Risk factors for wheeze in the last 12 months in preschool children. (49/1139)

Most children with asthma develop their symptoms before the age of 5 years and many preschool wheezers continue to wheeze in the early school years. It is thus important to investigate the factors that predispose young children to wheeze. The objective of this study was to investigate the relevant environmental and family influences on recent wheeze (wheeze within the last 12 months) in preschool children. A cross-sectional study was conducted in five primary health clinics in the district of Kota Bharu from April to October 1998. Nurses from these clinics distributed Bahasa Malaysia questionnaires containing questions on asthma symptoms, environmental risk factors, family's social status and family history of atopy and wheeze to preschool children aged 1-5 years during their home visits. The respondents were parent(s) or carer(s) of the children. A total of 2,524 (87.7%) complete questionnaires were available for analysis of risk factors. One hundred and fifty six (6.2%) children had current wheeze. Significant risk factors associated with current wheeze were a family history of asthma (O.R. = 6.36, 95% C.I. = 4.45-9.09), neonatal hospital admission (O.R. = 2.38, 95% C.I. = 1.51 - 3.75), and a maternal (O.R. = 2.12, 95% C.I. = 1.31-3.41) or paternal (O.R. = 1.52, 95% C.I. = 0.95-2.43) history of allergic rhinitis. Among environmental factors examined, namely, household pets, carpeting in bedroom, use of fumigation mats, mosquito coils and aerosol insect repellents, maternal and paternal smoking, and air conditioning, none were associated with an increased risk of wheeze. In conclusion, the strongest association with current wheeze was a family history of asthma. Also significant were neonatal hospital admission and a history of allergic rhinitis in either the mother or father. None of the environmental factors studied were related to current wheeze in preschool children.  (+info)

Prevalence of wheeze during childhood: retrospective and prospective assessment. (50/1139)

The question "Has your child ever had wheezing or whistling in the chest at any time in the past?" is a simple and widely used proxy measure for the lifetime prevalence of asthma. Our aim was to test its validity in a longitudinal survey, comparing retrospective recall with prospective assessment of lifetime prevalence. A population-based cohort of 1,422 children, surveyed twice previously, was studied again at age 8-13 yrs by postal questionnaire using standardized questions from the International Study of Asthma and Allergies in Childhood (ISAAC). Of those traced (1,190) questionnaires were returned by 89%. The prevalence of current wheeze was higher than in the previous surveys (20.5% versus 12.4% and 12.5%). Reported "wheeze ever" increased significantly from survey 1 (15.6%) to survey 2 (22.4%) and survey 3 (39.2%) and was very similar to the cumulative lifetime prevalence assessed prospectively over three surveys (42.8%). The retrospective question had a good negative predictive value (97%) and a reasonable positive predictive value (65%) compared to prospective assessment. Children reporting "wheeze ever" (but not current wheeze) in surveys 1 and 2 had at survey 3 an asthma prevalence higher than never-wheezers but lower than current-wheezers. It is concluded that retrospective recall of wheeze at age 8-13 yrs is a valid proxy measure for the lifetime prevalence of wheeze.  (+info)

Diet and childhood asthma in a society in transition: a study in urban and rural Saudi Arabia. (51/1139)

BACKGROUND: The causes of the worldwide increases in asthma and allergic diseases in childhood, which seem to relate to increasing prosperity, are unknown. We have previously hypothesised that a reduction in the antioxidant component of the diet is an important factor. An investigation was undertaken of dietary and other risk factors for asthma in Saudi Arabia where major lifestyle differences and prevalences of allergic disease are found in different communities. METHODS: From a cross sectional study of 1444 children with a mean age of 12 (SD 1) years in Jeddah and a group of rural Saudi villages, we selected 114 cases with a history of asthma and wheeze in the last 12 months and 202 controls who had never complained of wheeze or asthma, as recorded on the ISAAC questionnaire. Risk factors for asthma and allergies (family history, social class, infections, immunisations, family size, and diet) were ascertained by questionnaire. Atopy was assessed by skin prick testing. RESULTS: In univariate analyses, family history, atopy, and eating at fast food outlets were significant risk factors for wheezy illness, as were the lowest intakes of milk and vegetables and of fibre, vitamin E, calcium, magnesium, sodium, and potassium. These differences were present also in the urban children considered separately. Sex, family size, social class, infections, and parental smoking showed no relationship to risk. In multiple logistic regression analysis, urban residence, positive skin tests, family history of allergic disease, and the lowest intakes of vitamin E, magnesium and sodium related significantly and independently to risk. The lowest tertile of intake of vitamin E was associated with a threefold (95% CI 1.38 to 6.50) increase in risk when adjusted for the other factors. Intake of milk and vegetables both showed inverse linear relationships to being a case. CONCLUSIONS: This study suggests that dietary factors during childhood are an important influence in determining the expression of wheezy illness, after allowing for urban/rural residence, sex, family history, and atopy. The findings are consistent with previous studies in adults and with the hypothesis that change in diet has been a determinant of the worldwide increases in asthma and allergies.  (+info)

Siblings, day-care attendance, and the risk of asthma and wheezing during childhood. (52/1139)

BACKGROUND: Young children with older siblings and those who attend day care are at increased risk for infections, which in turn may protect against the development of allergic diseases, including asthma. However, the results of studies examining the relation between exposure to other children and the subsequent development of asthma have been conflicting. METHODS: In a study involving 1035 children followed since birth as part of the Tucson Children's Respiratory Study, we determined the incidence of asthma (defined as at least one episode of asthma diagnosed by a physician when the child was 6 to 13 years old) and the prevalence of frequent wheezing (more than three wheezing episodes during the preceding year) in relation to the number of siblings at home and in relation to attendance at day care during infancy. RESULTS: The presence of one or more older siblings at home protected against the development of asthma (adjusted relative risk for each additional older sibling, 0.8; 95 percent confidence interval, 0.7 to 1.0; P=0.04), as did attendance at day care during the first six months of life (adjusted relative risk, 0.4; 95 percent confidence interval, 0.2 to 1.0; P=0.04). Children with more exposure to other children at home or at day care were more likely to have frequent wheezing at the age of 2 years than children with little or no exposure (adjusted relative risk, 1.4; 95 percent confidence interval, 1.1 to 1.8; P=0.01) but were less likely to have frequent wheezing from the age of 6 (adjusted relative risk, 0.8; 95 percent confidence interval, 0.6 to 1.0; P=0.03) through the age of 13 (adjusted relative risk, 0.3; 95 percent confidence interval, 0.2 to 0.5; P<0.001). CONCLUSIONS: Exposure of young children to older children at home or to other children at day care protects against the development of asthma and frequent wheezing later in childhood.  (+info)

Wheeze associated with prenatal tobacco smoke exposure: a prospective, longitudinal study. ALSPAC Study Team. (53/1139)

AIMS: To determine whether maternal smoking during pregnancy is a risk factor for reported wheeze in early childhood that is independent of postnatal environmental tobacco smoke (ETS) exposure and other known risk factors. METHODS: A total of 8561 mothers and infants completed questions about smoking during pregnancy, ETS exposure, and the mother's recall of wheeze during early childhood. RESULTS: A total of 1869 (21.8%) children had reported wheeze between 18 and 30 months of age, and 3496 (40.8%) had reported wheeze in one or more of the three study periods (birth to 6 months, 6-18 months, 18-30 months). The risk of wheeze between 18 and 30 months of age was higher if the mother smoked during pregnancy. This relation did not show a dose-response effect and became less obvious after adjustment for the effects of other factors. Average daily duration of ETS exposure reported at 6 months of age showed a dose-response effect and conferred a similar risk of reported wheeze. Factors associated with early childhood wheeze had the following adjusted odds ratios: maternal history of asthma 2.03 (1.74 to 2. 37); preterm delivery 1.66 (1.30 to 2.13); male sex 1.42 (1.28 to 1. 59); rented accommodation 1.29 (1.11 to 1.51); and each additional child in household 1.13 (1.04 to 1.24). CONCLUSIONS: Maternal smoking during pregnancy may be a risk factor for reported wheeze during early childhood that is independent of postnatal ETS exposure. For wheeze between 18 and 30 months of age, light smoking during the third trimester of pregnancy appears to confer the same risk as heavier smoking.  (+info)

Chemokine concentrations in nasal washings of infants with rhinovirus illnesses. (54/1139)

We determined RANTES (regulated on activation, normal T cell expressed and secreted) and interleukin-8 (IL-8) concentrations, and total white blood cell (WBC) and differential counts in nasal wash samples from rhinovirus-infected infants presenting with wheezing or acute upper respiratory illness alone and compared them with those from healthy infants. RANTES concentrations were significantly greater in acute samples from wheezy patients than in those from patients with acute upper respiratory illness only, or in control samples. IL-8 concentrations and WBC and neutrophil counts were significantly greater in acute samples from wheezy infants and patients with upper respiratory illness alone than in control samples, but they did not differ significantly between the 2 patient groups.  (+info)

Comparison of asthma prevalence in the ISAAC and the ECRHS. ISAAC Steering Committee and the European Community Respiratory Health Survey. International Study of Asthma and Allergies in Childhood. (55/1139)

International and regional prevalence comparisons are required to test and generate hypotheses regarding the causes of increasing asthma prevalence in various age groups worldwide. The International Study of Asthma and Allergies in Childhood (ISAAC) is the first such study in children and the European Community Respiratory Health Survey (ECRHS) is the first such study in adults. Therefore, a comparison of the findings of these two surveys was conducted, for the 17 countries in which both surveys were undertaken. There was a strong correlation between the ISAAC and ECRHS prevalence data, with 64% of the variation at the country level, and 74% of the variation at the centre level, in the prevalence of "wheeze in the last 12 months" in the ECRHS phase I data being explained by the variation in the ISAAC phase I data. There was also generally good agreement in the international patterns observed in the two surveys for self-reported asthma (74% of country level and 36% of centre level variation explained), self-reported asthma before age 14 yrs (64 and 26%), hay fever (61 and 73%) and eczema (41 and 50%). Thus although there were differences in the absolute levels of prevalence observed in the two surveys, there is good overall agreement between the International Study of Asthma and Allergies in Childhood and European Community Respiratory Health Survey study findings with regard to international prevalence patterns. These findings, therefore, add support to the validity of the two studies, which provide a new picture of global patterns of asthma prevalence from child- to adulthood, and identify some of the key phenomena which future research must address.  (+info)

When a "wheeze" is not a wheeze: acoustic analysis of breath sounds in infants. (56/1139)

Epidemiological studies indicate that the prevalence of "wheeze" is very high in early childhood. However, it is clear that parents and clinicians frequently use the term "wheeze" for a range of audible respiratory noises. The commonest audible sounds originating from the lower airways in infancy are ruttles, which differ from classical wheeze in that the sound is much lower in pitch, with a continuous rattling quality and lacking any musical features. The aim of this study was to clearly differentiate wheeze and ruttles objectively using acoustic analysis. Lung sounds were recorded in 15 infants, seven with wheeze and eight with ruttles, using a small sensitive piezoelectric accelerometer, and information relating to the respiratory cycle was obtained using inductive plethysmography. The acoustic signals were analysed using a fast fourier transformation technique (Respiratory Acoustics Laboratory Environment programme). The acoustic properties of the two noises were shown to be quite distinct, the classical wheeze being characterized by a sinusoidal waveform with one or more distinct peaks in the power spectrum display; the ruttle is represented by an irregular nonsinusoidal waveform with diffuse peaks in the power spectrum and with increased sound intensity at a frequency of <600 Hz. It is important for clinicians and epidemiologists to recognize that there are distinct types of audible respiratory noise in early life with characteristic acoustic properties.  (+info)