Different baseline characteristics are associated with incident wheeze in female and male adolescents.

AIM: To investigate the independent relationships between baseline characteristics and incident wheeze in adolescents, with particular regard to gender. METHODS: Adolescents (N = 959), aged 12-15 years, answered a standardised respiratory questionnaire and underwent height and weight measurements at baseline. Four years later, 96% of the subjects completed a similar questionnaire. The present study included the adolescents without self-reported wheeze at baseline (n = 795; 394 girls). RESULTS: The proportion of adolescents with obesity was higher among subjects with incident wheeze than among subjects who never reported wheeze: 19.1% vs 8.3%. When stratifying for gender, this difference was only found in girls. In stepwise logistic regression models (odds ratios [95% confidence interval]), obesity (2.84 [1.17-6.86]) and rhinitis (3.04 [1.53-6.03]) at baseline and current smoking (2.60 [1.16-5.82]) at follow-up were associated with incident wheeze in girls. For boys, FEV1 <-1.65 standard deviation (3.20 [1.04-9.79]), family asthma (3.16 [1.46-6.86]) and seasonal allergic symptoms (5.61 [2.56-12.27]) at baseline were independently associated with incident wheeze. CONCLUSION: Data stratified by gender showed that obesity in girls and an atopic constitution in boys were independently associated with increased risk of developing wheeze within four years.

Pre- and postnatal exposure to parental smoking and allergic disease through adolescence.

OBJECTIVES: To examine the role of prenatal and postnatal second-hand tobacco smoke (SHS) exposure on asthma, rhinitis, and eczema development up to 16 years of age. METHODS: A birth cohort of 4089 children was followed for 16 years. Information on parental smoking habits, lifestyle factors, and symptoms of allergic disease was gathered using repeated parental questionnaires. Generalized estimating equations assessed the overall and age-specific associations between SHS exposure and allergic disease at ages 1 to 16 years. RESULTS: Exposure to SHS in utero was associated with an overall elevated risk of developing asthma up to 16 years (odds ratio [OR] = 1.45; 95% confidence interval [CI], 1.15-1.83) but not for rhinitis or eczema. After additional adjustment for parental smoking throughout childhood, excess overall risks for asthma remained statistically significant. Moreover, a dose-dependent pattern with SHS was observed. Exposure to SHS during infancy was associated with an overall elevated risk of asthma (OR = 1.23; 95% CI, 1.01-1.51), rhinitis (OR = 1.18; 95% CI, 1.01-1.39), and eczema (OR = 1.26; 95% CI, 1.09-1.45) up to 16 years. When age-specific associations were examined, the elevated risks related to SHS exposure in utero or during infancy were mostly confined to early childhood for asthma and rhinitis, whereas the excess risk of eczema appeared greatest at later ages. CONCLUSIONS: Our findings indicate that early SHS exposure, in utero or during infancy, influences the development of allergic disease up to adolescence. Excess risks for asthma and rhinitis were seen primarily in early childhood, whereas those for eczema occurred at later ages.

Infant wheeze, comorbidities and school age asthma.

BACKGROUND: Factors associated with early onset of wheeze have been described, but there is limited knowledge on which of these infant wheezers who will have developed asthma in school age. The aim was to identify clinical risk factors for asthma in the 8-yr-old children that wheezed during infancy in a population-based setting. METHODS: Three thousand two hundred and fifty-one children from a population-based birth cohort followed prospectively from infancy until age 8 yr were included in the study. Data were analyzed using multivariate logistic regression analysis. RESULTS: Parents reported any wheeze episode before age 2 yr in 823 subjects (25%). Infant wheezers had an almost fourfold risk of asthma at age 8 [adjusted odds ratio (aOR) 3.68, 95% CI 2.74-4.96], equivalent to an asthma prevalence of 14% compared with 4% among non-wheezers (p < 0.001). After adjustments for sex, exposure to tobacco smoke and indoor dampness/mould, allergic heredity (aOR 1.53, 95% CI 1.02-2.30), increased frequency of wheeze (aOR 3.41, 95% CI 2.09-5.56 for children with ≥3 episodes compared with ≤2 episodes during the first 2 yr of life), infant eczema (aOR 2.31, 95% CI 1.52-3.49), and recurrent abdominal pain (aOR 2.33, 95% CI 1.30-4.16) remained risk factors for school age asthma in the infant wheezing group. CONCLUSIONS: Among infant wheezers, allergic heredity, increased severity of wheeze, infant eczema, and recurrent abdominal pain were independent risk factors for asthma at age 8 yr. Among children with three or four of these risk factors, 38% had asthma at school age.

Maternal smoking in pregnancy and asthma in preschool children: a pooled analysis of eight birth cohorts.

RATIONALE: Although epidemiological studies suggest that exposure to maternal smoking during fetal and early life increases the risk of childhood wheezing and asthma, previous studies were not able to differentiate the effects of prenatal from postnatal exposure. OBJECTIVES: To assess the effect of exposure to maternal smoking only during pregnancy on wheeze and asthma among preschool-age children. METHODS: A pooled analysis was performed based on individual participant data from eight European birth cohorts. Cohort-specific effects of maternal smoking during pregnancy, but not during the first year, on wheeze and asthma at 4 to 6 years of age were estimated using logistic regression and then combined using a random effects model. Adjustments were made for sex, parental education, parental asthma, birth weight, and siblings. MEASUREMENTS AND MAIN RESULTS: Among the 21,600 children included in the analysis, 735 children (3.4%) were exposed to maternal smoking exclusively during pregnancy but not in the first year after birth. In the pooled analysis, maternal smoking only during pregnancy was associated with wheeze and asthma at 4 to 6 years of age, with adjusted odds ratios of 1.39 (95% confidence interval, 1.08-1.77) and 1.65 (95% confidence interval, 1.18-2.31), respectively. The likelihood to develop wheeze and asthma increased statistically significantly in a linear dose-dependent manner in relation to maternal daily cigarette consumption during the first trimester of pregnancy. CONCLUSIONS: Maternal smoking during pregnancy appears to increase the risk of wheeze and asthma among children who are not exposed to maternal smoking after birth.

Dyspnea in relation to symptoms of anxiety and depression: A prospective population study.

BACKGROUND: Respiratory symptoms are related to anxiety and depression in several cross-sectional studies but the association has not been explored in longitudinal studies. STUDY OBJECTIVES: To prospectively study the change in dyspnea in relation to symptoms of anxiety and depression over a 9-year time period. METHODS: The study comprised of 515 adults from a population sample who had participated in the European Commission Respiratory Health Survey (ECRHS) I in 1991-1992 and in the ECRHS II in 1999-2000. The questionnaire included a modified British Medical Research Council Scale for dyspnea grading and the Hospital Anxiety and Depression scale questionnaire. RESULTS: The prevalence of dyspnea was 10.7% in the first and 12.6% in the second survey. Symptoms of depression was an independent determinants for dyspnea in both surveys (OR (95% CI) 3.72 (1.51-9.17) and 3.40 (1.49-7.80), respectively). In subjects that did not have dyspnea at the first survey onset of symptoms of anxiety (OR 3.53 (1.03-12.1)) and depression (OR 12.2 (3.97-37.5)) were significantly related to having dyspnea at the second survey, whereas onset of dyspnea was not significantly associated with developing symptoms of anxiety or depression when each disorder was entered separately. CONCLUSION: Our data indicates that there is a causal relationship between development of symptoms of anxiety and depression and dyspnea. Psychological status is therefore an important factor to consider both when evaluating the results of epidemiological respiratory studies and in clinical settings when treating patients that have dyspnea.