress; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D055815:Young Adult
chemical_list: D015415:Biomarkers; D017127:Glycation End Products, Advanced; D017672:Nitrogen Compounds; D017392:Thiobarbituric Acid Reactive Substances; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine