Diabetes mellitus and the risk of sudden cardiac death: A systematic review and meta-analysis of prospective studies

Although diabetes mellitus is an established risk factor for myocardial infarction and stroke, data on the association with sudden cardiac death are less extensive and the findings have not been entirely consistent. We therefore conducted a systematic review and meta-analysis of prospective studies on diabetes mellitus and risk of sudden cardiac death. PubMed and Embase databases were searched up to July 18th 2017. Prospective studies that reported adjusted relative risk (RR) estimates and 95% confidence intervals (CIs) for the association between a diabetes diagnosis or pre-diabetes and risk of sudden cardiac death were included. Summary RRs were estimated by use of a random effects model. Nineteen population-based prospective studies (11 publications) (3610 cases, 249,225 participants) and 10 patient-based prospective studies (2713 cases, 55,098 participants) were included. The summary RR for diabetes patients vs. persons without diabetes was 2.02 (95% CI: 1.81–2.25, I2 = 0%, pheterogeneity = 0.91) in the population-based studies. The summary RR was 1.23 (95% CI: 1.05–1.44, I2 = 6%, pheterogeneity = 0.34) for the association between pre-diabetes and sudden cardiac death (n = 3 studies, 1000 sudden cardiac deaths, 18,360 participants). In the patient-based studies, the summary RR of sudden cardiac death for diabetes patients vs. patients without diabetes was 1.75 (95% CI: 1.51–2.03, I2 = 39%, pheterogeneity = 0.10) for all patients combined, 1.63 (95% CI: 1.36–1.97, I2 = 39%, n = 5) for coronary heart disease patients, and 1.85 (95% CI: 1.48–2.33, I2 = 0%, n = 3) for heart failure patients. These results suggest that diabetes patients are at an increased risk of sudden cardiac death both in the general population and among different patient groups. •Data regarding diabetes mellitus and sudden cardiac death is not as extensive as for myocardial infarction.•A meta-analysis was conducted of 19 population-based studies and 10 patient-based studies.•Diabetes mellitus was associated with a 2-fold increase in the risk of sudden cardiac death in the general population.•Diabetes mellitus was associated with a 75% increase in the risk of sudden cardiac death in the patient-based studies.•Pre-diabetes was associated with a 23% increase in the risk.