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Br J Clin Pharmacol. 2001 Nov;52(5):601-4.

Variability of cytochrome P450 1A2 activity over time in young and elderly healthy volunteers.

Author information

1
Department of Pharmacology, Saint Antoine Paris-VI University Hospital, Paris, France. Tabassome.Simon@chusa.jussieu.fr

Abstract

AIMS:

To assess the age-associated changes over time of plasma paraxanthine/caffeine (PAX/CAF) ratios used as a probe for CYP1A2 activity.

METHODS:

Intraindividual and interindividual variabilities in PAX/CAF ratio were compared by phenotyping with caffeine, 16 young and 16 elderly healthy subjects on five occasions.

RESULTS:

PAX/CAF ratio variability was comparable regardless of age (intraindividual CV: 17.6 +/- 6% and 16.2 +/- 5.9%, interindividual CV: 48.1 +/- 2.9% and 42.7 +/- 3.6% in young and elderly, respectively). The PAX/CAF ratio was lower in elderly than in young subjects (95% CI for the difference: 0.004, 0.32) but the difference was not significant in nonsmokers compared separately.

CONCLUSIONS:

The variability over time of the PAX/CAF ratio is not influenced by age.

PMID:
11736870
PMCID:
PMC2014598
[Indexed for MEDLINE]
Free PMC Article

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