Homocysteine and red blood cell glutathione as indices for middle-aged untreated essential hypertension patients.
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.
Muda
Piibe
P
Department of Cardiology, University of Tartu, Estonia. Piibe.Muda@klinikum.ee
Kampus
Priit
P
Zilmer
Mihkel
M
Zilmer
Kersti
K
Kairane
Ceslava
C
Ristimäe
Tiina
T
Fischer
Krista
K
Teesalu
Rein
R
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
D015415:Biomarkers; D001798:Blood Proteins; D006710:Homocysteine; D005492:Folic Acid; D003404:Creatinine; D005978:Glutathione