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 sta ble 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 conc entrations of the stable metabolites Tx-M and PGI-M did not differ bet ween 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 nonsm okers 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 househo lds (p = .53). In the 21 nonsmokers living with smokers, ETS exposure did not result in platelet activation as measured by either thromboxan e or prostacyclin release.