Denmark Study on Diabetes and Atrial Fibrillation

A recent study published in the Journal of Diabetes and its Complications has found an increased hazard of developing atrial fibrillation (AF) with increasing levels of haemoglobin A1c (HbA1c). People with new diabetes onset and those with known diabetes had similar hazard of AF development; however, people with known diabetes had a significantly higher hazard of stroke, cardiovascular mortality, and mortality from all causes.

The study findings may contribute to the development of strategies for preventing atrial fibrillation development in both individuals with dysglycemia and those with overt diabetes. Atrial fibrillation and diabetes are two key non-communicable chronic diseases of modern times. Diabetes is the most common metabolic disorder in the world, and its prevalence and increased risk of CVD (cardiovascular disease) and mortality is an increasing global health burden. Atrial fibrillation is the most common arrhythmia, and its prevalence and incidence are expected to increase rapidly in the coming years.

Diabetes is reported to be a risk factor for AF and raises the risk of thromboembolic events in AF patients. However, there is no clarity on the link between the two conditions. Few studies have determined the association between dysglycemia and incident atrial fibrillation. Therefore, Rasmus Rørth, Copenhagen University Hospital, Copenhagen, Denmark, and colleagues investigated the risk of incident AF and prognosis according to diabetes status.

For this purpose, the researchers merged data from the Copenhagen Primary Care Laboratory Database with data on medical prescriptions, in- and outpatient contacts, and vital status. Atrial fibrillation risk according to diabetes risk was investigated using Cox regression models.

Study Findings

• Of 354,807 individuals with a HbA1c measurement, 8% had known diabetes, 4% had new-onset diabetes, and 8% had prediabetes (HbA1c 42-47 mmol/mol).
• Persons with dysglycemia (HbA1c > 42 mmol/mol) and diabetes were older, more were men, they had lower levels of education, and were more likely to be living alone.
• A gradual increase in the risk of developing AF was observed from HbA1c levels of 40 to 60 mmol/mol.
• In adjusted analyses, a stepwise increase was found in the hazard of AF from normoglycemia over prediabetes to persons with diabetes (no diabetes: 1.00; prediabetes: 1.12; new-onset diabetes: 1.16; known diabetes: 1.15).
• Persons with known diabetes had a significantly higher hazard of stroke, cardiovascular, and all-cause mortality.

"Increasing levels of HbA1c in people with HbA1c measurements with ranges from normal to diabetes were associated with an increased hazard of AF development," the researchers wrote. "People with new diabetes onset and people with known diabetes had a similar risk of developing AF, however, persons with known diabetes had a significantly higher hazard of stroke, cardiovascular- and all-cause mortality."

Reference

Rørth, R., Kriegbaum, M., Grand, M. K., Jacobsen, P. K., Lind, B. S., Andersen, C. L., & Persson, F. (2023). Risk of atrial fibrillation in individuals with dysglycemia and diabetes. Journal of Diabetes and its Complications, 37(9), 108579. https://doi.org/10.1016/j.jdiacomp.2023.108579