{
  "abstract": "Background Bronchiolitis is associated with asthma persisting until adulthood. While bronchial hyper-reactivity (BHR) is a hallmark of asthma, its occurrence and characteristics after bronchiolitis have been less studied. We aimed to study if BHR differed between young adults hospitalised for bronchiolitis in infancy and control subjects with no such history. Further, we sought to study whether any association between asthma and BHR differed between these two groups.Methods This Norwegian historical cohort study included 186 young adults hospitalised for respiratory syncytial virus positive or negative bronchiolitis in infancy during 1996–2001 and 139 matched control subjects. BHR was assessed at 17–20 years by methacholine provocation tests and recorded as dose–response slopes (DRS). Outcomes were analysed by mixed effects regression models.Results DRS was higher in the post-bronchiolitis group than in the control group (regression coefficient (β) 0.37; 95% CI 0.01 to 0.73; p=0.045). In both groups combined, current asthma was positively associated with DRS (β 0.98; 95% CI 0.50 to 1.45; p<0.001). Stratified analyses showed that the effect (β) of asthma on BHR was 0.80 (95% CI 0.21 to 1.38; p=0.008) in the post-bronchiolitis group and 1.40 (95% CI 0.58 to 2.23; p=0.001) in the control group. The difference in the association between asthma and BHR across the two groups was not statistically significant (p=0.191 for interaction).Conclusions BHR at age 17–20 years was higher in subjects hospitalised for bronchiolitis in infancy than in control subjects. The association between asthma and BHR was not found to differ between the post-bronchiolitis group and the control group, although a possible stronger association in the control group may warrant further study.",
  "authors": [
    {
      "affiliations": [
        "Department of Paediatrics, Stavanger University Hospital, Stavanger, Norway",
        "Department of Clinical Science, University of Bergen, Bergen, Norway"
      ],
      "name": "Karen Galta Sørensen"
    },
    {
      "affiliations": [
        "Department of Paediatrics, Stavanger University Hospital, Stavanger, Norway",
        "Department of Clinical Science, University of Bergen, Bergen, Norway"
      ],
      "name": "Knut Øymar"
    },
    {
      "affiliations": [
        "Department of Research, Stavanger University Hospital, Stavanger, Norway"
      ],
      "name": "Ingvild Dalen"
    },
    {
      "affiliations": [
        "Department of Clinical Science, University of Bergen, Bergen, Norway",
        "Department of Sports Medicine, Norwegian School of Sports Sciences, Oslo, Oslo, Norway"
      ],
      "name": "Thomas Halvorsen"
    },
    {
      "affiliations": [
        "Department of Paediatrics, Stavanger University Hospital, Stavanger, Norway",
        "Department of Clinical Science, University of Bergen, Bergen, Norway"
      ],
      "name": "Ingvild Bruun Mikalsen"
    }
  ],
  "title": "Bronchial hyper-reactivity in young adults after hospitalisation for bronchiolitis in infancy",
  "uid": "96963e78-d9d1-5029-a68a-63891c281818"
}