Parental smoking and other risk factors for wheezing bronchitis in children

A population-based case-control study was performed to investigate etiologic factors for wheezing bronchitis and asthma in children up to four years of age. A total of 199 children hospitalized for the first time with these diagnoses at a major hospital in Stockholm in 1986–1988 constituted the cases, 351 children from the catchment area of the hospital were used as controls. Information on known and suspected risk factors was obtained through home interviews with a parent. Parental smoking was associated with a relative risk of 1.8 (95% confidence interval 1.3 – 2.6) corresponding to a population attributable proportion of 27%. The strongest association was seen for maternal smoking and children below 18 months of age. Other major risk factors included atopic heredity, recurrent upper respiratory tract infections and breast-feeding less than 3 months, which appeared to interact multiplicatively with parental smoking. The environmental factors had a stronger influence in the youngest age group, and the overall attributable proportion associated with parental smoking, short breast-feeding period and exposure to pets in the household was 43%. It is clear that successful primary prevention could dramatically reduce the incidence of wheezing bronchitis in children.     

Respiratory symptoms at age 8 years in a cohort of very low birth weight children.

The childhood respiratory consequences of very low birth weight (birth weight < or =1,500 g) are incompletely understood, especially since the introduction of recent changes in neonatal care. To assess prevalence, trends, and risk factors for respiratory symptoms, the authors followed to age 8 years a cohort of 384 very low birth weight children from six regional neonatal intensive care units in Wisconsin and Iowa who were born between August 1, 1988, and June 30, 1991. A control group of 154 Wisconsin schoolchildren was also assembled. Respiratory symptoms in the past 12 months and history of asthma ("asthma ever") were reported by parents on a questionnaire used in the International Study of Asthma and Allergies in Childhood (ISAAC). Control group prevalence resembled ISAAC prevalence worldwide and in Canada, but respiratory symptoms were twice as common among very low birth weight children. With advent of the availability of pulmonary surfactants, the prevalence of wheezing at age 8 decreased from 50% to 16% (p = 0.002) among children with bronchopulmonary dysplasia, but it increased from 14% to 38% among those with milder neonatal respiratory disease. Bronchopulmonary dysplasia, family history of asthma, smoking in the household, and patent ductus arteriosus were predictive of wheezing in the previous 12 months. Antenatal steroid therapy had a borderline-significant protective association with wheezing (odds ratio = 0.56, 95% confidence interval: 0.29, 1.1). There were interaction effects between several of the predictors.     

The impact of parental smoking on asthma and wheezing. SIDRIA Collaborative Group. Studi Italiani sui Disturbi Respiratori nell'Infanzia e l'Ambiente.

To evaluate the impact of parental smoking on childhood asthma and wheezing, we studied two random samples of subjects ages 6-7 and 13-14 years in ten areas of northern and central Italy. Standardized questionnaires were completed by parents of 18,737 children and 21,068 adolescents (response rates, 92.8% and 96.3%, respectively) about their smoking habits and the respiratory health of their children. Adolescents were asked about their respiratory health and personal smoking. We compared two groups of cases with healthy subjects: (1) "current asthma" (children, 5.2%; adolescents, 6.2%) and (2) "current wheezing" not labeled as asthma (children = 4.5%, adolescents = 8.5%). Exposure to smoke of at least one parent increased the relative risk of current asthma among children [odds ratio (OR) = 1.34; 95% confidence interval (CI) = 1.11-1.62] and of current wheezing among adolescents (OR = 1.24; 95% CI = 1.07-1.44). Maternal smoking had a stronger effect than paternal smoking. Maternal smoking during pregnancy was associated with current asthma (OR = 1.62; 95% CI = 1.34-1.96) and current wheezing in children (OR = 1.31; 95% CI = 1.06-1.62); the effects were lower among adolescents. Among subjects with a negative history of parental asthma, maternal smoking was associated with current wheezing in both age groups, whereas among those with a positive history of parental asthma it was associated with current asthma in children, but not in adolescents. We estimated that 15% (95% CI = 12-19) of the current asthma cases among children and 11% (95% CI = 8.3-14) of the current wheezing cases among adolescents are attributable to parental smoking in Italy.     

四城市剖宫产与学龄期儿童哮喘发病相关性研究

目的 分析剖宫产与学龄前儿童哮喘的关联,总结剖宫产与儿童哮喘的相关性,指导临床及孕产妇对剖宫产的认识。方法 选取安庆、芜湖、铜陵、扬州4个城市共8 900名3~6岁儿童作为研究对象。通过对儿童带养者问卷调查的形式收集儿童出生方式、哮喘患病情况、人口学资料和体格测量资料等。哮喘病例由县级以上医院确诊,孕妇分娩方式分为阴道分娩、医学指征剖宫产和选择剖宫产。运用多分类Logistic回归分析剖宫产与学龄前儿童哮喘的关联。结果8 900名学龄前儿童中,剖宫产率为67.3%,哮喘患病率为7.0%,哮喘儿童中28.5%出生于自然分娩,71.5%出生于剖宫产。在控制地区、性别、早产、母亲怀孕年龄、父母文化程度、母乳喂养和儿童BMI后,医学指征剖宫产与学龄前儿童哮喘相关联(OR=1.25,95%CI:1.03~1.52,P0.05),而选择性剖宫产与学龄前儿童哮喘的关联无统计学意义(OR=1.19,95%CI:0.94~1.51,P0.05)。结论 剖宫产和学龄前儿童哮喘有关联,并且医学指征剖宫产会增加儿童哮喘发生的风险。     

Day care attendance, recurrent respiratory tract infections and asthma

OBJECTIVE: Our objective was to use a causal model for childhood asthma to determine whether the effect of day care attendance on asthma was mediated by recurrent respiratory tract infections. DESIGN: A cross-sectional survey among 1447 children aged 6-16 years in Oslo. Their parents completed written questionnaires. A recursive logit model was used to estimate direct effects in terms of adjusted odds ratios (aOR). RESULTS: Year of birth, number of siblings and length of maternal education were significantly associated with day care attendance. Attendance at day care increased the risk of early infections, aOR = 1.8 (1.3-2.5), and infections were associated with asthma, aOR = 4.9 (3.4-7.3). The crude association between day care and asthma was cOR = 1.5 (1.0-2.2), whereas the estimated direct effect was small and nonsignificant, aOR = 1.2 (0.8-1.9). The results may be influenced by overreporting of infections among parents of children with asthma. CONCLUSIONS: Our results suggest that children who attend day care have an increased risk of asthma with early infections as a mediator of risk.     

Risk factors for recurrent wheezing in children under 13 years old in the South of Brazil]

OBJECTIVE: To study the prevalence of and major factors associated with recurrent wheezing in children younger than 13 years of age in the urban area of Rio Grande, in the state of Rio Grande do Sul, Brazil. METHODS: The presence of recurrent wheezing was investigated in a cohort as part of a cross-sectional study that was begun in 1997 that focused on the morbidity from respiratory diseases in children then between 0 and 5 years of age. During home visits in 2004 a standardized questionnaire given by trained interviewers was used to obtain information concerning the family's socioeconomic and living conditions, maternal care during pregnancy and delivery, and children's current and previous morbidity patterns. The statistical analysis included the calculation of the odds ratio (OR) and 95% confidence interval (95% CI), with nonconditional logistic regression adjustment for potential confounding factors, according to a predefined hierarchical model. RESULTS: Of the 775 children studied in 1997, 685 were located in 2004 (loss of 11.6%). In this group, the prevalence of recurrent wheezing at the time of the interview was 27.9%. After adjustment, the risk factors were: current rhinitis (OR=45.7; 95% CI: 24.2 to 86.5), use of wood stove for cooking (OR=2.7; 95% CI: 1.4 to 4.9), child's history of acute respiratory infection (OR=2.1; 95% CI: 1.3 to 3.5), bottle feeding (OR=2.1; 95% CI: 1.1 to 3.8), history of asthma in siblings (OR=1.9; 95% CI: 1.2 to 3.2), maternal history of asthma (OR=1.8; 95% CI: 1.1 to 2.9), and fewer than six prenatal medical consultations (OR=1.6; 95% CI: 1.1 to 2.4). Paternal schooling<9 years was a protective factor against recurrent wheezing (OR=0.6; 95% CI: 0.4 to 0.9). CONCLUSIONS: These results suggest that the management of recurrent wheezing and asthma must consider checking for and simultaneously treating rhinitis. The measures to minimize the effects of recurrent wheezing should include educational and treatment programs focusing on asthma.     

Maternal age as a risk factor for wheezing lower respiratory illnesses in the first year of life.

Postneonatal mortality due to respiratory illnesses is known to be inversely related to maternal age, but the possible role of young motherhood as a risk factor for respiratory morbidity in infants has not been thoroughly explored. The authors studied the incidence of lower respiratory tract illnesses during the first year of life, as ascertained by health plan pediatricians, in over 1,200 infants enrolled at birth between 1980 and 1984 in Tucson, Arizona. The incidence of wheezing lower respiratory tract illnesses increased significantly (p = 0.005) with decreasing maternal age, whereas the incidence of nonwheezing lower respiratory tract illness was independent of maternal age. A logistic regression was used to control for the effects of several known confounding factors. When compared with infants of mothers aged more than 30 years, adjusted odds ratios were 2.4 (95% confidence interval 1.8-3.1) for infants whose mothers were less than age 21 years (p < 0.0001), 1.8 (95% confidence interval 1.4-2.3) for infants whose mothers were aged 21-25 (p < 0.0001); and 1.4 (95% confidence interval 1.1-1.6) for infants whose mothers were aged 26-30 (p < 0.001). These results suggest that young motherhood is an important risk factor for wheezing lower respiratory tract illnesses during the first year of life. Both biological and social factors related to maternal age may explain these findings.     

Indoor risk factors for asthma and wheezing among Seattle school children.

Indoor risk factors for physician-diagnosed asthma and wheezing in the past 12 months without previous asthma diagnosis were assessed in a survey of parents of 5-9-year-old Seattle primary school students. Among the 925 respondents, 106 (11%) reported a physician diagnosis of asthma, 66 (7%) had wheezing without diagnosis, and 753 (82%) were asymptomatic. After adjusting for age, sex, gender, ethnicity, medical history, socioeconomic status (SES) and parental asthma status, an increased risk of physician diagnosis of asthma was associated with household water damage, the presence of one or more household tobacco smokers, and at least occasional environmental tobacco smoke (ETS) exposure. Similarly, an increased risk of wheezing in the past 12 months among children without diagnosed asthma was associated with household water damage, presence of one or more household tobacco smokers, and occasional or more frequent ETS exposure. No increased risk of either condition was associated with gas, wood, or kerosene stove use, household mold, basement water, or wall/window dampness. Similarities in the indoor risk factors patterns between diagnosed asthma and wheezing without diagnosis suggested a similar etiology of these two conditions. The slightly higher association between ETS and asthma may indicate that parents of diagnosed asthmatics were more conscious of ETS, and were more likely to prohibit household smoking by resident smokers. Future research is needed to quantify which aspects of household water damage are related to respiratory illness.     

Family size, day-care attendance, and breastfeeding in relation to the incidence of childhood asthma

A hypothesis has been suggested stating that children exposed early to infections are less likely to develop atopy or asthma. The authors investigated the relation between risk of childhood asthma and number of siblings as well as day-care attendance, as factors possibly increasing the likelihood of early infections, and breastfeeding as a factor reducing them. A case-control study was carried out in Montréal, Canada, between 1988 and 1995 that included 457 children diagnosed with asthma at 3--4 years of age and 457 healthy controls. Cases followed for 6 years were later classified as persistent or transient by the symptoms and use of medication after diagnosis. Among cases diagnosed at 3--4 years of age, the adjusted odds ratio for asthma was 0.54 (95% confidence interval (CI): 0.36, 0.80) for one sibling and 0.49 (95% CI: 0.30, 0.81) for two or more. The adjusted odds ratio for day-care attendance before 1 year of age was 0.59 (95% CI: 0.40, 0.87). Results were similar with persistent cases. Among transient cases (who possibly had an infection with wheezing at 3--4 years of age), day-care attendance and a short duration of breastfeeding resulted in increased risk. The results support the hypothesis that opportunity for early infections reduces the risk of asthma.     

Antibiotic exposure by 6 months and asthma and allergy at 6 years: Findings in a cohort of 1,401 US children

Many studies have reported that antibiotic use may be associated with increased risk of childhood asthma. Respiratory tract infections in small children may be difficult to distinguish from early symptoms of asthma, and studies may have been confounded by "protopathic" bias, where antibiotics are used to treat early symptoms of asthma. These analyses of a cohort including 1,401 US children assess the association between antibiotic use within the first 6 months of life and asthma and allergy at 6 years of age between 2003 and 2007. Antibiotic exposure was associated with increased risk of asthma (adjusted odds ratio = 1.52, 95% confidence interval (CI): 1.07, 2.16). The odds ratio if asthma was first diagnosed after 3 years of age was 1.66 (95% CI: 0.99, 2.79) and, in children with no history of lower respiratory infection in the first year of life, the odds ratio was 1.66 (95% CI: 1.12, 3.46). The adverse effect of antibiotics was particularly strong in children with no family history of asthma (odds ratio = 1.89, 95% CI: 1.00, 3.58) (P(interaction) = 0.03). The odds ratio for a positive allergy blood or skin test was 1.59 (95% CI: 1.10, 2.28). The results show that early antibiotic use was associated with asthma and allergy at 6 years of age, and that protopathic bias was unlikely to account for the main findings.     

儿童反复喘息与4位点哮喘基因预测模型的关系及危险因素分析

目的 探讨儿童反复喘息与4位点哮喘基因预测模型的关系,分析反复喘息的危险因素。方法 选取2019年1月—2021年3月在玉环市人民医院住院或门诊就诊的喘息儿童91例,根据哮喘预测指数(API)是否阳性,分为API阳性组55例,API阴性组36例,同时选择健康体检儿童30例为对照组。比较3组儿童4位点哮喘基因预测模型的高危率;将反复喘息儿童进行单因素及多因素Logistic回归分析。结果 API阳性组4位点哮喘基因预测模型的高危率较API阴性组及对照组显著升高(χ²=12.487,P＜0.05);API阳性组4位点哮喘基因预测模型的高危风险是API阴性组的2.54倍,是对照组的5.32倍。单因素分析儿童反复喘息与4位点哮喘基因预测模型的高危型、过敏史、过敏疾病家族史、吸入过敏原阳性、食入过敏原阳性、被动吸烟、嗜酸性粒细胞计数升高及呼吸道合胞病毒感染等因素有关(χ²=13.831,22.817,25.475,20.573,6.373,11.487,10.790,10.789,P＜0.05),而与居住环境无关(P＞0.05)。多因素Logistic回归分析显示4位点哮喘基因预测模型的高危型(OR=5.535,95%CI:1.928~15.893)、过敏史(OR=4.921,95%CI:1.661~14.577)、过敏疾病家族史(OR=4.460,95%CI:1.560~12.749)、吸入过敏原阳性(OR=13.105,95%CI:2.436~70.503)、被动吸烟(OR=3.704,95%CI:1.304~10.521)为喘息的独立危险因素。结论 反复喘息儿童,尤其是API阳性儿童,4位点哮喘基因预测模型的高危率显著升高;反复喘息与多种因素有关,其中4位点哮喘基因预测模型高危型是一个重要原因。     

Plastic wall materials in the home and respiratory health in young children

OBJECTIVES: The relation between the presence of plastic wall materials in the home and respiratory health in children was assessed. METHODS: This population-based cross-sectional study involved 2568 Finnish children aged 1 to 7 years. RESULTS: In logistic regression models, lower respiratory tract symptoms--persistent wheezing (adjusted odds ratio [OR] = 3.42, 95% confidence interval [CI] = 1.13, 10.36), cough (OR = 2.41, 95% CI = 1.04, 5.63), and phlegm (OR = 2.76, 95% CI = 1.03, 7.41)--were strongly related to the presence of plastic wall materials, whereas upper respiratory symptoms were not. The risk of asthma (OR = 1.52, 95% CI = 0.35, 6.71) and pneumonia (OR = 1.81, 95% CI = 0.62, 5.29) was also increased in children exposed to such materials. CONCLUSIONS: Emissions from plastic materials indoors may have adverse effects on the lower respiratory tracts of small children.     

A national study of asthma in childhood.

A history of asthma was obtained in 3.5% of a representative national sample of children aged 11 years. A further 8.8% had a history of wheezy bronchitis. In the 12 months before the interview, 2% had experienced attacks of asthma and a further 2.9% attacks of wheezy bronchitis. Both conditions were significantly more common among boys than girls, and a history of asthma was reported more frequently among children from non-manual than from manual social classes. Children with frequent attacks of wheezing had lower mean relative weights. A history of eczema and hay fever was more frequently discovered in children with reported asthma than in those with wheezy bronchitis, whereas migraine or recurrent headaches, recurrent abdominal pain, and recurrent throat or ear infections were more commonly associated with wheezy bronchitis than with asthma. The modified Rutter home behaviour scale, which reflects the parental view of the child's behaviour, was significantly raised among children with a history of wheezing, but their school behaviour as judged by the Bristol social adjustment guide showed no such difference. In spite of increased absence from school because of illness, no differences were found in educational attainment between children with a history of asthma or wheezy bronchitis and those with neither condition.     

Effects of environmental tobacco smoke on lower respiratory system of children under 5 years of age

OBJECTIVE: To determine the effects of second-hand smoke in the respiratory system of children under 5 years old. METHODS: A cross sectional study of a total of 1,104 children under 5 years old. Information about respiratory symptoms and illness, family history of respiratory diseases, smoking habits of household members and housing conditions were assessed by home interviews with the children's parents. RESULTS: We studied 546 boys and 558 girls. Among 611 children exposed to second-hand smoke, 82% had respiratory problems (odds ratio = 1.64; 95% confidence interval: 1.21-2.20). Children whose parents were smokers at the time of the survey were more likely to experience wheezing than children of nonsmoking parents (odds ratio = 1.66; 95% confidence interval: 1.21-2.27), shortness of breath (odds ratio = 1.91; 95% confidence interval: 1. 36-2.67), morning and day time or night coughs (odds ratio = 1.58; 95% confidence interval: 1.09-2.28). The odds ratio for asthma, bronchitis and pneumonia was greater for children exposed to second-hand smoke (odds ratio = 1.60; 95% confidence interval: 1. 11-2.31). CONCLUSIONS: Maternal smoking, paternal smoking, family history of respiratory diseases, and housing conditions are considered risk factors for respiratory diseases in children.     

Presence of asthma risk factors and environmental exposures related to upper respiratory infection-triggered wheezing in middle school-age children

Viral respiratory infections and exposure to environmental constituents such as tobacco smoke are known or suspected to trigger wheezing/asthma exacerbations in children. However, few population-based data exist that examine the relationship between wheezing triggered by viral respiratory infections and environmental exposures. In this investigation we used population-based data to evaluate differences in exposures between symptomatic middle school-age children who did and did not report wheezing triggered by viral respiratory infections. As part of the North Carolina School Asthma Survey (NCSAS), a 66-question data instrument was used to collect information from children enrolled in North Carolina public middle schools during the 1999-2000 school year. Associations between exposures and upper respiratory infection-triggered wheezing (URI-TW) among symptomatic children were examined using adjusted prevalence odds ratios (PORs). Video methods developed for the International Study of Asthma and Allergies in Childhood were used to assess wheezing. Among the 33,534 NCSAS symptomatic participants, positive associations were observed between most exposures and URI-TW. Reported presence of all allergy variables (PORs ranging from 2.11 to 2.45) was more strongly associated with URI-TW than either smoking or other exposures. Presence of URI-TW was higher at increasing levels of tobacco smoke exposure, but no apparent dose-response effect was observed for other indoor air pollutants. URI-TW in middle school children is most associated with reported allergen sensitivity, relative to other asthma risk factors and environmental exposures. Data from this investigation may be useful in developing assessment, screening, and targeting strategies to improve asthma and wheezing management in children.     

Road traffic and adverse respiratory effects in children. SIDRIA Collaborative Group

OBJECTIVES: To investigate the relation between traffic indicators in the area of residence and the occurrence of chronic respiratory disorders in children. METHODS: A population based survey was conducted in 10 areas of northern and central Italy (autumn 1994 to winter 1995) in two age groups (6-7 and 13-14 years). Information on several respiratory disorders and on traffic near residences was collected with a questionnaire given to children and to their parents. The sample analysed included 39,275 subjects (response rate 94.4%). Outcomes were: (a) early (first 2 years of life) respiratory diseases, and (b) current respiratory disorders (asthma, wheeze, cough, or phlegm in the past year). Odds ratios (ORs) and 95% confidence intervals (95% CIs), adjusted for several potential confounders, were estimated from logistic regression models. Main results were stratified by level of urbanisation (metropolitan areas, other centres). RESULTS: In the metropolitan areas, high frequency of lorry traffic in the street of residence was associated with significantly increased risks for many adverse respiratory outcomes. Among early respiratory diseases, the strongest associations were found for recurrent bronchitis (OR 1.69, 95% CI 1.24 to 2.30), bronchiolitis (1.74, 1.09 to 2.77) and pneumonia (1.84, 1.27 to 2.65), although no association was detected for episodes of wheezing bronchitis. All the current respiratory disorders were positively and consistently associated with frequency of lorry traffic, particularly the most severe bronchitic and wheezing symptoms: persistent phelgm for > 2 months (1.68; 1.14 to 2.48), and severe wheeze limiting speech (1.86; 1.26 to 2.73). No or weaker associations with heavy vehicular traffic were detected in urban and rural areas and no increased risks were found in the whole sample with the reported traffic density in the zone of residence. After extensive evaluations, the potential of reporting bias seems unlikely. CONCLUSION: Exposure to exhausts from heavy vehicular traffic may have several adverse effects on respiratory health of children living in metropolitan areas, increasing the occurrence of lower respiratory tract infections early in life and of wheezing and bronchitic symptoms at school age.

 

     

Prenatal dichlorodiphenyldichloroethylene (DDE) and asthma in children

Prevalence of asthma increases with increasing dichlorodiphenyldichloroethylene (DDE) levels. However, the effect of early-life exposure, the fundamental window of exposure, is unknown. We assessed the association between prenatal DDE and other organochlorine compounds, and atopy and asthma during infancy. All women presenting for antenatal care in Menorca (Spain) over 12 months starting in mid-1997 were invited to take part in a longitudinal study; 482 children were subsequently enrolled, and 468 (97.1%) provided complete outcome data up to the fourth year of study. Prenatal exposure of organochlorine compounds was measured in cord serum in 405 (83%) children. Asthma was defined on the basis of wheezing at 4 years of age, persistent wheezing, or doctor-diagnosed asthma. We measured specific immunoglobulin-E (IgE) against house dust mite, cat, and grass in sera extracted at 4 years of age. DDE (median = 1.03 ng/mL) was detected in all children, as well as hexachlorobenzene (0.68 ng/mL) and polychlorobiphenyls (0.69 ng/mL). Wheezing at 4 years of age increased with DDE concentration, particularly at the highest quartile [9% in the lowest quartile (< 0.57 ng/mL) vs. 19% in the highest quartile (1.90 ng/mL); relative risk = 2.63 (95% confidence interval 1.19-4.69), adjusting for maternal asthma, breast-feeding, education, social class, or other organochlorines]. The association was not modified by IgE sensitization and occurred with the same strength among nonatopic subjects and among those with persistent wheezing or diagnosed asthma. DDE was not associated with atopy alone. Prenatal exposure to DDE residues may contribute to development of asthma.     

Occupational asthma in New Zealanders: a population based study.

OBJECTIVES: To examine the effect of occupation on respiratory symptoms in a randomly selected adult population aged 20-44 years. METHODS: It is based on the phase II sampling of the New Zealand part of the European Community respiratory health survey. 1609 people (63.9% response rate) completed a detailed respiratory questionnaire. Of those responding, 1174 (73%) underwent skin tests and 1126 (70%) attended to undergo methacholine bronchial challenge. Current occupation was recorded and a previous occupation was also recorded if it had led to respiratory problems. 21 occupational groups were used for analysis for the five definitions of asthma wheezing in the previous 12 months; symptoms related to asthma; bronchial hyperresponsiveness (BHR); BHR with wheezing in the previous 12 months; and BHR with symptoms related to asthma. RESULTS: Prevalence odds ratios (ORs) were significantly increased for farmers and farm workers (OR 4.16, 95% confidence interval (95% CI) 1.33 to 13.1 for the combination of wheezing and BHR). Increased risks of prevalence of asthma were also found for laboratory technicians, food processors (other than bakers), chemical workers, and plastic and rubber workers. Workers had also been divided into high and low risk exposure categories according to relevant publications. The prevalence of wheezing was greater in the high risk group (OR 1.57, 95% CI 0.83 to 2.95) than in the low risk group. Atopy was associated with asthma, but the prevalence of atopy did not differ significantly between occupational exposure groups. The attributable risk of wheezing that occurred after the age of 15 years and that was estimated to be due to occupational exposure (based on the defined high risk group) was 1.9%, but this increased to 3.1% when farmers and food processors (other than bakers) were also included in the high risk group. CONCLUSIONS: This population based study has identified certain occupations significantly associated with combinations of asthmatic symptoms and BHR.     

Maternal Prepregnancy Obesity is an Independent Risk Factor for Frequent Wheezing in Infants by Age 14 Months

Background: Maternal prepregnancy obesity has been linked to the offspring's risk for subsequent asthma. We determined whether maternal obesity is associated with increased risk of wheezing phenotypes early in life. Methods: We used data on 1107 mother–child pairs from two birth cohorts from the INMA–INfancia y Medio Ambiente project. Maternal height was measured and prepregnancy weight self‐reported at enrolment (on average at 13.7 ± 2 weeks of gestation). Maternal prepregnancy body mass index was categorised as underweight, normal, overweight and obese according to WHO recommendations. Information on child's wheezing was obtained through questionnaires up to the age of 14 (±1) months. Wheezing was classified as infrequent (<4 reported wheezing episodes) or frequent (≥4 episodes). Weight and length of infants were measured by trained study staff at 14.6 (±1) months of age and weight‐for‐length z‐scores computed. Results: Although maternal obesity did not increase the risk of the child to have any or infrequent wheezing, children of obese mothers were more likely to have frequent wheezing than children of normal‐weight mothers (11.8% vs. 3.8%; P = 0.002). In fully adjusted multinomial logistic regression models, including infants' weight‐for‐length z‐scores and other covariates, maternal prepregnancy obesity was associated with increased risk of frequent [adjusted relative risk (RR) 4.18, 95% confidence interval (CI) 1.55, 11.3] but not infrequent (RR 1.05 [95% CI 0.55, 2.01]) wheezing in their children. Conclusions: Maternal prepregnancy obesity is independently associated with an increased risk of frequent wheezing in the infant by the age of 14 months. These findings add evidence on the potential effects of in utero exposures on asthma‐related phenotypes.     

重症呼吸道合胞病毒肺炎的危险因素分析

目的分析重症呼吸道合胞病毒(RSV)肺炎的流行病学和相关危险因素。方法选取2018年1月1日—2019年12月31日杭州市儿童医院收治的RSV阳性且临床诊断为重症肺炎的患儿80例为重症组,RSV阳性且临床诊断为普通肺炎的患儿80例为普通组,采用Logistic多元回归分析重症RSV肺炎的危险因素。结果重症RSV肺炎单因素相关性分析显示秋冬季发病、小月龄、早产、剖宫产、低出生体质量、缺乏母乳喂养、哮喘家族史及患儿基础疾病因素差异均有统计学意义(均P<0.05)。多因素Logistic回归分析显示:发病季节、月龄、早产、剖宫产、低出生体质量、哮喘家族史及患儿基础疾病与重症RSV肺炎发生率呈现正相关;母乳喂养与重症RSV肺炎发生率呈现负相关,是其保护因素。结论秋冬季为重症RSV肺炎的好发季节,小月龄、早产儿、剖宫产、低出生体质量、哮喘家族史及基础疾病是重症RSV肺炎的危险因素,母乳喂养可降低重症RSV肺炎发生风险。