Attendance to day care centers increases the risk of upper respiratory symptoms and infections in 3- to 5-year-old children. The starting age seems to be an important determinant of recurrent otitis media as well as asthma. The effect of day care center attendance on asthma is limited to age up to 2 years. This effect is most likely mediated via early respiratory tract infections that are substantially more common in children in day care centers compared with children in home care.

B Br re ea as st tf fe ee ed di in ng g, , m ma at te er rn na al l s sm mo ok ki in ng g a an nd d P. Nafstad*, J.J.K. Jaakkola* + , J.A. Hagen*, G. Botten*, J. Kongerud** Breastfeeding, maternal smoking and lower respiratory tract infections. P. Nafstad, J.J.K. Jaakkola, J.A. Hagen, G. Botten, J. Kongerud. ERS Journals Ltd 1996. ABSTRACT: The objective of the study was to assess the relationship between breastfeeding and lower respiratory tract infections (LRTIs) during the first year of life, with special reference to maternal smoking.A cohort of 3,754 children born in 1992-1993 in the City of Oslo, Norway was recruited and data were collected at birth, 6 and 12 months of age. Complete information was obtained from 3,238 children (follow-up rate 86%). The main outcome was an episode of a LRTI, such as pneumonia, bronchitis or bronchiolitis, based on a self-administered questionnaire addressed to parents when the child was 6 and 12 months old. The outcome was specified as physician-diagnosed.In logistic regression analysis adjusting for confounding, maternal smoking increased the risk of LRTIs in children breastfed for 0-6 months (odds ratio (AOR) 1.7; 95% confidence interval (95% CI) 1.2-2.4), but not essentially when the child was breastfed for more than 6 months (AOR 1.1; 95% CI 0.7-1.6). Short-term breastfeeding (0-6 months) and no maternal smoking was related to an adjusted AOR of LRTIs of 1.3 (95% CI 1.0-1.7), and short-term breastfeeding combined with maternal smoking was related to an adjusted AOR of 2.2 (95% CI 1.6-3.1), as compared with long-term breastfeeding and no maternal smoking.The present study indicates a protective effect of long-term breastfeeding on the risk of lower respiratory tract infection during the first year of life. The results suggest that the protective effect is strongest in children exposed to environmental tobacco smoke.

Nicotine measurement in hair is a practical and valid method for estimating average ETS exposure in children. An underreporting of ETS exposure was indicated.

No abstract

In order to assess the relationship between recurrent acute otitis media (rAOM) and age at first acute otitis media (AOM) episode, a prospective cohort of 3754 Norwegian children born in 1992-1993 was followed from birth to 2 years. Recurrent acute otitis media was defined by the criterion of four or more episodes of AOM during a 12-month period. Approximately 5.4% of the children experienced rAOM before the age of 2. Furthermore, children whose first AOM episode occurred before the age of 9 months were at a significantly higher risk for developing rAOM compared to children whose first AOM episode was 10-12 months. In children who had the first ear infection during the first 9 months of life, one-quarter developed rAOM before the age of 2. Multiple logistic regression analysis adjusted for confounding showed that gender and a familial history of atopy were significantly associated with rAOM. In conclusion, the present study found an association between age at first AOM episode and the later subsequent AOM proneness. Additionally, both gender and a family history of atopy seemed to predispose towards otitis-proneness.

No abstract

The concentration of particulate matter in outdoor air, as indicated by daily measures of particulate matter 10 microm in diameter (PM10) in many cities, has been found to be associated with the daily number of deaths and hospital admissions in these cities. To understand this association better, we studied the daily number of hospital admissions for respiratory diseases and the concentrations of eight pollutants in ambient air, during a period of 38 months, in an area with cold winters and air pollution that comes mainly from motor vehicles. We estimated the changes in risk of hospitalization by interquartile increases in pollutant concentrations by Poisson regression analyses. Controlling for periodic trends and weather, the relative risk of hospitalization associated with an interquartile increase of PM10 was 1.038 [95% confidence interval (CI) = 0.991-1.087]. In contrast, the relative risk associated with benzene was 1.105 (95% CI = 1.047-1.166). In a two-pollutant model, the relative risk estimates were 1.014 (95% CI = 0.966-1.063) for PM10 and 1.090 (95% CI = 1.031-1.153) for benzene. We evaluated other two- and three-pollutant models and concluded that pollutants other than PM10 are more strongly associated with hospital admissions for respiratory diseases.

Objective-To assess the weight gain during the first year of life in relation to maternal smoking during pregnancy and the duration of breastfeeding. Design-This was a one year cohort study.