Declining burden of sudden cardiac death in young individuals with diabetes
T Skjelbred, U Pedersen-Bjergaard, L Koeber, E Paratz, B G Winkel, T H Lynge, J Tfelt-HansenAbstract
Background
Individuals with diabetes mellitus are at elevated risk of sudden cardiac death (SCD). Whether improvements in diabetes care have translated into declining SCD incidence rates over time remains unclear.
Objective
To assess temporal trends in SCD incidence rates among Danish individuals aged 1–49 years, with and without diabetes, between 2007 and 2019.
Methods
Using nationwide registry data, we constructed a dynamic cohort including all Danish residents aged 1–49 years from 2007 to 2019. Diabetes status was treated as a time-varying exposure defined by the first recorded diagnosis or prescription for glucose-lowering therapy. Participants contributed person-time to the non-diabetic and diabetic states accordingly. SCD cases were adjudicated based on death certificates, autopsy reports, and other medical documentation. Annual incidence rates per 100 000 person-years were estimated, and Poisson regression models were used to calculate the annualized percentage change (APC) and incidence rate ratios (IRRs) with 95% confidence intervals (CIs). Linear regression models estimated absolute annual changes in SCD incidence.
Results
Over 13 years of follow-up, 45 million person-years and 2 764 SCD events were recorded. In 2007, SCD incidence was 117 per 100 000 person-years among individuals with diabetes and 8.5 per 100 000 among those without; by 2019, these had declined to 40.0 and 4.0 per 100 000 person-years, respectively. The APC was –5.9% (95% CI –6.9 to –4.9) for non-diabetic and –6.6% (95% CI –9.3 to –3.9) for diabetic individuals. The IRR between groups did not change significantly, indicating similar relative declines. However, the absolute annual decrease in SCD rates was significantly greater among those with diabetes (–3.7 [95% CI –6.5 to –1.0] per 100 000 person-years annually).
Conclusion
Between 2007 and 2019, SCD incidence declined substantially in Danes under 50 years, both with and without diabetes. Despite similar relative declines, individuals with diabetes maintained a persistently higher SCD risk. However, the greater absolute decline among individuals with diabetes indicates that, although their relative excess risk of SCD persisted, the absolute burden of SCD in this group decreased more rapidly, likely reflecting improvements in diabetes management and cardiovascular prevention.Figure 1 - Yearly incidence rates of SCDFigure 2 - Yearly incidence rate ratios