The urinary metabolites "
prostaglandin E2 metabolite" (
PGE-M) and (Z)-7-[1R,2R,3R,5S)-3,5-dihydroxy-2-[(E,3S)-3-hydroxyoct-1-enyl]cyclopentyl]hept-5-enoic
acid (8-iso-PGF2α) are
biomarkers of
inflammation and oxidative damage, respectively, and are elevated in cigarette smokers. Relatively little is known about the effects of smoking cessation on these
biomarkers. To investigate this, current cigarette smokers interested in quitting were recruited and invited to participate in a smoking cessation study where
varenicline (
Chantix) and brief supportive behavioral counseling were offered at each visit after baseline. Subjects returned to the clinic during the 12 week treatment phase for 9 visits post cessation on days 3, 7, 14, 21, 28, 42, 56, 70 and 84. Urine samples were collected at each visit and analyzed by liquid chromatography-tandem mass spectrometry for
PGE-M, 8-iso-PGF2α, and
cotinine.
Cotinine values demonstrated that 15 of 38 subjects quit smoking for the entire 84 day period. Significant decreases in mean levels of
PGE-M and 8-iso-PGF2α per milligram
creatinine were observed in these subjects, by 44% (p = 0.0014) and 27% (p<0.001), respectively. The results of this study demonstrate that cessation of smoking for 84 days results in modest but significant declines in urinary
PGE-M and 8-iso-PGF2α indicating reductions in systemic
inflammation and oxidative damage. Given that levels were only modestly decreased, these markers are not specific to tobacco-
smoke exposure. The modest declines in these
biomarkers should be considered when planning studies with ex-smokers. There is a "hangover" from smoking that lasts at least 3 months.