A persistently high body mass index increases the risk of atopic asthma at school age.

AIM: Being overweight has been associated with the risk of developing childhood asthma, but studies have produced conflicting results, for example with regard to possible links to allergic diseases. This study aimed to explore the relationship between body mass index (BMI) and school-age asthma. METHODS: Data were obtained from a prospective, longitudinal study of 5044 children born in western Sweden. The parents answered questionnaires at six months and one, four-and-a-half and eight years of age. The response rate to the final questionnaire at the age of eight was just over 80%. BMI was adjusted for age and gender, and a high BMI was defined as the 85th percentile and above. RESULTS: A multivariate analysis showed an independently increased risk of doctor-diagnosed asthma among children with a persistently high BMI, both in infancy and at school age, with an adjusted odds ratio (aOR) of 2.9 and a 95% confidence interval (CI) of 1.3-6.4. In addition, persistently high BMI was associated with an increased risk of atopic asthma (aOR 4.7, 95% CI 2.0-11.0). CONCLUSION: A persistently high BMI during childhood increased the risk of doctor-diagnosed asthma at school age. The increased risk of atopic asthma suggests an effect mediated via the immune system.

Antibiotics in the first week of life is a risk factor for allergic rhinitis at school age.

BACKGROUND: Heredity as well as external factors influences the development of allergic rhinitis. The aim of this study was to analyse early risk factors and protective factors for allergic rhinitis at school age. METHODS: This is a prospective, longitudinal study of children born in western Sweden in 2003 where 50% of the birth cohort was randomly selected. The parents answered questionnaires at 6 months, 12 months, 4.5 yr and 8 yr. At 8 yr, 5044 questionnaires were distributed. Of these, 4051 responded, that is, 80.3%. Current allergic rhinitis was defined as symptoms and use of medication during the past 12 months. RESULTS: Current allergic rhinitis at 8 yr was reported by 10.9%. Mean onset age was 5.7 yr, and 61.9% were boys. In a multivariate analysis, antibiotics in the first week of life increased the risk of allergic rhinitis (adjusted odds ratio 1.75, 95% confidence interval (1.03, 2.97)). Increased risk was also seen with parental allergic rhinitis (aOR 2.73 (2.12, 3.52)), food allergy first year (aOR 2.45 (1.61, 3.73)), eczema first year (aOR 1.97 (1.50, 2.59)) and male gender (aOR 1.35 (1.05, 1.74)). Living on a farm at 4.5 yr reduced the risk (aOR 0.31 (0.13, 0.78)). CONCLUSION: Antibiotics in the first week of life increased the risk of allergic rhinitis at school age, while living on a farm at preschool age reduced the risk. Both findings are compatible with the hygiene hypothesis.

Early fish introduction and neonatal antibiotics affect the risk of asthma into school age.

BACKGROUND: The early introduction of fish has been reported to reduce the risk of wheezing disorder in early childhood, while broad-spectrum antibiotics in the first week have been associated with an increased risk. However, it is uncertain whether the effects remain into school age. The aim was to explore these risk factors for doctor-diagnosed asthma at 8 years. METHODS: Data were obtained from a prospective, longitudinal study of a cohort of children born in western Sweden. The parents answered questionnaires at 6 months and 1, 4.5 and 8 years of age. The response rate at 8 years was 80% of the questionnaires distributed (4051/5044), that is, 71% of the families entering the study (4051/5654). RESULTS: At 8 years, 5.7% reported current doctor-diagnosed asthma. Of these, 65% had atopic asthma and 35% non-atopic asthma. In the multivariate analysis, atopic heredity, male gender and own allergic disease during infancy were risk factors for doctor-diagnosed asthma at 8 years. In addition, the introduction of fish before the age of 9 months independently reduced the risk (adjusted OR 0.6; 95% CI 0.4-0.96), while broad-spectrum antibiotics in the first week independently increased the risk of current asthma at school age (aOR 2.3; 1.2-4.2). Regarding types of asthma, the effects were significant in atopic asthma but not in non-atopic asthma. CONCLUSION: The early introduction of fish and neonatal antibiotic treatment influence the risk of asthma into school age. The significant effect on atopic asthma is of particular importance, as this phenotype is of major clinical significance.

Early protective and risk factors for allergic rhinitis at age 4½ yr.

Allergic heredity plays a major role in the development of allergic rhinitis. In addition the introduction of food may influence the risk of subsequent allergic disease. The aim of this study was to analyse early risk factors and protective factors for allergic rhinitis at preschool age. Data were obtained from a prospective, longitudinal study of a cohort of children born in the region of western Sweden in 2003 and 8,176 families (50% of the birth cohort) were randomly selected. The parents answered questionnaires at 6 and 12 months and at 4½ yr of age. The response rate at 4½ yr was 4,496, i.e. 83% of the 5,398 questionnaires distributed at 4½ yr. At 4½ yr of age, 5.5% reported symptoms of allergic rhinitis during the last year. In the multivariate analysis, independent risk factors for allergic rhinitis were: allergic sensitisation to food allergens at 4½ yr (OR 10.21; 95% confidence interval 4.22-24.73), recurrent wheeze at 4½ yr (3.33; 1.56-7.10), doctor-diagnosed eczema at 4½ yr (2.72; 1.62-4.55), parental rhinitis (2.21; 1.39-3.53), eczema first year (1.97; 1.19-3.26) and male gender (1.82; 1.13-2.94). The risk was reduced with fish introduction before 9 months (0.49; 0.29-0.82). In conclusion, we found that previous and present allergic disease, heredity and male gender increased the risk of allergic rhinitis at 4½ yr of age. The introduction of fish before the age of 9 months reduced the risk.

Neonatal antibiotic treatment is a risk factor for early wheezing.

OBJECTIVE: The use of antibiotics in infancy and subsequent changes in the intestinal bacterial flora have been discussed as risk factors for the development of asthma. However, it has been difficult to exclude the possibility that antibiotics have been given in early episodes of wheezing. As a result, there has been a risk of reverse causation. To minimize the risk of reverse causation, we have focused on the effect of antibiotics that are already administered on the neonatal ward. METHODS: In a cohort study of infants born in western Sweden in 2003, we studied the development of wheezing. The families of the infants were randomly selected and sent a questionnaire at child ages 6 and 12 months. The response rate was 68.5% to the 6-month questionnaire and 68.9% to the 12-month questionnaire. RESULTS: At 12 months, 20.2% of infants had had 1 or more episodes of wheezing, and 5.3% had had 3 or more episodes. Inhaled corticosteroids had been taken by 4.1% of the infants. Independent risk factors for wheezing disorder treated with inhaled corticosteroids were neonatal antibiotic treatment, male gender, gestational age of <37 weeks, having a mother with asthma, having a sibling with asthma or eczema, and breastfeeding for <5 months. CONCLUSIONS: Treatment with antibiotics in the neonatal period was an independent risk factor for wheezing that was treated with inhaled corticosteroids at 12 months of age. These results indirectly support the hypothesis that an alteration in the intestinal flora can increase the risk of subsequent wheezing.

[Bronchial obstruction and eczema unexpectedly common among Swedish infants. Interesting findings in an questionnaire study about food and life style habits of small children]. / Luftrörsobstruktiva besvär och eksem oväntat vanligt hos svenska spädbarn. Intressanta fynd i enkätstudie om kost- och levnadsvanor hos småbarn.

In our questionnaire study of 599 six-month-old and 512 twelve-month-old infants born in Western Sweden, we found that parents continued to adhere to outdated primary preventive recommendations against introducing eggs and fish early in the diet. Thirty-five percent of parents had not introduced eggs and 15% of the parents had not introduced fish by the time the infant was ten months old. We could also confirm a high prevalence of wheezing. At twelve months, 17.6% had had one or more episode of wheezing. Of the twelve-month-old infants, 4.1% had received or were being given inhaled corticosteroids. Twenty-five% had or had had eczema at twelve months. 11% had been admitted to a neonatal ward and one-half of these had then been given broad-spectrum antibiotics (5.9% of all twelve-month-old infants in the study). 37% of the households kept fur-bearing pets. We believe that the questionnaire used in this study can be a useful instrument for estimating the effects of lifestyle and environmental factors on the development of future asthma and allergy.

[Parents have accepted the advice on how to prevent sudden infant death]. / Föräldrar har tagit till sig råden för att förebygga plötslig spädbarnsdöd.

We have compared 430 healthy Swedish infants born between 1991 and 1995 with 599 healthy, six months old infants born in 2002, regarding the prevalence of risk factors for SIDS. Following the introduction of the campaign to reduce the risk of SIDS in Sweden in 1992, we could see a decrease in prone sleeping from 32% to 7% together with an increase in supine sleeping from 35% to 44%. Maternal smoking during pregnancy has gone down from 24% to 10%. The prevalence of breast feeding, already high in Sweden in the 90s, was largely unchanged, 69% at six months of age in 2002. This comparison shows that parents of small infants have accepted the advice on ways to reduce the risk of SIDS, and that information given at infant welfare clinics is still effective ten years later. Further improvements are possible by changing the side sleeping position to supine, and by decreasing tobacco smoking among pregnant mothers.