Diabetes and sudden cardiac death: a Danish nationwide study

Diabetes mellitus is associated with increased risk of sudden cardiac death (SCD). However, nationwide, unselected studies are lacking. Therefore, this study aimed to estimate the incidence rates of SCD among individuals with Type 1 diabetes (T1D) and Type 2 diabetes (T2D) and to quantify the shortened life expectancy that can be attributed to SCD.

The study included the entire Danish population in 2010. Sudden cardiac death cases were identified through the detailed Danish death certificates, and discharge summaries, and if performed, autopsy reports. Cox proportional hazards models were used to estimate risk of SCD in diabetes patients. Loss of life years was estimated for both T1D and T2D patients.

Among the identified 6862 SCD cases, 97 were diagnosed with T1D and 1149 with T2D. Incidence rates of SCD were 3.7 times higher for T1D and 6.5 times higher for T2D compared with the general population. After multivariable adjustment, both T1D and T2D were independently associated with SCD. The greatest risk difference was observed in younger individuals with diabetes. Life-years lost were on average 14.2 and 7.9 years shorter for patients with T1D and T2D, respectively. A reduced life expectancy of 3.4 and 2.7 years was found to be attributed to SCD for T1D and T2D, respectively.

Individuals with diabetes displayed consistently elevated incidence rates of SCD across age groups. Further, the elevated risk of SCD in individuals with diabetes diminished with increasing age. For both T1D and T2D, SCD was an important contributing factor to shortened life expectancy.