title: A study of gender-based cytochrome P4501A2 variability: a possible mechanism for the male excess of bladder cancer.
abstract: One hypothesis for the well known gender difference in bladder cancer risk is that males and females metabolize carcinogens differently. The caffeine breath test (CBT) was performed on a group of healthy men and women to determine whether there was a gender difference in P4501A2 activity. Results consistent with previous data suggest an elevation of CBT in men were observed, although this increase was not statistically significant. Among women, however, there was a significant difference between nulliparous and parous women(P = 0.03). Parous women had CBT values similar to men, whereas the results of women who had never given birth were lower. Confirming earlier studies, women taking oral contraceptives had low CBT values. Our data suggest an effect of recent caffeine consumption, with heavy coffee drinkers having higher rates of caffeine clearance. Adjustment for other weak effects, such as age, exposure to environment cigarette smoke, history of smoking, recent meat and cruciferous vegetable consumption, and use of alcohol or other medications, did not alter these findings. The finding of a difference between parous and nulliparous women requires further study.
authors.affiliation: Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: E P
authors.initials: EP
authors.lastname: Horn
authors.forename: M A
authors.initials: MA
authors.lastname: Tucker
authors.forename: G
authors.initials: G
authors.lastname: Lambert
authors.forename: D
authors.initials: D
authors.lastname: Silverman
authors.forename: D
authors.initials: D
authors.lastname: Zametkin
authors.forename: R
authors.initials: R
authors.lastname: Sinha
authors.forename: T
authors.initials: T
authors.lastname: Hartge
authors.forename: M T
authors.initials: MT
authors.lastname: Landi
authors.forename: N E
authors.initials: NE
authors.lastname: Caporaso
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000009:adverse effects; D001944:Breath Tests; D002110:Caffeine; D019388:Cytochrome P-450 CYP1A2; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004032:Diet / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010088:Oxidoreductases / Q000378:metabolism*; D010298:Parity; D012044:Regression Analysis; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects; D001749:Urinary Bladder Neoplasms / Q000201:enzymology
chemical_list: D002110:Caffeine; D003577:Cytochrome P-450 Enzyme System; D010088:Oxidoreductases; D019388:Cytochrome P-450 CYP1A2