Jessica Magnusson

Genome-wide association study of body mass index in 23 000 individuals with and without asthma

Both asthma and obesity are complex disorders that are influenced by environmental and genetic factors. Shared genetic factors between asthma and obesity have been proposed to partly explain epidemiological findings of co‐morbidity between these conditions.

Dietary Intake, FTO genetic variants, and adiposity: A combined analysis of over 16,000 children and adolescents

The FTO gene harbors variation with the strongest effect on adiposity and obesity risk. Previous data support a role for FTO variation in influencing food intake. We conducted a combined analysis of 16,094 boys and girls aged 1–18 years from 14 studies to examine the following: 1) the association between the FTO rs9939609 variant (or a proxy) and total energy and macronutrient intake; and 2) the interaction between the FTO variant and dietary intake, and the effect on BMI. We found that the BMI-increasing allele (minor allele) of the FTO variant was associated with increased total energy intake (effect per allele = 14.3 kcal/day [95% CI 5.9, 22.7 kcal/day], P = 6.5 × 10−4), but not with protein, carbohydrate, or fat intake. We also found that protein intake modified the association between the FTO variant and BMI (interactive effect per allele = 0.08 SD [0.03, 0.12 SD], P for interaction = 7.2 × 10−4): the association between FTO genotype and BMI was much stronger in individuals with high protein intake (effect per allele = 0.10 SD [0.07, 0.13 SD], P = 8.2 × 10−10) than in those with low intake (effect per allele = 0.04 SD [0.01, 0.07 SD], P = 0.02). Our results suggest that the FTO variant that confers a predisposition to higher BMI is associated with higher total energy intake, and that lower dietary protein intake attenuates the association between FTO genotype and adiposity in children and adolescents.

Fish consumption in infancy and development of allergic disease up to age 12 y

BACKGROUND Fish intake in infancy has been associated with reduced risk of allergic disease in early childhood, but it is unknown whether this effect remains as children grow older. OBJECTIVE We studied the possible effect of fish consumption in infancy on prevalent and incident allergic disease up to the age of 12 y. DESIGN A total of 3285 children from a prospective Swedish birth cohort (Children, Asthma, Milieu, Stockholm, Epidemiology) were included in the current analyses. At 1, 2, 4, 8, and 12 y, parental questionnaires were used to obtain information on lifestyle factors, environmental exposures, and symptoms of allergic disease. The frequency of fish intake in infancy was assessed in the 1-y questionnaire. Serum immunoglobulin (Ig) E concentrations associated with common allergens were obtained at age 8 y. Generalized estimating equations and multivariate logistic regression were used to examine associations between fish consumption in infancy and prevalent and incident allergic disease at ages 1-12 y, including sensitization and IgE-associated disease at age 8 y. RESULTS At 1 y of age, 80% of the children consumed fish regularly (ie, ≥2 times/mo). From 1 to 12 y of age, regular fish consumption in infancy reduced overall risks of prevalent and incident allergic disease [adjusted OR (95% CI) after restriction to children without early symptoms of allergic disease was 0.74 (0.60, 0.90) (P = 0.003) for prevalent rhinitis and 0.78 (0.63, 0.97) (P = 0.028) for prevalent eczema. CONCLUSION Regular fish consumption in infancy may reduce risk of allergic disease up to age 12 y.

Maternal body mass index in early pregnancy and offspring asthma, rhinitis and eczema up to 16 years of age

Maternal obesity has been linked to offspring asthma; however, other allergy‐related diseases, as well as the association beyond early school age, are largely unstudied.

Antioxidant intake and allergic disease in children

Antioxidant intake may reduce the risk of allergic disease by protecting against oxidative tissue damage. Major sources of antioxidants in the Western world are fruits, vegetables (vitamin C, β‐carotene, α‐tocopherol), meat and milk (selenium, magnesium, zinc). Children may exclude or eat less of some fruits and vegetables due to cross‐reactivity between pollen and these foods, complicating assessment of causal relationships.

Early Childhood Overweight and Asthma and Allergic Sensitization at 8 Years of Age

Objectives: Our aim was to examine the associations between high BMI and changes in BMI status during the first 7 years of life and asthma and allergic sensitization at age 8 years. Methods: A birth cohort of newborn infants was followed for 8 years. Repeated parental questionnaires provided information on environmental exposures and health outcomes. Information on height and weight during childhood was retrieved from preschool and school health care records. The analyses included the 2075 children for whom information was available on weight and height, as well as on asthma, at age 8 years. Results: A high BMI (≥85th percentile) at age 1, 4, and/or 7 years was associated with an increased risk of asthma at age 8 years. However, no significant association was observed among children with high BMI at age 12 and/or 18 months (early age) or at age 4 years who developed a normal BMI by age 7 years. The risk was increased among children with high BMI at age 7 years, regardless of their earlier weight. Moreover, we observed an increased risk of sensitization to inhalant allergens among children with high BMI at age 7 years. Conclusions: Our study indicates that high BMI during the first 4 years does not increase the risk of asthma at school age among children who have developed a normal weight by age 7 years. However, high BMI at age 7 years is associated with an increased risk of asthma and sensitization to inhalant allergens.

Fish and polyunsaturated fat intake and development of allergic and nonallergic rhinitis

BACKGROUND Rhinitis is one of the most common diseases in childhood. Fish, polyunsaturated fatty acid (PUFA), and vitamin D intakes have been hypothesized to affect the risk of allergic disease; however, it is unclear whether these are linked to the development of rhinitis. OBJECTIVE We sought to assess potential associations between consumption of fish, dietary n-3 and n-6 PUFAs, and vitamin D at age 8 years and development of allergic rhinitis (AR) and nonallergic rhinitis (NAR) between the ages of 8 and 16 years. METHODS We included 1970 participants from a birth cohort. Data on dietary intake was obtained from a food frequency questionnaire at age 8 years. The rhinitis definition was based on questionnaires and IgE measures. RESULTS The prevalence of rhinitis symptoms at age 8 years was 19% (n = 380). Among the 1590 children without rhinitis symptoms at age 8 years, 21% (n = 337) had AR between ages 8 and 16 years, and 15% (n = 236) had NAR. Regular intake of oily fish and higher long-chain n-3 PUFA intake were associated with a reduced risk of cumulative incidence of NAR (adjusted odds ratio, 0.52 [95% CI, 0.32-0.87] for oily fish; odds ratio, 0.45 [95% CI, 0.30-0.67] for highest vs lowest tertile of long-chain n-3 PUFAs; P trend < .001). The results for rhinitis, irrespective of AR and NAR, were in line with the findings for NAR. CONCLUSION Regular consumption of oily fish and dietary long-chain n-3 PUFAs in childhood might decrease the risk of rhinitis, especially NAR, between the ages of 8 and 16 years.

Age at adiposity rebound and body mass index trajectory from early childhood to adolescence; differences by breastfeeding and maternal immigration background

This paper aims to assess association between breastfeeding and maternal immigration background and body mass index development trajectories from age 2 to 16 years.

Body Mass Index Development and Asthma Throughout Childhood

Abstract Several studies have found an association between overweight and asthma, yet the temporal relationship between their onsets remains unclear. We investigated the development of body mass index (BMI) from birth to adolescence among 2,818 children with and without asthma from a Swedish birth cohort study, the BAMSE (a Swedish acronym for “children, allergy, milieu, Stockholm, epidemiology”) Project, during 1994–2013. Measured weight and height were available at 13 time points throughout childhood. Asthma phenotypes (transient, persistent, and late-onset) were defined by timing of onset and remission. Quantile regression was used to analyze percentiles of BMI, and generalized estimating equations were used to analyze the association between asthma phenotypes and the risk of high BMI. Among females, BMI development differed between children with and without asthma, with the highest BMI being seen among females with persistent asthma. The difference existed throughout childhood but increased with age. For example, females with persistent asthma had 2.33 times’ (95% confidence interval: 1.21, 4.49) greater odds of having a BMI above the 85th percentile at age ≥15 years than females without asthma. Among males, no clear associations between asthma and BMI were observed. In this study, persistent asthma was associated with high BMI throughout childhood among females, whereas no consistent association was observed among males.

Body mass index development from birth to early adolescence; effect of perinatal characteristics and maternal migration background in a Swedish cohort.

Background Well documented diversity in risk of developing overweight and obesity between children of immigrant and of native mothers, might be explained by different body mass index (BMI) development trajectories in relation to maternal and perinatal characteristics of offspring. Objectives To assess BMI development trajectories among children born to immigrant and to Swedish mothers from birth to adolescence in relation to perinatal characteristics. Methods A cohort of 2517 children born in Stockholm during 1994 to 1996 was followed with repeated measurement of height and weight at eleven time points until age 12 years. We estimated changes over time for BMI in relation to maternal and perinatal characteristics of offspring using mixed linear model analysis for repeated measure data. Results We observed a significant BMI change over time in children and time interaction with maternal migration status (P<0.0001). Estimated BMI over time adjusted for maternal and perinatal characteristics of offspring, showed slower BMI growth before age of 5, followed by an earlier plateau and steeper BMI growth after 5 years among children of immigrant mothers compared with children of Swedish mothers. These differences in BMI growth were more prominent among children with mothers from outside Europe. Conclusion Beside reinforcing early childhood as a crucial period in development of overweight, the observed slower BMI development at early childhood among children of immigrants followed by a steeper increase in BMI compared with children of Swedish mothers is important for further studies and for planning of preventive public health programs.