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Abstract: Background: Some human and animal studies have recently shown that maternal grandmother's smoking during pregnancy increases the risk of asthma in the grandchildren. We have investigated whether sex of the exposed parent and/or grandchild modifies the association between grandmaternal smoking and grandchild asthma. Methods: We formed a cohort study based on linkage of national registries with prospectively collected data over three generations. Smoking habits in early pregnancy were registered since 1982 and purchases of prescribed medication since 2005. In all, 10 329 children born since 2005 had information on maternal and grandmaternal smoking on both sides and were followed from birth up to 6 years of age. Ages when medication was purchased were used to classify the cohort into never, early transient (0‐3 years), early persistent (0‐3 and 4‐6 years), and late‐onset (4‐6 years) phenotypes of childhood asthma. Results: Maternal grandmother's smoking was associated with an increased odds of early persistent asthma after adjustment for maternal smoking and other confounders (odds ratio 1.29, 95% confidence interval 1.10‐1.51). Grandchild sex did not modify the association. Paternal grandmother's smoking was not associated with any of the asthma phenotypes. Conclusion: Maternal but not paternal exposure to nicotine before conception was related to an increased risk of early persistent childhood asthma, but not other asthma phenotypes. Our findings are possibly consistent with a sex‐specific mode of epigenetic transfer. [ABSTRACT FROM AUTHOR]

Aim: We evaluated whether body mass index (BMI) and rapid growth in early life were associated with an increased risk of becoming overweight at 16 and 18 years of age.Methods: The study population comprised all children born in Sweden on the 15th of each month in 1981. Individuals born on the 5th, 10th and 20th of every month were added for counties with low population densities. Information on weight and height was collected from birth up to 18 years of age for 98.6% of the 3537 children identified.Results: Weight at 12 months of age was associated with being overweight at both 16 and 18 years of age. Rapid weight gain from birth to 12 months was associated with higher odds for being overweight later in life, and the weight gain between 18 months and four years of age was the strongest risk factor for being overweight in late adolescence in both sexes. There was no association between a birthweight of <2500 g or >4500 g and being overweight at 16 or 18 years of age.Conclusion: Fast growth during early childhood was associated with an increased risk of being overweight later in life, emphasising the importance of early prevention. [ABSTRACT FROM AUTHOR]

Low levels of secretory IgA (SIgA) and transient IgA deficiency have been associated with an increased risk for allergy, but data are conflicting. The aim was to assess the relationship between salivary SIgA antibody levels at 1 yr and wheezing at age four in a birth cohort, in particular the possible protective role of salivary SIgA in sensitized children. Saliva samples were obtained from all children (n = 67) with a positive skin prick test (SPT) at 1 yr and 212 children with a negative SPT. In all, 200 of these children responded to questionnaires at 4 yrs and 183 were skin prick tested at that age. The levels of salivary SIgA and salivary IgA antibodies to the most common food allergen egg and inhalant allergen cat were analyzed by ELISA. Serum was analyzed for IgE antibodies to egg and cat. Development of late-onset wheezing was associated with low SIgA levels in children with positive SPT to at least one allergen both at 1 and 4 yrs of age (p = 0.04), as well as in children with circulating IgE antibodies to egg or cat at 1 yr (p = 0.02). None of nine persistently sensitized children with SIgA levels in the upper quartile developed wheezing, when compared to 10/20 children with lower levels (p = 0.01). Older siblings, more than three infections during infancy, at least one smoking parent, and male gender, were all associated with SIgA in the upper quartile. In conclusion, high levels of SIgA antibodies in sensitized infants were associated with significantly less late-onset wheezing, supporting a protective role against development of asthmatic symptoms. Recurrent infections and other factors supporting an increased microbial pressure during infancy were associated with high levels of salivary SIgA. [ABSTRACT FROM AUTHOR]

Aim: To investigate whether functional changes of the gut flora over time were related to sensitization and allergic symptoms at four years of age. Methods: The levels of short chain fatty acids (SCFAs) in faecal samples at one (n = 139) and four (n = 53) years of age were related to the development of positive skin prick tests (SPT) and allergic symptoms during the first four years of life. Results: Faecal acetic (p < 0.01) and propionic (p < 0.01) acids decreased from one to four years of age, while valeric acid (p < 0.001) increased. Low levels of i-butyric (p = 0.01), i-valeric (p = 0.03) and valeric acids (p = 0.02) at one year were associated with questionnaire-reported symptoms of food allergy at four years. Positive SPTs and allergic symptoms at four years were associated with low faecal levels of i-butyric, i-valeric and valeric acids. At one year of age, infants with, as compared to without older siblings had higher median levels of valeric acid. Conclusion: A slow functional maturation of the gut microflora, as measured by faecal levels of SCFAs is associated with allergy both at one and four years. The findings lend further support to an association between allergy and the development of microbial diversity. [ABSTRACT FROM AUTHOR]

Aim: To assess the temporal trend for asthma and asthma-like symptoms over a period of 20 years. Method: Repeated cross-sectional surveys with identical study design were carried out among all school children (7–16 years) in a well-defined area in Sweden in 1985, 1995 and 2005. Results: In 2005, the parents of 1110 out of 7825 children (14.2%) answered yes to a screening question on asthmatic symptoms. Of these, 783 out of 1110 (70.5%) replied to a postal questionnaire with detailed questions concerning symptoms and asthma management. The rate of affirmative response to the screening question was unchanged between 1995 and 2005. However, the percentage of children with wheezing or three or more asthma-like symptoms decreased, whereas the percentage of children with physician-diagnosed asthma increased steadily since 1985. The number of reported symptoms was closely associated with the number of days with physical restriction. The annual sale of inhaled steroids from local pharmacies was stable between 1995 and 2005. Conclusion: The increase in asthmatic symptoms in school children has peaked. Reduced severity of symptoms and divergent trends for wheezing and physician-diagnosed asthma suggest an increased awareness of asthma with improved management of the symptoms. However, differences in trends between allergic and nonallergic asthma could not be excluded. [ABSTRACT FROM AUTHOR]

Sandin A, Björkstén B, Bråbäck L. Development of atopy and wheezing symptoms in relation to heredity and early pet keeping in a Swedish birth cohort. Pediatr Allergy Immunol 2004: 15: 316–322. © 2004 Blackwell Munksgaard The role of pet keeping during infancy for the development of allergy and asthma is still controversial. The objective of this population-based birth cohort study was to assess the development of atopy and different wheezing phenotypes during the first 4 yr of life in relation to heredity and early pet keeping. The cohort comprised all 1228 infants living in a Swedish county who were born over a 1-yr period. The parents replied to repeated questionnaires and 817 of the children were skin prick tested both at 1 and 4 yr. Cat keeping during the first year of life was associated with an increased risk of a positive skin prick test to cat at 1 yr of age [odds ratio (OR) 2.2, 95% confidence interval (CI) 0.9–5.6], but neither with sensitivity nor clinical symptoms of allergy at 4 yr. Dog keeping during the first year of life was associated with an increased risk of early-onset transient wheezing, but only in children with parental asthma (adjusted OR 4.3, 95% CI 1.5–12.1). In contrast, early dog keeping had an inverse association with sensitivity to pollen allergen at 4 yr (adjusted OR 0.3, 95% CI 0.1–0.9) and late-onset wheezing (adjusted OR 0.4, 95% CI 0.2–1.0). Thus, pet keeping during the first year of life was not associated with an increased risk of atopy at 4 yr, although a positive SPT to cat was more common at 1 yr. Our findings may even suggest that dog keeping during the first year of life might provide some protection from pollen allergy and late-onset wheezing and increase the risk of early-onset transient wheezing in children with heredity for asthma. [ABSTRACT FROM AUTHOR]