title: Homocysteine and red blood cell glutathione as indices for middle-aged untreated essential hypertension patients.
abstract: OBJECTIVE
  Intracellular glutathione in its reduced state is a principal cellular biomolecule with antioxidant activity. Glutathione and homocysteine metabolism are closely associated. As both oxidative stress and hyperhomocystinemia are associated with hypertension, we assessed the relationships between these variables.
  
  
  METHODS
  An observation-based case-control study, performed at a university teaching hospital.
  
  
  METHODS
  Middle-aged male patients with untreated uncomplicated essential hypertension (mean +/- standard deviation age 53.0 +/- 7.2 years, n = 48) before any treatment and controls with similar age distributions (age 51.6 +/- 5.5 years, n = 28) were evaluated.
  
  
  METHODS
  In all subjects, the plasma levels of homocysteine, lipids, creatinine, protein, and glucose were measured. Reduced and oxidized glutathione and folic acid were measured from red blood cells (RBC).
  
  
  RESULTS
  The hypertensive patients had decreased levels of red blood cell reduced glutathione (RBC-GSH) and increased levels of oxidized glutathione, which resulted in elevated ratio of oxidized/reduced glutathione as compared to controls (P < 0.001). Plasma homocysteine levels were significantly higher in the hypertensive patients versus the age-matched controls (P < 0.004). In the hypertensive patients, RBC-GSH correlated inversely with systolic blood pressure, serum creatinine, protein and RBC folic acid. No correlation was detected between RBC-GSH and homocysteine. In the controls, RBC-GSH correlated inversely with homocysteine, RBC folic acid and creatinine. According to multiple regression, in the hypertensive patients RBC-GSH was related to systolic blood pressure, hemoglobin, plasma homocysteine, creatinine and protein. Such a relationship was not detected for the controls.
  
  
  CONCLUSIONS
  In untreated hypertensive patients both homocysteine and systolic blood pressure are associated with intracellular oxidative stress as determined by RBC-GSH.
authors.affiliation: Department of Cardiology, University of Tartu, Estonia. Piibe.Muda@klinikum.ee
authors.forename: Piibe
authors.initials: P
authors.lastname: Muda
authors.forename: Priit
authors.initials: P
authors.lastname: Kampus
authors.forename: Mihkel
authors.initials: M
authors.lastname: Zilmer
authors.forename: Kersti
authors.initials: K
authors.lastname: Zilmer
authors.forename: Ceslava
authors.initials: C
authors.lastname: Kairane
authors.forename: Tiina
authors.initials: T
authors.lastname: Ristimäe
authors.forename: Krista
authors.initials: K
authors.lastname: Fischer
authors.forename: Rein
authors.initials: R
authors.lastname: Teesalu
mesh_terms: D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure / Q000502:physiology; D001798:Blood Proteins / Q000378:metabolism; D015992:Body Mass Index; D016022:Case-Control Studies; D003404:Creatinine / Q000097:blood; D004912:Erythrocytes / Q000737:chemistry*; D004957:Estonia; D005492:Folic Acid / Q000097:blood; D005978:Glutathione / Q000097:blood*; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D006973:Hypertension / Q000097:blood*; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology; D013223:Statistics as Topic; D013599:Systole / Q000502:physiology
chemical_list: D015415:Biomarkers; D001798:Blood Proteins; D006710:Homocysteine; D005492:Folic Acid; D003404:Creatinine; D005978:Glutathione