Overweight in relation to allergic disease in childhood and adolescence

The prevalences of childhood overweight and allergic diseases have increased in parallel during the last decades. The overall aim of this thesis was to investigate the associations between overweight (maternal and childhood) and allergic diseases, as well as lung function, throughout childhood up to adolescence. In addition, we investigated the validity of self-reported height, weight and corresponding body mass index (BMI) among Swedish adolescents. All studies were based on the BAMSE study, a population-based birth cohort of 4,089 children followed until age 16 years. Maternal BMI was obtained from the Swedish medical birth register, while childhood BMI was measured at clinical investigations, collected from child and school health care records and self-reported. Allergic diseases were assessed by repeated questionnaires regarding symptoms and medications, while allergic sensitization to inhalant allergens was defined by the presence of specific immunoglobulin E (IgE)-antibodies in blood. Lung function was measured by spirometry at 8 and 16 years and by impulse oscillometry (IOS) at 16 years. The results of Study I showed that maternal BMI in early pregnancy was associated with asthma, but not rhinitis, eczema or allergic sensitization in the offspring up to 16 years. The association was strongest for persistent asthma, while no increased risk was observed for transient asthma. Categorization of maternal BMI showed that maternal obesity, but not overweight, was significantly associated with childhood asthma. However, the child’s own weight status could partly explain the observed association between maternal BMI and asthma in the offspring. In Study II, we found that girls with persistent asthma had a higher BMI and an increased risk of overweight throughout childhood, compared to girls without asthma. Girls with transient asthma had an increased risk of overweight at ages 4-7.9 years, whereas girls with late-onset asthma had a tendency towards an increased risk of overweight at age ≥15 years. In boys, the difference in BMI between children with and without asthma was smaller, and no consistent association was observed between asthma phenotypes and overweight. In Study III, we observed that overweight and obesity at age 8 years were associated with increased forced vital capacity (FVC) and to some extent forced expiratory volume in one second (FEV1), but reduced FEV1/FVC ratios at 8 and 16 years. The strongest association with FEV1/FVC was observed for persistent overweight at both 8 and 16 years, whereas no significant association was found for transient overweight. Cross-sectional analyses of IOS showed that overweight and obesity were associated with higher peripheral airway resistance and reactance at 16 years. The result of Study IV showed that self-reported and measured height and weight were highly correlated at 16 years (r=0.98 for height, r=0.96 for weight). On average, self-reported weight was underreported by 1.1 kg and height was overreported by 0.5 cm, leading to an underestimation of BMI by 0.5 kg/m2. The accuracy of self-reported BMI was somewhat lower among girls and among overweight and obese participants, compared to normal weight participants. Our results suggest that maternal and childhood overweight and obesity are associated with asthma and evidence of airway obstruction in children and adolescents. The association between maternal BMI and asthma may, to some extent, be mediated through childhood overweight and seems to be explained by non-allergic mechanisms. In addition, we conclude that web-based self-reported BMI can be used as a valid, quick and cost-effective alternative to measured BMI among Swedish adolescents. The accuracy however declines with increasing BMI, and is somewhat lower among girls compared to boys

Impact of ocean acidification on antimicrobial activity in gills of the blue mussel (Mytilus edulis)

Here, we aimed to investigate potential effects of ocean acidification on antimicrobial peptide (AMP) activity in the gills of Mytilus edulis, as gills are directly facing seawater and the changing pH (predicted to be reduced from 8.1 to 7.7 by 2100). The AMP activity of gill and haemocyte extracts was compared at pH 6.0, 7.7 and 8.1, with a radial diffusion assay against Escherichia coli. The activity of the gill extracts was not affected by pH, while it was significantly reduced with increasing pH in the haemocyte extracts. Gill extracts were also tested against different species of Vibrio (V. parahaemolyticus Vibrio tubiashii, V. splendidus and V. alginoyticus) at pH 7.7 and 8.1. The metabolic activity of the bacteria decreased by 65-90%, depending on species of bacteria, but was, as in the radial diffusion assay, not affected by pH. The results indicated that AMPs from gills are efficient in a broad pH-range. However, when mussels were pre-exposed for pH 7.7 for four month the gill extracts presented significantly lower inhibit of bacterial growth. A full in-depth proteome investigation of gill extracts, using LC-Orbitrap MS/MS technique, showed that among previously described AMPs from haemocytes of Mytilus, myticin A was found up-regulated in response to lipopolysaccharide, 3 h post injection. Sporadic occurrence of other immune related peptides/proteins also pointed to a rapid response (0.5?3 h p.i.). Altogether, our results indicate that the gills of blue mussels constitute an important first line defence adapted to act at the pH of seawater. The antimicrobial activity of the gills is however modulated when mussels are under the pressure of ocean acidification, which may give future advantages for invading pathogens

The Swedish CArdioPulmonary BioImage Study : objectives and design

Cardiopulmonary diseases are major causes of death worldwide, but currently recommended strategies for diagnosis and prevention may be outdated because of recent changes in risk factor patterns. The Swedish CArdioPulmonarybioImage Study (SCAPIS) combines the use of new imaging technologies, advances in large-scale 'omics' and epidemiological analyses to extensively characterize a Swedish cohort of 30 000 men and women aged between 50 and 64 years. The information obtained will be used to improve risk prediction of cardiopulmonary diseases and optimize the ability to study disease mechanisms. A comprehensive pilot study in 1111 individuals, which was completed in 2012, demonstrated the feasibility and financial and ethical consequences of SCAPIS. Recruitment to the national, multicentre study has recently started.Funding agencies:  Swedish Heart and Lung Foundation; Knut and Alice Wallenberg Foundation; Swedish Research Council; VINNOVA (Swedens innovation agency)</p