Congenital heart defects are linked to T1D risk

  • Björk A & al.
  • Int J Cardiol
  • 10 Jan 2020

  • curated by Miriam Tucker
  • Clinical Essentials
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Takeaway

  • Type 1 diabetes (T1D) risk is 50% greater among adults with congenital heart defects (CHDs) born during 1970-1984.
  • Mortality was 4-fold higher among individuals with both CHD and T1D vs T1D alone.

Why this matters

  • About 1% liveborn children have CHD, and >95% reach adulthood.
  • T1D is an autoimmune disease, arising after various triggers.

Study design

  • From Swedish National Patient Registry: 21,982 adults with CHD were matched with controls for sex, county, and year of birth, and followed to a maximum of 42 years.
  • Funding: Swedish Heart-Lung Foundation; Swedish state.

Key results

  • T1D was diagnosed in 1% with CHD vs 0.7% controls.
    • Incidence rates: 3.7 vs 2.5 per 10,000 person-years.
    • HR, 1.50 (95% CI, 1.3-1.73).
  • By birth cohort, T1D risk among those with vs without CHD: 
    • 1970-1984: 3.7 vs 2.0 per 10,000 person-years;
      • HR, 1.9 (95% CI, 1.55-2.24). 
    • 1985-1993: 3.8 vs 3.3 per 10,000 person-years;
      • HR, 1.14 (95% CI, 0.9-1.41; no increased risk).
  • Vs controls, HRs (95% CIs) for mortality:
    • CHD alone: 16.19 (15.00-17.48). 
    • Following T1D onset: 4.21 (2.40-7.37). 
    • 2414 (CHD alone) vs 543 (with T1D) per 10,000 person-years.
  • Birth cohort mortality risk (HRs; 95% CIs) with CHD+T1D:
    • 1970-1984: 4.06 (2.21-7.47). 
    • 1985-1993: 5.18 (1.24-21.72).

Limitations

  • Retrospective design.
  • Original medical records unavailable.
  • Possible diabetes type misdiagnosis.
  • Shorter follow-up time in younger group.