The "healthy passive smoker": relationship between bronchial hyper-reactivity in school children and maternal smoking.
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Asthma↗
Biomedical subjects
T Frischer
Publications and source records attributed to T Frischer.
[Adverse health effects in children caused by passive smoking].
The harmful effects of passive smoking (PSE) start early in intrauterine life and comprise direct toxic effects of components of tobaccos smoke on the fetus as well as indirect effects by impeding the normal nutrition of the growing child over effects on the placenta. Consequences are diminished birthweight, and increased perinatal mortality. The sudden infant death syndrome is associated with PSE as are increased incidence of respiratory illnesses in early childhood. Increased bronchial responsiveness, increased asthma prevalence, delayed lung growth and increased incidence of chronic respiratory symptoms later in childhood may well put these children at increased risk for developing chronic obstructive pulmonary disease in their later life.
Adolescent↗
The effects of ambient NO2 on lung function in primary schoolchildren.
The effect of ambient NO2 on lung function was investigated in a sample of 423 schoolchildren. At each of four locations NO2 was monitored continuously. Over a 6-month period from January to June 1990 two surveys were performed and spirometry recorded each time for each child. Linear regression was used to estimate the effect of NO2 for different time intervals preceding lung function testing. A decrease of NO2 between surveys was significantly associated with a higher forced vital capacity (FVC) at the second survey. For each microgram/m3 NO2 decrease the model predicted an increase in FVC of 1.5 ml [for the 2-hr mean (P < 0.05)] and 3.1 ml [for the 12-hr mean (P < 0.01)]. We conclude that even at NO2 levels below current air-quality standards children demonstrate significant changes in lung function.
Air Pollutants↗
Risk factors for childhood asthma and recurrent wheezy bronchitis.
Using cross-sectional data of an epidemiological study, risk factors for asthma and recurrent wheezy bronchitis were investigated in 1812 primary school children. Children with asthma (n = 63) had a similar pattern but a higher frequency of chronic respiratory symptoms than those with recurrent wheezy bronchitis (n = 136). Logistic regression analyses showed similar risk factors for both disorders, however, more pronounced for asthma. Prematurity was a significant risk factor for asthma and for recurrent wheezy bronchitis. Children with asthma more often had a family history of paternal or maternal asthma and their mothers tended to be younger. Effects of paternal asthma and prematurity were also found when the atopic status of the child (defined as skin test positivity to any of seven aero allergens) was taken into account. Next to genetic effects, adverse circumstances in early life seem to be important for the development of asthma. In school children recurrent wheezy bronchitis and asthma seem to be similar disorders which differ in quantitative but not qualitative aspects.
Asthma↗
Sensitization to four common inhalant allergens within 302 nuclear families.
The coincidence of allergic sensitization was investigated in 302 school-aged children and their parents. Specific sensitization to four common inhalant allergens (grass and birch pollens, cat dander, Dermatophagoides pteronyssinus) was ascertained by means of skin-prick tests (SPT) carried out on the complete family unit at the beginning of a 22-month follow-up period. The same test procedure was then repeated on the children twice at 11-month intervals to provide cumulative prevalences of sensitization. A clinical history of atopy in the children (hay fever or asthma; n = 47), which was derived from an interview, is associated with sensitization (positive SPT in 89%). For three allergens (grass and birch pollens, cat dander) sensitization occurs significantly more frequently in the children of mothers who are sensitized to the same allergen (odds-ratios (ORs), 2.5-4.1). Additionally, in three of the four explanatory models related to a single antigen, maternal sensitization to one of the complementary allergens is of importance (ORs, 2.7-3.7). In contrast to this finding, none of the paternal sensitizations has statistical significance. Based on a reaction to at least one of the four allergens, the child's relative risk to be sensitized is increased in case of maternal (OR, 2.88; P = 0.001) but not of paternal (OR, 1.06; P = 0.83) sensitization. In conclusion, our data indicate that the maternal status is more predictive than that of the father with regard to the child's risk of sensitization.
Administration, Inhalation↗
Relation between response to exercise and diurnal variability of peak expiratory flow in primary school children.
BACKGROUND: Variability in peak expiratory flow (PEF) has been proposed as a simple method of screening for asthma in epidemiological studies. This study was designed to assess whether the bronchial response to exercise and the diurnal variation in PEF identified the same subjects. METHODS: Bronchial response to a free running exercise test was assessed in a cohort of 918 seven year old children and was compared with variability of PEF as assessed by twice daily recordings for a one week period. Mini Wright peak flow meters were used throughout the study. RESULTS: Baseline PEFs of both tests were highly correlated but there was no significant correlation between a response to exercise and variability of PEF. Of 33 children with a physician's diagnosis of asthma, 18 had at least one abnormal test, but only five children were abnormal in both tests, showing that the tests did not identify the same subjects. CONCLUSION: Increased variability of PEF, as well as a response to exercise, was associated with respiratory symptoms, but only a response to exercise was closely associated with atopy (defined as a positive skin test to any of seven aero-allergens).
Asthma↗
Seasonal and allergenic predictors of bronchial responsiveness to distilled water.
To evaluate a possible seasonal change in bronchial responsiveness and the relation of such change to atopy, we administered 2,537 bronchial challenge tests in winter and spring to a dynamic population cohort of children 7 to 10 yr of age. The bronchial challenge test consisted of 10 min of tidal inhalation of an aerosol of ultrasonically nebulized distilled water; the resulting percentage decrease in FEV1 (dFEV1%) was recorded. Atopy was determined on the basis of skin-test positivity (any wheal with a diameter greater than that obtained with a positive control) to seven allergens (cat dander, dog dander, house-dust mite, birch, raygrass, orchard grass, and Alternaria). Greater bronchial responsiveness in winter was independently and significantly predicted by a physician's diagnosis of asthma (difference in dFEV1%, 5.6; 95% confidence intervals [95% CI], 2.8 to 8.5; p = 0.0001) and by shortness of breath (difference in dFEV1%, 4.2; 95% CI, 2.1 to 6.3; p = 0.0001). These factors were also predictive of greater responsiveness in the spring, as was atopy (difference in dFEV1%, 3.2; 95% CI, 1.8 to 4.6; p = 0.0001). Analysis of specific allergens further revealed that reactivity to perennial allergens (house-dust mite, cat dander) was predictive of bronchial responsiveness in both winter and spring. However, the change in responsiveness between seasons was most significantly predicted by allergy to seasonal grass pollen, i.e., ragweed or orchard grass (change in dFEV1%, 2.6; 95% CI, 0.6 to 4.5; p = 0.01). In summary, our study demonstrates increased bronchial responsiveness in spring among children allergic to grass pollen.(ABSTRACT TRUNCATED AT 250 WORDS)
Aerosols↗
Influence of maternal smoking on variability of peak expiratory flow rate in school children.
Diurnal variability of peak expiratory flow rates (PEFRs) was assessed in 1,237 children. The PEFR was measured twice daily over a 1-week period. As an index of variability, the log of a week's mean of daily amplitude was calculated. Linear regression analyses revealed a significant positive association between maternal smoking and the variability of PEFR for nonasthmatic children. For these children, exposure to maternal smoking was associated with a 13.7 percent increase (confidence interval [CI], 3.8 to 24.7 percent) in PEFR variability. For asthmatic children an effect was found for nonatopic (54.7 percent increase; CI, 5.5 to 226.8 percent) but not for atopic children (-8.5 percent change; CI, -41.2 to 42.3 percent). In the latter group, there was evidence that mothers changed their smoking habits subsequent to the development of disease in their children. We conclude that exposure to maternal smoking can increase the variability of PEFR and thus might contribute to the development of asthma.
Adult↗
[Variability of peak expiratory flow in an unselected sample of school children].
In the framework of an epidemiological study, the information by peak flow variability (PEFV) was compared to the history of asthma in a non-selected population of primary-school children (n = 1812). PEFV as assessed by twice daily recordings of PEF for a one week period (n = 1237) was calculated as average of daily amplitudes (AVAM: average amplitude mean) in the case of at least complete data for five days (n = 991). Elevated PEFV defined as AVAM > 12%, was cross-tabulated with the asthma history (self-administered questionnaire). The median (90%-confidence-interval) of AVAM is 6.3% (2.2-15.9%). In 11.2% (n = 111) of the population, AVAM > 12% occurred). The sensitivity of AVAM > 12% with regard to "doctor's diagnosed asthma" (n = 35) is 37%. Under exclusion of children with recurrent wheezy bronchitis a specificity for AVAM > 12% of 90% is found. Our data on primary-school children suggests that PEFV is a specific but only slightly sensitive measurement with regard to previously diagnosed bronchial asthma.
Adult↗
[Asthma screening with a standardized running test].
Exercise induced asthma is a common feature of asthma in childhood. We performed a standardized free running test in 1461 primary schoolchildren in first grade (mean age: 7.3 years). A decrease of peak expiratory flow of at least 15% after a 6 minutes exercise period was considered a positive response. For a lifetime prevalence of a physician's diagnosis of asthma the sensitivity of the test was 35.4% and the specificity 94.3%. A positive response was associated with atopy (defined as a positive skin prick test) and with the clinical severity of asthma.
Asthma↗
[Bronchial hyperreactivity to distilled water].
For an epidemiological study 446 children were challenged with distilled water. The protocol consisted of 10 minutes tidal inhalation of an ultrasonically nebulized aerosol of distilled water. For children presenting with a clinical diagnosis of asthma the odds ratio for a positive challenge test was 9.1 compared to non-asthmatics [95% confidence intervals: 2.4-34.9; p = 0.001]. Symptoms cough (p = 0.03), cough at night (p = 0.03) and atopy defined by prick-test (p = 0.001) were also significantly associated with a positive challenge. The easy conduct of our protocol, the--from a pathophysiological point of view--"close to asthma" stimulus, and the small number of side-effects, indicate that the challenge with distilled water can be regarded as an alternative to metacholine provocation testing.
Aerosols↗
Maternal smoking in early childhood: a risk factor for bronchial responsiveness to exercise in primary-school children.
The relationship between maternal smoking and bronchial hyperresponsiveness as assessed by a standardized free running test was investigated in a cohort of 1812 primary-school children in first grade. A child's exposure to maternal smoking during pregnancy, the first year of life, and the study year was recorded. Current exposure was not positively associated with bronchial hyperresponsiveness. The prevalence of this disorder was higher when maternal smoking during the child's first year of life was reported (9%) than when it was not (5.9%). The odds of being hyperresponsive were significantly higher in children exposed to maternal smoking in their first year of life (odds ratio, 2.82; 95% confidence interval, 1.25 to 6.34; p less than 0.01), especially in children with asthma (odds ratio, 20.55; 95% confidence interval, 2.5 to 168.9; p less than 0.01). Current exposure to maternal smoking was associated with less hyperresponsiveness. The effect of current maternal smoking might reflect changes in smoking habits by mothers of children with symptoms, whereas exposure to tobacco smoke in early life might be causally related to bronchial hyperresponsiveness. Our findings support the general hypothesis that early lung injuries have an impact on the later respiratory health of children.
Asthma, Exercise-Induced↗
Early childhood risk factors for sensitization at school age.
Early childhood risk factors for current sensitization were investigated by use of cross-sectional data of a longitudinal study in Southwest Germany. Information was gathered by questionnaires from 1812 families of whom 1470 children 6 to 8 years old were tested by means of a skin prick test (SPT) with seven aeroallergens. Groups with sensitization (n = 201; positive SPT to grass pollens 6.6%, Dermatophagoides pteronyssinus 6.5%, Dermatophagoides farinae 4.4%, cat dander 4.6%, any of the tested allergens 13.7%) are compared with children without sensitization (n = 1269). As risk factors for any sensitization parental atopy (odds ratio [OR]/95% confidence interval [95%CI]: unilateral 1.9/1.3 to 2.6; bilateral 2.8/1.5 to 5.2), low gestational age (1.9/1.1 to 3.2), and male gender (1.6/1.2 to 2.3) are statistically significant in multiple logistic regression. Former cat ownership is significantly related to sensitization to cat dander (2.7/1.4 to 5.5). Breast feeding, maternal smoking habits after the child's birth, prior exposure to pets, and social class are not important. In conclusion, our data suggest parental atopy, low gestational age, and male gender as independent risk factors for sensitization to aeroallergens at school age.
Air Pollutants↗
Longitudinal variability of skin prick test results.
The skin prick test (SPT) is a commonly used procedure for assessing a specific sensitization. The longitudinal variability of test results is of interest for clinical as well as epidemiological investigations. The sensitization to four common aeroallergens (grass pollen, birch pollen, Dermatophagoides pteronyssinus, cat dander) is investigated within the framework of three consecutive SPTs at 11-month intervals for a population of 587 schoolchildren. The prevalence of sensitization based on a weal diameter of at least 2 mm was between 12.9% (cat dander) and 23.9% (grass pollen) in the initial testing. The positive predictive values of the initial SPT were between 75.3% (birch pollen) and 88.2% (cat dander) for the two subsequent SPTs. In the case of initially negative tests with positive second and third SPTs the incidence ranged between 3.2% (cat dander) and 4.3% (birch pollen) per year. A clear increase in the intensity of reaction in subsequent tests was observed in a number of probands testing positively in the initial SPT. In conclusion, our data indicate a high long-term stability of a specific sensitization to aeroallergens in SPT.
Adolescent↗
Clinical atopy and associated factors in primary-school pupils.
To investigate potential risk factors for clinical atopy in childhood, we obtained cross-sectional data from a cohort of 1376 8-year-old pupils. Parental atopy (hay fever, asthma, eczema), gestational age, maternal smoking habits, and the child's history of asthma, hay fever, and eczema were ascertained by questionnaire. Combining the history and the result of a skin prick test using seven aeroallergens, we defined the child's atopic diseases. Of the population evaluated, 25.4% were categorized as atopic (10.2% allergic asthma, 17.3% eczema, 6.9% hay fever). As compared with the clear nonatopics (40.2%), parental atopic diseases were more prevalent in each of the atopic groups. Significant associations of the parents' and child's disease were obvious for eczema and hay fever. Low gestational age (LGA) was more frequent in children with any atopy or with an allergic asthma (odds ratio (OR) 1.7; 95% confidence interval (CI) 1.02-2.97; OR 2.8; 95% CI 1.5-5.4). Hay fever and allergic asthma occurred less frequently in girls (OR 0.5; 95% confidence interval 0.3-0.8; OR 0.6; 95% CI 0.4-0.9). In conclusion, our data underline the importance of parental atopy for the clinical outcome in the offspring. In addition, LGA appears to be a risk factor for allergic asthma and for general atopy in later life.
Austria↗
Relationship between low birth weight and respiratory symptoms in a cohort of primary school children.
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Asthma↗
Determinants of airway response to challenge with distilled water in a population sample of children aged 7 to 10 years old.
We challenged 446 schoolchildren and measured the percent decrease in FEV1 following 10 min of tidal inhalation of UNDW. Assessment tools for respiratory symptoms and atopy were questionnaire and skin testing, respectively. A previous diagnosis of asthma was most strongly associated with a positive airway response (defined as a fall in FEV1 greater than or equal to 10 percent. A positive response was also associated with atopy, presence of cough, cough during night, or any respiratory symptom. A child's age and the prechallenge FEF75% also explained response to distilled water indicating less responsiveness for older children and those with relative greater airway diameter. For the previous diagnosis of asthma, a positive distilled water challenge test had a sensitivity of 36 percent and a specificity of 92 percent. We conclude that a significant relationship between airway response to distilled water, asthma and symptoms suggestive for asthma exists for a childhood population sample.
Asthma↗
[Effects of traffic-induced emissions on the pediatric respiratory tract].
The aim of this study was to investigate the relationship between paediatric pulmonary function and air pollution. For this purpose, 511 primary schoolchildren (mean age 9 years) from areas with different emission data in Austria were submitted to pulmonary function testing every 2 months in the period 1987/1988. Emission data were provided for NO2, SO2, and O3 by permanent measuring stations for the whole of the period under observation. Statistical analysis using the Mantel-Henzel procedure revealed an independent significantly significant effect of NO2 concentration 2 to 6 hours before the function test on the prevalence of obstructive function.
Air Pollutants↗