Researchers have found in a new study that the risk of sudden cardiac arrest (SCA) is highest in individuals with both hypertension and diabetes. However, the association between blood pressure and sudden cardiac arrest is stronger in non-diabetic individuals. In patients with diabetes, both high and low systolic blood pressure are linked to increased sudden cardiac arrest risk, suggesting that preventing hypotension as well as controlling hypertension may be important in this population.Hypertension and diabetes mellitus (DM), including pre-hypertension and impaired fasting glucose (IFG), are associated with increased risk of sudden cardiac arrest (SCA). However, the interaction between hypertension and diabetes mellitus needs further examination. This study utilised data from the South Korean national healthcare insurance system. People who underwent nationwide health screening in 2012 were enrolled. The impact of blood pressure on sudden cardiac arrest was evaluated in both diabetic and non-diabetic patients. Results: A total of 4,593,706 people were analyzed with 3,097,423, 1,034,563, and 461,720 people included in the non-diabetes mellitus, IFG, and DM groups, respectively. Both high blood pressure (systolic, diastolic, and pulse) and DM were associated with an increased risk of sudden cardiac arrest, with the highest absolute risk observed in patients with both conditions. A significant interaction was found between blood pressure and diabetes mellitus (P for interaction <0.01): the relative influence of blood pressure on sudden cardiac arrest risk was greater in the non-diabetic population. Importantly, in diabetic patients, a J-shaped association was observed; not only high but also low systolic blood pressure (<100 mm Hg) was associated with a significantly increased risk of sudden cardiac arrest.Although the risk of sudden cardiac arrest was highest in people with both hypertension and diabetes mellitus, the degree of association between blood pressure and sudden cardiac arrest was more pronounced in non-diabetic people. In patients with diabetes, both high and low systolic blood pressure are associated with an elevated risk of sudden cardiac arrest. While controlling hypertension is crucial for all individuals, avoiding hypotension may be another important strategy for preventing sudden cardiac arrest in the diabetic population.Reference:Kim YG, Lee HS, Seo CO, Kim Y, Jeong JH, Han KD, Shim J, Kim YH, Choi JI. Impact of Blood Pressure on Sudden Cardiac Arrest in Diabetic Patients. Diabetes Metab J. 2026 Mar 6. doi: 10.4093/dmj.2025.0339. Epub ahead of print.Received: Apr 15, 2025; Accepted: Oct 07, 2025. DOI: https://doi.org/10.4093/dmj.2025.0339.