Environmental @entity286 smoke (ETS) is suspected to be an important risk factor for @entity2488 . In order to test the effect of ETS, we measured expiratory flow rates and urine @entity4874 excretion (UCE) within a narrow time window in two consecutive years. Maternal smoking habits and medical history were ascertained by standardized questionnaires. The percentage ratio of the amplitude over the mean (AVAM) of the diurnal peak flow rates of @entity1 (complete values from at least five consecutive days) was calculated as an indicator of bronchial responsiveness. The association of UCE and log10AVAM was analyzed by multiple linear regression. Complete data were available for a sample of 417 @entity1 . The median of UCE in @entity1 of parents who smoked (3.2 ng/mg and 2.9 ng/mg @entity1011 , Surveys 1 and 2, respectively) was higher than the median in @entity1 of nonsmoking parents (0 ng/mg in both surveys). With increasing UCE the log10AVAM rose in the first and second surveys, as well as in the longitudinal analysis (p = 0.003). This association, however, showed up only in @entity1 (p = 0.0001) and not in @entity1 (p = 0.31). Our data suggest that there is a need both for further analysis of the gender difference and for more support of strategies against passive smoking as far as @entity1 are concerned, since airway hyperresponsiveness is a risk factor for chronic @entity73 .

XXXX excretion as a predictor of peak flow variability.

@entity1 :: ('9606', 'Species') :: ['children', 'girls', 'boys'] @entity286 :: ('4097', 'Species') :: ['tobacco'] @entity2488 :: ('MESH:D001982', 'Disease') :: ['bronchial hyperresponsiveness'] @entity73 :: ('MESH:D003072', 'Disease') :: ['airway impairment'] @entity4874 :: ('MESH:D003367', 'Chemical') :: ['cotinine'] @entity1011 :: ('MESH:D003404', 'Chemical') :: ['creatinine']
@entity4874 :: (MESH:D003367,Chemical) :: ['Cotinine']
