Bold claim upfront: diabetes dramatically elevates the risk of sudden cardiac death (SCD) and steals years from life, even in people who seem otherwise healthy. A comprehensive Danish nationwide study lays this bare, showing that both type 1 diabetes (T1D) and type 2 diabetes (T2D) are linked with markedly higher SCD rates and shorter lifespans. The findings underscore the urgent need to identify and shield individuals most vulnerable to cardiac events.
What the study found
SCD is an unforeseen cessation of heart function, often due to an electrical disturbance in the heart. Past research has pointed out that many SCD cases occur in people without previously known heart disease. This study adds a critical dimension by quantifying how diabetes itself influences SCD risk and the corresponding loss of life expectancy.
Key results include:
- People with diabetes die from SCD at higher rates than the general population. Specifically, the incidence rate (IR) of SCD is 394 per 100,000 person-years for T1D and 681 per 100,000 for T2D, compared with 105 per 100,000 in the general population. The relative burden is especially pronounced in younger ages, with T1D patients aged 30–40 years facing about 22.7 times higher risk than peers without diabetes.
- Life expectancy is shortened for people with diabetes. A 30-year-old with T1D is expected to live about 14.2 fewer years than a non-diabetic counterpart, with 3.4 of those years attributable to SCD. For a 30-year-old with T2D, the deficit is about 7.9 years overall, with 2.7 years due to SCD. The gap diminishes with increasing age.
- Diabetes brings a heavier burden of cardiovascular and non-cardiovascular conditions. Among SCD cases with diabetes, there are higher rates of ischemic heart disease, heart failure, arrhythmias, and cardiomyopathy, along with kidney, lung, nerve, liver, and mental health comorbidities. A notable portion of these diabetes-related SCD cases had prior hospitalizations for hypoglycemia, pointing to potential contributing factors.
How the analysis was done
The study used a nationwide Danish cohort, covering all residents alive on January 1, 2010, and tracked until December 31, 2010. For those who died, researchers reviewed death certificates, discharge summaries, and, when available, autopsy reports. Independent physician reviews resolved any disagreements about whether deaths were truly sudden. Diabetes status was linked from national registries to identify T1D and T2D cases, with reasonable sensitivity and very high specificity.
Demographic context and interpretation
In 2010, Denmark’s population stood at about 5.5 million, with 54,028 total deaths that year. Among these, roughly 14.1% were classified as sudden deaths, and 12.7% as SCD. The diabetes cohorts included about 25,020 individuals with T1D and 172,669 with T2D, yielding 97 and 1,149 SCD cases respectively. Compared with the general population, those with diabetes tended to be older and more frequently male.
Clinical implications and questions for the future
The study reinforces the importance of proactive cardiovascular risk management in people with diabetes, including strategies that extend beyond those with established heart disease. It also raises important questions: Why is the relative risk of SCD especially high in younger individuals with T1D? How might better glycemic control, hypoglycemia prevention, and personalized monitoring reduce SCD risk? And what role do non-cardiovascular comorbidities play in driving the overall risk?
If this topic resonates, consider discussing in the comments how your healthcare team could better address SCD risk in younger people with diabetes, or what kinds of screening and lifestyle interventions you believe would make the most difference.
Journal reference:
Skjelbred, T. et al. (2025) Diabetes and sudden cardiac death: a Danish nationwide study. European Heart Journal. 1–13. DOI: 10.1093/eurheartj/ehaf826
