Selenium and oxygen-metabolizing enzymes in elderly community residents: a pilot epidemiological study.
OBJECTIVE
To investigate the relationship of selenium and oxygen-deactivating enzymes with age in the elderly.


METHODS
The study sample consisted of volunteers recruited from the PAQUID study. This study is conducted in a representative sample of non-institutionalized individuals aged > or = 65 years living in Southwestern France; its main objective is to study longitudinally the incidence and risk factors of dementia.


METHODS
Plasma and erythrocyte selenium and activities of oxygen metabolizing enzymes in erythrocytes (GSH-Px, CuZn-SOD, and GSSG-RD) were measured in 239 volunteers (108 males and 131 females; mean age 73.7 years).


RESULTS
Plasma selenium (PSe) decreased significantly with age; a similar but non-significant trend was found for erythrocyte selenium (ESe). None of the enzyme activities showed a clear relationship with age. Women had significantly higher GSH-Px activities than men. For PSe levels lower than 77 ng/mL, there was a strong correlation between PSe and GSH-Px; above this value, the correlation decreased, suggesting that the selenium requirement for GSH-Px production had been satisfied. In this sample, CuZn-SOD was correlated negatively with GSH-Px (r = -0.18; P < or = 0.01) and positively with GSSG-RD (r = +0.20; P < or = 0.01).


CONCLUSIONS
In individuals aged > or = 65 years, we found that blood selenium levels were negatively correlated with age. Our analysis of the relationship between selenium and GSH-Px activity suggests that low selenium values are associated with decreased GSH-Px activity.
Berr
C
C
INSERM U360, Villejuif, France.
Nicole
A
A
Godin
J
J
Ceballos-Picot
I
I
Thevenin
M
M
Dartigues
J F
JF
Alperovitch
A
A
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism*; D004812:Epidemiologic Methods; D005260:Female; D005978:Glutathione / Q000378:metabolism*; D005980:Glutathione Reductase / Q000378:metabolism*; D006801:Humans; D008297:Male; D010865:Pilot Projects; D012643:Selenium / Q000097:blood*; D012737:Sex Factors; D013482:Superoxide Dismutase / Q000378:metabolism*
D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005978:Glutathione; D012643:Selenium