Is the socioeconomic gap in childhood exposure to secondhand smoke widening or narrowing?

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A longitudinal study of environmental tobacco smoke exposure in children: Parental self reports versus age dependent biomarkers

<p>Abstract</p> <p>Background</p> <p>Awareness of the negative effects of smoking on children's health prompted a decrease in the self-reporting of parental tobacco use in periodic surveys from most industrialized countries. Our aim is to assess changes between ETS exposure at the end of pregnancy and at 4 years of age determined by the parents' self-report and measurement of cotinine in age related biological matrices.</p> <p>Methods</p> <p>The prospective birth cohort included 487 infants from Barcelona city (Spain). Mothers were asked about maternal and household smoking habit. Cord serum and children's urinary cotinine were analyzed in duplicate using a double antibody radioimmunoassay.</p> <p>Results</p> <p>At 4 years of age, the median urinary cotinine level in children increased 1.4 or 3.5 times when father or mother smoked, respectively. Cotinine levels in children's urine statistically differentiated children from smoking mothers (Geometric Mean (GM) 19.7 ng/ml; 95% CI 16.83–23.01) and exposed homes (GM 7.1 ng/ml; 95% CI 5.61–8.99) compared with non-exposed homes (GM 4.5 ng/ml; 95% CI 3.71–5.48). Maternal self-reported ETS exposure in homes declined in the four year span between the two time periods from 42.2% to 31.0% (p < 0.01). Nevertheless, most of the children considered non-exposed by their mothers had detectable levels of cotinine above 1 ng/mL in their urine.</p> <p>Conclusion</p> <p>We concluded that cotinine levels determined in cord blood and urine, respectively, were useful for categorizing the children exposed to smoking and showed that a certain increase in ETS exposure during the 4-year follow-up period occurred.</p

Association between levels of Toll-like receptors 2 and 4 and CD14 mRNA and allergy in pregnant women and their offspring.

The microbial environment in early infancy or even in utero may modulate the risk to develop allergic disease. Since Toll-like receptors (TLR) recognize microbial products, we hypothesized that maternal allergies may be associated with decreased levels of TLR2, TLR4 and CD14 mRNA in mothers and their offspring. 185 healthy pregnant women from Germany (n = 48), Hungary (n = 50) and Spain (n = 87) were enrolled in a European multicenter study. Levels of TLR2, TLR4 and CD14 mRNA were quantified in maternal peripheral blood samples taken at delivery and placental cord blood samples. Numbers of TLR2+, TLR4+ and CD14+ monocytes were quantified by flow cytometry in 42 cord blood samples obtained from the German participants. Bivariate and multivariate regression analyses were performed. Maternal allergies were associated with significantly lower levels of TLR2/4/CD14 mRNA in maternal blood and cord blood samples. Maternal and fetal TLR2/4/CD14 mRNA levels were significantly correlated with each other (TLR2 r = 0.42; TLR4 r = 0.58; CD14 r = 0.54). The results suggest that maternal allergy status may affect allergic risk in offspring through a decreased expression of fetal TLR2/4/CD14. &copy; 2005 Elsevier Inc. All rights reserved