Asthma, type 1 diabetes co-aggregate within families

  • Smew AI & al.
  • JAMA Netw Open
  • 2 Mar 2020

  • curated by Miriam Davis, PhD
  • Clinical Essentials
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Takeaway

  • Asthma and type 1 diabetes (T1D) co-occur within individual children, according to a large Swedish cohort study. 
  • Asthma is associated with increased T1D risk, but not vice versa.
  • Siblings are also at risk for co-occurrence.

Why this matters

  • Clinicians should maintain a high index of suspicion for familial co-aggregation when either disease presents in a child.

Study design

  • Retrospective cohort study of 1,284,748 singleton children, live-born in Sweden (2001-2013).
  • Children were linked to their biological full siblings, cousins, and half-cousins.
  • Funding: Swedish Research Council; others.

Key results

  • Asthma occurred in 9.5%, T1D in 0.3%.
    • 494 (0.04%) had both conditions.
  • Asthma and T1D were positively associated within an individual child.
    • OR, 1.15 (95% CI, 1.05-1.27).
  • Children with asthma had a higher risk for subsequent T1D.
    • HR, 1.16 (95% CI, 1.06-1.27).
  • Children with T1D did not have a higher risk for asthma.
    • HR, 0.92 (95% CI, 0.75-1.12).
  • Siblings of children with 1 condition were at increased risk for the other.
    • OR, 1.27 (95% CI, 1.13-1.42).
  • Full cousins of children with 1 disease were at marginally increased risk for the other.
    • OR, 1.08 (95%CI, 1.00-1.17).

Limitations

  • No information on primary care diagnoses.