title: Correlation of endothelin 1 plasma levels with plasma antioxidant capacity in elderly patients treated for hypertension.
abstract: Experimental studies confirmed that reactive oxygen species increase endothelin-1 (ET-1) synthesis, and modulate ET-1 signaling pathway resulting in vasoconstriction and vascular remodeling. The aim of this study was to evaluate the relationship between plasma ET-1 concentration and antioxidant status in patients with essential hypertension and type 2 diabetes mellitus.
  
  
  METHODS
  78 hypertensive patients, 53.8% diabetic, mean age 72.1+/-7.07 were examined. The plasma concentration of glucose, creatinine, uric acid, bilirubin, cholesterol, insulin, HbA1c and ET-1 were measured. Antioxidant status was assessed by Ferric Reducing Ability of Plasma (FRAP), vitamin C concentration and erythrocyte superoxide dismutase (SOD) activity.
  
  
  RESULTS
  With diabetes ET-1 concentration was higher (1.35+/-0.51 vs 1.12+/-0.46 pg/mL, p=0.04). The negative correlations between ET-1 concentration and FRAP (r=-0.50, p<0.0001), vitamin C (r=-0.296, p=0.01) and SOD (r=-0.44, p=0.001) were found. Concentration of ET-1 correlated positively with SBP (r=0.33, p=0.005) but not with DBP. The relationship between DBP and ET-1 only in subjects with DBP>110 mm Hg and FRAP<0.40 mmol/L was found. In multiple regression analysis plasma ET-1 levels were associated independently with FRAP (beta=-0.583, p=0.003) and plasma vitamin C (beta=-0.407, p=0.04).
  
  
  CONCLUSIONS
  In hypertensive and diabetic patients higher plasma endothelin-1 level was independently associated with lower plasma antioxidant status measured by FRAP and decreased vitamin C concentration, which may be a result of increased oxidative stress in these diseases.
authors.affiliation: Department of Internal Medicine and Gerontology, Faculty of Medicine, Jagiellonian University Medical College, ul. Sniadeckich 10, 31-531 Krakow, Poland. anskal@su.krakow.pl
authors.forename: Anna B
authors.initials: AB
authors.lastname: Skalska
authors.forename: Agata
authors.initials: A
authors.lastname: Pietrzycka
authors.forename: Marek
authors.initials: M
authors.lastname: Stepniewski
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000494:pharmacology / Q000627:therapeutic use; D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000097:blood; D001794:Blood Pressure / Q000187:drug effects; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications; D019332:Endothelin-1 / Q000097:blood*; D004912:Erythrocytes / Q000187:drug effects / Q000201:enzymology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D011494:Protein Kinases / Q000097:blood; D012044:Regression Analysis; D013482:Superoxide Dismutase / Q000378:metabolism; D058570:TOR Serine-Threonine Kinases
chemical_list: D000959:Antihypertensive Agents; D000975:Antioxidants; D019332:Endothelin-1; D013482:Superoxide Dismutase; D011494:Protein Kinases; C546842:MTOR protein, human; D058570:TOR Serine-Threonine Kinases; D001205:Ascorbic Acid