Urinary prostacyclin in nonsmokers living with smokers

This study tested the hypothesis that environmental tobacco smoke (ETS) exposure increases platelet activation. The concentration of the stable urinary metabolites of thromboxane (Tx-M) and prostacyclin (PGI-M) was measured in 3 groups of subjects: 27 nonsmokers who did not live with a smoker, 21 nonsmokers who lived with at least 1 smoker, and 10 cigarette smokers who served as a positive control group. Urinary concentrations of the stable metabolites Tx-M and PGI-M did not differ between the nonsmokers living with at least one smoker and the nonsmokers not living with a smoker (p = .39 for Tx-M; p = .42 for PGI-M). There was a statistically significant increase in the urinary concentration of PGI-M in the cigarette smokers when compared with either the nonsmokers living with at least one smoker (p < .05) or the nonsmokers not living with a smoker (p < .05). There was no significant difference in Tx-M excretion in the cigarette smokers relative to either nonsmokers living with a smoker (p = .99) or to nonsmokers in nonsmoking households (p = .53). In the 21 nonsmokers living with smokers, ETS exposure did not result in platelet activation as measured by either thromboxane or prostacyclin release.