Estimated read time: 2-3 minutes
This archived news story is available only for your personal, non-commercial use. Information in the story may be outdated or superseded by additional information. Reading or replaying the story in its archived form does not constitute a republication of the story.
Gender differences in lung cancer may be related to the influence of sex hormones on nicotine metabolism in women.
According to investigators at the University of California, "Several studies have reported that female smokers have a higher risk of lung cancer than male smokers. This could be related to sex differences in nicotine metabolism and related smoking behavior. This study tested the hypothesis that women metabolize nicotine more rapidly than men and that, among women, oral contraceptive users metabolize nicotine more rapidly than nonusers of oral contraceptives."
"Two hundred seventy-eight healthy volunteers who were twins and 16 who were siblings of twins, recruited from the Northern California Twin Registry, received an infusion of deuterium-labeled nicotine and cotinine with frequent blood sampling," explained N.L. Benowitz and colleagues. "The plasma clearances of nicotine and cotinine, the clearance of nicotine to cotinine (an index of cytochrome P450 [CYP] 2A6 activity), and the ratio of trans-3'-hydroxycotinine to cotinine (another indicator of CYP2A6 activity) were measured."
The authors recorded, "The clearances of nicotine and cotinine, the clearance of nicotine to cotinine, and the trans-3'-hydroxycotinine/cotinine ratio were significantly higher in women than in men (nicotine clearance, 15.6±4.3 mL/min-1/kg-1 in men versus 18.8±6.6 mL/min-1/kg-1 in women; p-1/kg-1 in women taking oral contraceptives versus 17.6±6.1 mL/min-1/kg-1 in those who were not; p<.05)."
"Women who were menopausal or postmenopausal were not different from men," they noted. "Among oral contraceptive users, nicotine metabolism was accelerated among those taking combined and estrogen-only contraceptives but not progesterone-only contraceptives."
The researchers concluded, "Sex hormones influence nicotine metabolism. Nicotine and cotinine metabolism is faster in women than in men and is faster in women taking oral contraceptives compared with those who are not. Accelerated nicotine metabolism appears to be a result of estrogen. Sex-related differences in nicotine clearance could affect smoking behaviors, as well as response to nicotine medications, and could be a marker for altered metabolism of nicotine-derived carcinogens."
Benowitz and colleagues published their study in Clinical Pharmacology & Therapeutics (Female sex and oral contraceptive use accelerate nicotine metabolism. Clin Pharmacol Ther, 2006;79(5):480-488).
For more information, contact N.L. Benowitz, Division of Clinical Pharmacology and Experimental Therapeutics, University of California, San Francisco, Box 1220, San Francisco, CA 94143-1220, USA; E-mail: NBenowitz@MedSFGH.ucsf.edu.
Publisher contact information for the journal Clinical Pharmacology & Therapeutics is: Mosby, Inc., 11830 Westline Industrial Drive, St. Louis, MO 63146-3318, USA.
Keywords: San Francisco, California, United States, Lung Cancer, Lung Carcinoma, Lung Cancer Risk, Smoking, Nicotine Metabolism, Gender Differences, Oral Contraceptive, Sex Hormones, Women's Health. This article was prepared by Biotech Week editors from staff and other reports. Copyright 2006, Biotech Week via NewsRx.com.
To see more of the NewsRx.com, or to subscribe, go to http://www.newsrx.com.
© 2004 NewsRx.com. All Rights Reserved.;;©Copyright 2006, Biotech Week via NewsRx.com
