Microalbuminuria and oxidative stress in essential hypertension.
OBJECTIVE
To assess the relationship between microalbuminuria and oxidative stress in mononuclear peripherals cells in essential hypertension.


METHODS
A total of 123 hypertensive patients in absence of antihypertensive treatment were included. A 24-h ambulatory blood pressure (BP) monitoring was performed using a Spacelabs 90207 monitor, and microalbuminuria was measured in 24-h urine collections. Oxidized/reduced glutathione ratio and the content of malondialdehide and damaged base 8-oxo-2'-deoxyguanosine in genomic and mitochondrial DNA were measured in peripheral mononuclear cells.


RESULTS
In the 29 (24%) microalbuminuric subjects, the amount of reduced glutathione was significantly lower and the ratio oxidized/reduced glutathione was significantly higher than in the normoalbuminuric subjects. In contrast, the simultaneous measurement of the levels of malondialdehide and 8-oxo-2'-deoxyguanosine from both genomic and mitochondrial DNA oxidation did not achieve statistical significance between the two groups. Subjects with the highest oxidized/reduced glutathione ratio tertile showed the highest urinary albumin excretion (UAE) (P = 0.04 for trend). In a stepwise multiple regression analysis, oxidized/reduced glutathione ratio was the main significant determinant of UAE accounting for the 9% of the variance when 24-h mean BP, age, sex, body mass index, glucose and total cholesterol were included in the model.


CONCLUSIONS
Oxidative stress seems to be a determinant of UAE independent of BP levels even in hypertensive subjects.
Giner
V
V
Department of Biochemistry of the Medical School, Hypertension Clinic, University of Valencia, Avda. Blasco Ibañez 17, 46010 Valencia, Spain.
Tormos
C
C
Chaves
F J
FJ
Sáez
G
G
Redón
J
J
D000328:Adult; D000419:Albuminuria / Q000209:etiology* / Q000235:genetics / Q000503:physiopathology; D018660:Blood Pressure Monitoring, Ambulatory / Q000379:methods; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications* / Q000235:genetics / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D012044:Regression Analysis