Risk Factor For Current Asthma Research Articles

Viral wheezing in early childhood as a risk factor for asthma in young adulthood: A prospective long-term cohort study.

Background and AimsThere is an increased risk of asthma after viral wheezing episodes in early childhood, but unfortunately, prospective longitudinal data until adulthood are mostly lacking. The aim of this cohort study was to evaluate the risk of asthma in young adulthood after hospitalization for viral wheezing episodes in early childhood.MethodsThe original cohort comprised 100 individuals aged <24 months who were hospitalized for viral wheezing episodes in 1992–1993. After the index episode, data on a diagnosis of asthma 1 year later and at median ages of 4.0, 7.2, and 12.3 years were recorded in follow‐up visits. Forty‐nine individuals attended the latest follow‐up visit at the age of 17–20 years. Current asthma was diagnosed based on symptoms at the time of the last follow‐up, use of inhaled corticosteroids and peak expiratory flow monitoring.ResultsA total of 26 (53%) of the 49 cohort individuals had asthma at a mean age of 18.8 years. In multivariate analyses, a diagnosis of asthma 1 year after index hospitalization and at ages 4.0, 7.2, and 12.3 years were significant risk factors for current asthma (adjusted odds ratios [aORs] of 7.13, 8.86, 8.05, and 21.16, respectively). Atopic dermatitis in infancy (aOR: 4.20) and eosinophilia on admission (5.18) were also significant predictive factors for asthma.ConclusionOver half (26/49) of the participants who had been hospitalized for viral wheezing episodes in early childhood had asthma in young adulthood. An asthma diagnosis at any age during childhood, as well as eosinophilia in early childhood, were independent significant predictive factors for asthma.

The Prevalence of Asthma and Asthma-Like Symptoms among Seasonal Agricultural Workers.

Aim The aim of the study was to determine the prevalence and risk factors of asthma and asthma-like symptoms in seasonal agricultural workers living in fields with toxic chemical exposure. Methods European Community Respiratory Health Survey (ECRHS) questionnaire was used to assess the prevalence of asthma and asthma-like symptoms in the study. Results Of the study group, 51.1% (267) were male and the age of the study group ranged from 18 to 88 years and the mean (SD) was 45.68 (13.39) years. The prevalence of asthma attacks in seasonal agricultural workers in the last one year (current prevalence) was 11.2%; the prevalence of asthma (cumulative prevalence) was 15.1%. In the study, smoking was found to be an important risk factor for current asthma. The prevalence of cumulative asthma was higher in seasonal agricultural workers with allergic rhinitis (p < 0.05 for each). Conclusions Seasonal agricultural workers are exposed to the worst conditions of working groups. These difficult conditions also cause many health problems. Asthma has also been identified as an important health problem among seasonal agricultural workers.

Lower respiratory tract infections appear to be the most important risk factor for current asthma in subarctic schoolchildren.

The aim of this study was to identify possible risk factors for current asthma revealed by two studies in Northern Norway in 1985 and 2008 and to evaluate these factors contributing to the increased prevalence of asthma over these 23years. As part of the 'Asthma and allergy study among schoolchildren in Nordland county' we performed a case-control study (70.0% attendance) comparing 153 children with current asthma (cases) to their non-asthmatic controls. The results from this 2008 study were compared to a similar case-control study (93.2% attendance) performed in 1985 based on 62 current asthmatics. In 1985, the most important risk factors for current asthma were repeated lower respiratory tract infections (LRTIs) with adjusted odds ratio (aOR) 52.11, together with urticaria ever and atopic disease in the family. In 2008, the most important risk factors were food allergy with aOR 7.06, LRTIs during the first three years of life with aOR 5.80 and hospitalisation caused by LRTIs. In both studies, LRTI was the most important risk factor for current asthma. Whether or not LRTIs have contributed to the increased asthma prevalence in this population over 23years remains unresolved.

Risk factors for asthma after infant bronchiolitis.

Five studies carried out after bronchiolitis at less than 24months of age, with a follow-up of more than 10years, reported that atopic dermatitis, family asthma, early-life exposure to tobacco smoke and rhinovirus aetiology were early-life risk factors for later asthma. This study evaluated the long-term outcome at 11-13years of age of children who were hospitalized for bronchiolitis in early infancy. We previously prospectively followed 166 children hospitalized for bronchiolitis at less than 6months of age until 5-7years of age. The current study included a structured questionnaire, parental interviews, clinical examinations and bronchodilation test of 138 of those children at 11-13years of age. Respiratory syncytial virus caused 66% of the bronchiolitis cases, and nearly half of the patients were exposed to tobacco smoke in early life. Doctor-diagnosed asthma was present in 13% of the former bronchiolitis patients at 11-13years of age. Maternal asthma was the only independently significant risk factor in early life (adjusted OR 3.45, 95% CI 1.07-11.74), as was allergic rhinitis at 5-7years of age (adjusted OR 4.06, 95% CI 1.35-12.25). After bronchiolitis at less than 6months of age, the risk of doctor-diagnosed asthma at 11-13years was about twice that of the general Finnish population. Maternal asthma was the only independently significant early-life risk factor for current asthma at 11-13years of age.

The Role of Sensitization to Allergen in Asthma Prediction and Prevention.

The burden of asthma in childhood is considerable worldwide, although some populations are much more affected than others. Many attempts have been made by different investigators to identify the factors that could predict asthma development or persistence in childhood. In this review, the relation between atopic sensitization as an indicator of allergy and asthma in childhood will be discussed. Cross sectional studies, carried out in different countries, failed to show any firm correlation between asthma and atopic sensitization. Birth cohort mainly of infants at high risk for asthma and case–control studies showed that atopic sensitization was a risk factor for current asthma in children older than 6 years. In general, clear relations are observed mostly in affluent Western countries, whereas in less affluent countries, the picture is more heterogeneous. For the prediction of asthma development or persistence in school age children, other prerequisites should also be fulfilled such as family history of asthma and wheezing episodes at preschool age. Despite the conductance of different studies regarding the potential role of allergen avoidance for the primary prevention of childhood asthma, it does not seem that this approach is of benefit for primary prevention purposes. However, the identification of children at risk for asthma is of benefit as these subjects could be provided with the best management practices and with the appropriate secondary prevention measures.

Influence of antibiotic use in early childhood on asthma and allergic diseases at age 5

BackgroundIn the past few decades, the prevalence of allergic diseases has increased rapidly worldwide. At the same time, the overuse of antibiotics has been observed, especially in Japan. ObjectiveTo elucidate the association of early childhood antibiotic use with allergic diseases in later childhood at 5 years of age. MethodsRelevant data were extracted from the hospital-based birth cohort study, the Tokyo Children's Health, Illness and Development Study. To identify signs of asthma and allergic diseases in children, the International Study of Asthma and Allergies in Childhood questionnaire was used. Logistic regression models were applied to estimate the effect of antibiotic use on outcomes in later life. ResultsAntibiotic exposure in children within the first 2 years of life was associated with current asthma (adjusted odds ratio [aOR] 1.72, 95% confidence interval [CI] 1.10–2.70), current atopic dermatitis (aOR 1.40, 95% CI 1.01–1.94), and current allergic rhinitis (aOR 1.65, 95% CI 1. 05–2.58) at 5 years of age. Analysis of the associations by type of antibiotics showed that cephem was associated with current asthma (aOR 1.97, 95% CI 1.23–3.16) and current rhinitis (aOR 1.82, 95% CI 1.12–2.93), and macrolide was associated with current atopic dermatitis (aOR 1.58, 95% CI 1.07–2.33). ConclusionOur findings suggest that antibiotic use within the first 2 years of life was a risk factor for current asthma, current atopic dermatitis, and current allergic rhinitis in 5-year-old children.

Different risk factor patterns for adult asthma, rhinitis and eczema: results from West Sweden Asthma Study.

Background Atopic diseases including asthma, rhinitis and eczema have increased in the second half of the past century. This has been well studied among children and adolescents but with the exception of asthma to a much lesser extent in adults. The adult risk factor pattern of atopic diseases, in particular of eczema, and their relation to allergic sensitization are yet to be fully elucidated. Studies among adults that have compared the risk factor pattern for these conditions in the same material are very few. The objective of this study was to compare the risk factor patterns for asthma, rhinitis and eczema in a randomly selected adult population.Methods A questionnaire survey on atopic diseases was dispatched by mail to 30,000 randomly selected individuals in West Sweden aged 16–75 years and 62 % participated. A subgroup of 2000 individuals was selected for clinical examinations including blood sampling for specific serum Immunoglobulin E to common airborne allergens and 1172 attended.ResultsThe prevalence of current asthma was 11.8 %, current rhinitis 42.8 %, current eczema 13.5 and 2.3 % had all three conditions while 13.9 % had at least two conditions. No mutual risk factor was identified for all three conditions. Allergic sensitization was a strong risk factor for current asthma (OR 4.1 CI 2.7–6.3) and current rhinitis (OR 5.1 CI 3.8–6.9) but not so for current eczema. Obesity was a risk factor for current asthma and current rhinitis, while farm childhood decreased the risk for current asthma and current rhinitis. Occupational exposure to gas dust or fumes and female sex was associated with an increased risk of current asthma and current eczema.ConclusionsThere are different risk factor patterns for asthma, rhinitis and eczema in adults but some risk factors are overlapping between some of the conditions. The effect of mutable risk factors should be assessed further in longitudinal studies.Electronic supplementary materialThe online version of this article (doi:10.1186/s13601-016-0112-0) contains supplementary material, which is available to authorized users.

Neighborhood poverty, urban residence, race/ethnicity, and asthma: Rethinking the inner-city asthma epidemic

Although it is thought that inner-city areas have a high burden of asthma, the prevalence of asthma in inner cities across the United States is not known. We sought to estimate the prevalence of current asthma in US children living in inner-city and non-inner-city areas and to examine whether urban residence, poverty, or race/ethnicity are the main drivers of asthma disparities. The National Health Interview Survey 2009-2011 was linked by census tract to data from the US Census and the National Center for Health Statistics. Multivariate logistic regression models adjusted for sex; age; race/ethnicity; residence in an urban, suburban, medium metro, or small metro/rural area; poverty; and birth outside the United States, with current asthma and asthma morbidity as outcome variables. Inner-city areas were defined as urban areas with 20% or more of households at below the poverty line. We included 23,065 children living in 5,853 census tracts. The prevalence of current asthma was 12.9% in inner-city and 10.6% in non-inner-city areas, but this difference was not significant after adjusting for race/ethnicity, region, age, and sex. In fully adjusted models black race, Puerto Rican ethnicity, and lower household income but not residence in poor or urban areas were independent risk factors for current asthma. Household poverty increased the risk of asthma among non-Hispanics and Puerto Ricans but not among other Hispanics. Associations with asthma morbidity were very similar to those with prevalent asthma. Although the prevalence of asthma is high in some inner-city areas, this is largely explained by demographic factors and not by living in an urban neighborhood.

Decreased importance of environmental risk factors for childhood asthma from 1996 to 2006.

The large increase in asthma prevalence continues in several, but not all areas. Despite the individual risk factors that have been identified, the reasons for the observed trends in prevalence are largely unknown. This study sought to characterize what trends in risk factors accompanied trends in asthma prevalence. Two population-based cohorts of 7- to 8-year-old children from the same Swedish study areas examined by expanded International Study of Asthma and Allergy in Childhood questionnaires were compared 10 years apart. In 1996 and 2006, 3430 (97% participation) and 2585 (96% participation) questionnaires were completed, respectively. A subset was skin-prick-tested: in 1996 and 2006, 2148 (88% participation) and 1700 (90% participation) children, respectively. The adjusted population-attributable fraction (aPAF) was calculated using the prevalence and multivariate odds ratio of each risk factor. The prevalence of current asthma and wheeze was similar in 1996 and 2006. Allergic sensitization, however, increased from 21% to 30%. The prevalence of parental asthma increased from 17% to 24%, while respiratory infections and maternal smoking decreased (60% to 29% and 32% to 16%, respectively). The aPAFs of non-environmental risk factors for current asthma increased in 1996-2006: allergic sensitization from 35% to 41%, parental asthma from 27% to 45% and male sex from 20% to 25%. Conversely, the aPAFs of environmental risk factors decreased: respiratory infections from 36% to 32% and damp home and maternal smoking from 14% and 19%, respectively, to near zero in 2006. From 1996 to 2006, the non-environmental risk factors parental asthma, allergic sensitization and male sex had an increasing or constant importance for current asthma in 7- to 8-year-old children. The importance of the environmental exposures damp home, respiratory infections and maternal smoking decreased. This counterbalancing in risk factors may explain the level of prevalence of current asthma.

Rhinitis, asthma and respiratory infections among adults in relation to the home environment in multi-family buildings in Sweden.

Risk factors for rhinitis, asthma and respiratory infections in the home environment were studied by a questionnaire survey. Totally 5775 occupants (≥18 years old) from a stratified random sample of multi-family buildings in Sweden participated (46%). 51.0% had rhinitis in the last 3 months (current rhinitis); 11.5% doctor diagnosed asthma; 46.4% respiratory infections in the last 3 months and 11.9% antibiotic medication for respiratory infections in the last 12 months. Associations between home environment and health were analyzed by multiple logistic regression, controlling for gender, age and smoking and mutual adjustment. Buildings constructed during 1960–1975 were risk factors for day time breathlessness (OR = 1.53, 95%CI 1.03–2.29). And those constructed during 1976–1985 had more current rhinitis (OR = 1.43, 95%CI 1.12–1.84) and respiratory infections (OR = 1.46, 95%CI 1.21–1.78). Cities with higher population density had more current rhinitis (p = 0.008) and respiratory infections (p<0.001). Rented apartments had more current rhinitis (OR = 1.23, 95%CI 1.07–1.40), wheeze (OR = 1.20, 95%CI 1.02–1.41), day time breathlessness (OR = 1.31, 95%CI 1.04–1.66) and respiratory infections (OR = 1.13, 95%CI 1.01–1.26). Living in colder parts of the country was a risk factor for wheeze (p = 0.03) and night time breathlessness (p = 0.002). Building dampness was a risk factor for wheeze (OR = 1.42, 95%CI 1.08–1.86) and day time breathlessness (OR = 1.57, 95%CI 1.09–2.27). Building dampness was a risk factor for health among those below 66 years old. Odor at home was a risk factor for doctor diagnosed asthma (OR = 1.49, 95%CI 1.08–2.06) and current asthma (OR = 1.52, 95%CI 1.03–2.24). Environmental tobacco smoke (ETS) was a risk factor for current asthma (OR = 1.53, 95%CI 1.09–2.16). Window pane condensation was a risk factor for antibiotic medication for respiratory infections (OR = 1.41, 95%CI 1.10–1.82). In conclusion, rhinitis, asthma and respiratory infections were related to a number of factors in the home environment. Certain building years (1961–1985), building dampness, window pane condensation and odor in the dwelling may be risk factors.

Indoor environmental factors associated with wheezing illness and asthma in South Korean children: phase III of the International Study of Asthma and Allergies in Childhood

Background: The relationship between exposure to indoor environmental pollutants and incidence of asthma and wheezing illness in children is unclear. This study aimed to clarify this relationship by identifying the risk factors associated with these conditions in South Korean children aged 6–7 years. Methods: The parents or guardians of 3810 children aged 6–7 years who had participated in the International Study of Asthma and Allergies in Childhood and met the study criteria completed validated questionnaires regarding their children's asthma and wheezing illness, risk factors and exposure to indoor pollutants. The data were subjected to chi-square and multivariate logistic regression analysis to identify the factors significantly associated with asthma and wheezing illness. Results: Parental history of allergic disease (odds ratio [OR]: 1.729; 95% confidence interval [CI]: 1.447–2.066), living on the basement or semi-basement floor (OR: 1.891; 95% CI: 1.194–2.996) and living in housing that had been remodeled within the last 12 months (OR: 1.376; 95% CI: 1.101–1.720) were found to be significantly associated with wheezing illness. Parental history of allergic disease (OR: 2.189; 95% CI: 1.483–3.231), male sex (OR: 1.971; 95% CI: 1.369–2.838) and positive skin prick test (SPT) result (OR: 1.583; 95% CI: 1.804–3.698) were found to be significantly associated with current asthma. Conclusions: Although the risk factors for current asthma appear to be more related to the non-modifiable risk factors like sex, parental history of allergic diseases, SPT, the two groups are associated with exposure to modifiable indoor environmental factors.

Comparison in asthma and allergy prevalence in the two major cities in Greece: the ISAAC phase II survey

Background Variability in the prevalence of allergic diseases has been detected not only between different countries, but also between cities with similar national and different socio-economic or climatic characteristics. The aim of this study was to determine the prevalence of childhood asthma and allergies and which factors are associated with them, in the two largest Greek cities, Athens and Thessaloniki. Methods Two thousand and twenty-three Greek 9-10-year-old schoolchildren from Athens (Central Greece) and Thessaloniki (North Greece, more humid), were included in ISAAC-II study. All participants followed the ISAAC-II protocol by questionnaire, skin prick testing and flexural dermatitis examination. Results Compared with Athens, the prevalence of current wheezing (8.4% vs. 5.7%, p = 0.002), lifetime asthma (11.5% vs. 7.7%, p = 0.004), atopic current asthma (3.2% vs. 1.6%, p = 0.02), allergic rhinitis (8.2% vs. 5.2%, p = 0.007), and hay fever (21.7% vs. 12.5%, p < 0.001) were higher in Thessaloniki. The overall sensitisation rate was also higher in Thessaloniki than in Athens (25.2% vs. 16%, p < 0.001) with more prevalent sensitising due to the perennial allergens ( D. pteronyssinus, D. farinae, Alternaria tenuis) and cat dander. Perennial allergens sensitisation was a risk factor for current asthma in both cities. Conclusion A higher prevalence of asthma symptoms, allergic rhinitis, and sensitisation rate was detected in Greek schoolchildren living in Thessaloniki compared to those in Athens. Allergy to mites and mould was more prevalent in Thessaloniki. The more humid weather of Thessaloniki may be implicated.

Prevalência de sintomas de asma e fatores de risco associados em adolescentes escolares de 13 e 14 anos dos municípios de Tubarão e Capivari de Baixo, Santa Catarina, Brasil

This study aimed to measure the prevalence and severity of asthma symptoms and to investigate the association between asthma symptoms and personal, geographic, and socioeconomic variables in 13-14-year-old schoolchildren enrolled in the 7th and 8th grades in Tubarão and Capivari de Baixo, Santa Catarina State, Brazil. This was a cross-sectional study using the ISAAC (International Study of Asthma and Allergies in Childhood) written questionnaire, applied to 1,870 adolescents enrolled in 42 schools in the two cities, from March to May 2005. Prevalence of current asthma (defined as wheezing in the previous 12 months) was 11.8%, and there was a 7.8% lifetime prevalence of physician-diagnosed asthma. Prevalence of wheezing that interrupted sleep (one or more nights per week) was 2.1%; 8.1% had 1-3 wheezing attacks per year; and 3.7% had wheezing that disturbed their speech. According to multivariate analysis, female gender, family history, parental asthma, rental housing, and smoking inside the home were risk factors for current asthma. Prevalence and severity of current asthma were less than in other Brazilian studies.

No evidence that early use of inhaled corticosteroids reduces current asthma at 10 years of age

It is debated whether early treatment with inhaled corticosteroids (ICS) can change the natural course of childhood asthma. To assess if ICS treatment before 2 years of age in children with obstructive airways disease reduces current asthma at 10 years of age. Children with (n=233) and without (n=219) recurrent (r) bronchial obstruction (BO) attending clinical examination at 2 years of age in the birth cohort Environment and Childhood Asthma study in Oslo, were reinvestigated at 10 years of age. Current asthma (CA) at 10 years was defined as asthma with either symptoms and/or asthma treatment during the last year, and/or 10% fall in forced expired volume in 1s after standardized treadmill run. The risk of CA was assessed by logistic regression and propensity modelling (including gender, parental atopy and severity score at 2 years) in children with rBO who received ICS or not by 2 years. CA was found in 97 children, more often among rBO children with (56.9%) and without ICS treatment (30.8%) compared to no-BO children (5.5%) (p<0.001). In rBO children logistic regression analyses (adjusted odds ratio aOR (95% confidence interval)) identified male gender (aOR 1.82 (1.01-3.27), p=0.046) and severity score at 2 years 1.14 (1.03-1.28), (p=0.01), as significant and ICS treatment as non-significant 2.00 (0.98-4.12) risk factors for CA. With propensity modelling adjusting for disease severity, ICS treatment by 2 years caused a non-significant increased risk aOR of CA of 1.84 (0.89-3.82). No evidence was found that early use of ICS before age two in children with rBO reduces current asthma 8 years later.

Prevalence and correlates of asthma in the elderly

The prevalence of asthma has been increasing for the past two decades. Bronchial asthma in the elderly has not received as much attention as asthma among children and adults. Recent studies have suggested that asthma is not an uncommon condition in the elderly. Our objectives were to determine the prevalence and correlates of asthma and asthma symptoms in the West Texas elderly population. Texas Tech 5000 is a telephone-administered longitudinal health study of the elderly age 65 and older residing in the 108 counties that comprise West Texas. In wave 3 of the survey a total of 3392 subjects participated with a response rate of 89%. Subjects with emphysema were excluded and the analysis was restricted to subjects with non-Hispanic white or Hispanic race or ethnicity ( n = 3021). The sample data were weighted using U.S. Census 2000 West Texas population. The prevalence and predictors of current asthma, probable asthma and wheezing were estimated using survey logistic regression analyses. Health-related quality of life (QoL) was determined using a 15-item mini-Asthma QoL scale and a 12-item SF-12 scale. The prevalence of current asthma was 6.3%, whereas 19.7% reported having wheezing in the previous 12 months. The prevalence of current asthma was lowest among Hispanic Americans (4.1%, 95% CI = 2.0, 6.2). The most common nocturnal asthma symptoms reported were cough and shortness of breath. A significant impairment in QoL (especially for rural residents) was observed for the environmental stimuli domain among subjects with asthma. Significant physical impairment (lower PCS score on the SF-12 scale) was also observed for subjects with current asthma ( P < 0.05). In the multiple logistic regression analysis, Hispanic ethnicity (adjusted odds ratio AOR = 0.46, 95% confidence interval CI = 0.23, 0.91), hay fever (AOR = 3.56, 95% CI = 2.56, 4.95), low income (AOR = 1.84, 95% CI = 1.04, 3.27), history of smoking cigarettes (AOR = 1.48, 95% CI = 1.03, 2.14), two or more ER visits in the previous 12 months (AOR = 2.2, 95% CI = 1.16, 4.17), and severe pain (AOR = 1.55, 95% CI = 1.05, 2.28) were independent risk factors for current asthma. This study identified several risk factors associated with current asthma. Given that older individuals spend most of their time indoors, routine environmental assessment should be considered as part of their asthma management plan.

Sex-race differences in the relationship between obesity and asthma: the behavioral risk factor surveillance system, 2000.

Although prospective data are limited, recent cross-sectional studies support obesity as a cause of asthma. They also suggest that the association is present only among women. Our analysis examines possible sex-race differences in the relationship between obesity and asthma. We examined data from the 2000 Behavioral Risk Factor Surveillance System. To minimize diagnostic bias, the sample was limited to adults aged 18 to 34 years. All cases had doctor-diagnosis of asthma and ongoing symptoms. Multiple logistic regression was used to examine risk factors for current asthma vs. never having asthma. Obesity and asthma were more strongly related among women than men (test for interaction, p<0.01). Across increasing categories of body mass index (BMI), we observed a dose-response relationship among women (odds ratios: 0.9, 1.0 [reference], 1.0, 1.3, 1.5, 1.8, and 3.2) but only a non-significant increased risk in severely obese men (odd ratio: 2.0). In subgroup analyses, however, the obesity-asthma association was present in four of six sex-race/ethnicity subgroups, including black and Hispanic men. Although the obesity-asthma association is stronger among women than men, our analysis demonstrates a strong positive association among men from minority groups. These race-specific results may help explain some of the "inconsistencies" in prior studies.

Maternal asthma, infant feeding, and the risk of asthma in childhood.

Controversy surrounds the issue of whether children with asthmatic mothers should be breast-fed. The aim of this study was to investigate whether maternal asthma status alters the association between asthma and breast-feeding. In a cohort study of 2602 West Australian children enrolled before birth and followed prospectively, we collected data on method of infant feeding, maternal asthma (as reported by parental questionnaire), atopy (as measured by skin prick test), and current asthma (defined as a physician's diagnosis of asthma and wheeze in the last year) at 6 years of age. The risk of childhood asthma increased if exclusive breast-feeding was stopped (other milk was introduced) before 4 months (odds ratio, 1.28; 95% CI, 1.01-1.62; P =.038), and this risk was not altered by atopy or maternal asthma status. After adjusting for covariates, exclusive breast-feeding for less than 4 months was a significant risk factor for current asthma (odds ratio, 1.35; 95% CI, 1.00-1.82; P =.049). There was no formal statistical interaction between breast-feeding and maternal asthma status (P =.970). In this study maternal asthma status did not modify the association between asthma and breast-feeding duration. We recommend that infants with or without a maternal history of asthma be exclusively breast-fed for 4 months and beyond.

Prevalence of asthma and allergic diseases in primary school children in Ankara, Turkey: two cross-sectional studies, five years apart.

The prevalence of allergic diseases is reported to have increased worldwide. Two questionnaire surveys, five years apart, were conducted to evaluate the trend of prevalence rates and possible risk factors among primary school children in Ankara, Turkey. A previous survey in 1992 revealed the lifetime prevalences of asthma, wheezing, allergic rhinitis and atopic dermatitis were 17.4%, 23.3%, 28% and 6.1%, and the prevalences for the last 12 months were 8.3%, 11.9%, 15.4% and 4%, respectively. The survey was repeated with the same questionnaire in the same age group (6-13 years) of the same school in May 1997. The parents of 358 boys and 380 girls completed the questionnaire. The lifetime and last 12 months' prevalences of asthma, wheezing, rhinitis and atopic dermatitis were 16.8%, 22.5%, 18.7%, 6.5%, and 9.8%, 13.3%, 14.1%, 4.3%, respectively. There was a significant change only for the lifetime prevalence of rhinitis (p < 0.001). The rate of indoor smoking had declined from 73.9% to 64%, and pet ownership had risen from 7.9% to 22.9% (p < 0.001 for both). Atopic family history was the most prominent risk factor for all types of allergic disorders. Male gender was a significant risk factor for current asthma and wheezing [odds ratio (OR) = 1.80 and 1.59; 95% confidence intervals (CI) = 1.09-2.98 and 1.01-2.48, respectively], and passive smoking affected the occurrence of allergic rhinitis (OR = 1.84; CI = 1.13-3.00). The prevalence rates of allergic diseases among primary school children in Ankara stabilized during a 5-year period for all diseases other than allergic rhinitis. However, there are changing behavior patterns, i.e. indoor smoking and keeping pet animals, which that may have affected these rates.

Predictors of Asthma Severity in the Elderly: Results of a Community Survey in Northeast England

A number of risk factors for the development and severity of asthma in childhood are known. Particularly, there is information on allergens, excessive use of β2- agonists, and indoor environmental pollutants. Similar information on elderly patients is lacking. We examined the risk factors for current asthma and for the severity of asthma in 95 elderly subjects (>65 years old) compared to 274 elderly subjects with obstructive spirometry who did not have asthma as defined by the following criteria: symptoms of episodic wheeze, cough, or chest tightness and forced expiratory volume in 1 sec/vital capacity (FEV1/VC) <70% with >15% or 200 ml. reversibility in FEV1 to 200 μg salbutamol given from a metered-dose inhaler. The severity of airflow limitation was graded on the basis of the FEV1/VC ratio as mild (60%-70%), moderate (40%-60%), and severe (<40%). Asthma history was collected using the Medical Research Council respiratory questionnaire and a follow-up postal questionnaire. Data were analyzed using multiple logistic regression and the overall goodness-of-fit of the model was checked using the Hosmer-Lemeshow (HL) statistic. History of allergy (to one or more of the following allergens: cat, house dust, or grass or tree pollen) (odds ratio [OR] 25; 95% confidence interval [CI] 13-51; p = 0.0001) and history of childhood wheeze (OR 8; 95% CI 4-9; p = 0.004) were strong predictors of current asthma. Duration of wheezing, smoking history, indoor heating, history of working in coal mines, and sex were not predictors (HL 6.75, degrees of freedom [df] = 8, p = 0.56). Use of >4 puffs of salbutamol/day (OR 5.3; 95% CI 2-14; p = 0.005), more than 10 years of asthma symptoms (OR 4.2; 95% CI 4.1-36.2; p = 0.0001), and >500 mL reversibility in FEV, (OR 4.2; 95% CI 1.2-14.3; p = 0.05) were independent predictors of moderate to severe asthma. History of atopy was the strongest predictor of asthma in the elderly population studied. Indoor heating, presence of pets at home, sex, smoking history, and history of working in coal mines were not predictors of asthma. The severity of asthma as assessed by measurement of airflow limitation was related to the frequency of use of β2-agonists, duration of symptoms of asthma, and increased reversibility of FEV1 to β2-agonist.

Exposure and sensitization to cat dander: Asthma and asthma-like symptoms among adults

Background: Several pets, such as cats, dogs, and rodents, are known to produce allergens. Despite the clinical and laboratory evidence that exposure to pets can cause bronchoconstriction in sensitized subjects, the results of population studies have been contradictory. Objectives: The purpose of this study was to investigate the relationship between cat ownership and the prevalence of asthma, asthma-like symptoms, and bronchitic symptoms among subjects 20 to 44 years of age in Vancouver, Canada and to determine whether sensitization is responsible for such an association. Methods: Two thousand nine hundred ninety-nine (88%) randomly selected subjects responded to a mail questionnaire. Of these, 504 participated in laboratory examination, including allergy skin testing. Results: One thousand nineteen study responders (34%) were pet owners at the time of the study (current owners). Current pet owners were found to have a higher prevalence of current asthma, asthma-like symptoms, and bronchitic symptoms compared with those without pets. Cat owners had significantly higher risk of having current asthma and asthma-like symptoms. In the subset who had allergic skin tests, we found that those who were allergic to cat dander had a significantly higher risk of current asthma than those not allergic to cat dander and not owning a cat. Conclusion: This study provides evidence that sensitization to cat dander is a more important risk factor for current asthma and asthma-like symptoms than cat ownership itself. (J Allergy Clin Immunol 1999;103:60-5.)