Abstract Body (Do not enter title and authors here): Background:
Patients with type 2 diabetes mellitus (T2DM) often develop atrial fibrillation. Nevertheless, its incidence and long-term cardiovascular outcomes in newly diagnosed atrial fibrillation in patients with T2DM are still unclear.

Hypothesis:
We aim to investigate the association between new-onset AF and the risks of atherosclerotic cardiovascular disease (ASCVD); heart failure (HF), stroke, and all-cause mortality among patients with T2DM.

Methods:
A systematic search was conducted using multiple electronic databases from inception until March 2024 using the appropriate Mesh terms, “atrial fibrillation,” “diabetes mellitus,” “stroke,” “heart failure,” and “all-cause mortality.” We used the random effect model to calculate the pooled relative risk and their corresponding confidence interval. A p-value of <0.05 was considered statistically significant.

Results:
A meta-analysis was piloted using 12 studies. Of these, 10 studies studied DM patients versus non-diabetic (6442051 versus 9572901), and two studies compared atrial fibrillation versus non-atrial fibrillation in DM patients (1521 versus 17560) with a mean follow-up of 9.9 years. Pooled analysis showed that patients with T2DM are more likely to develop AF compared to nondiabetic patients (OR: 1.41, 95%CI: 1.18-1.64, p<0.001). Furthermore, patients with type 2 DM with new-onset atrial fibrillation have an increased of developing HF (OR 3.67, 95% CI 3.07-4.27, p<0.001), stroke (OR 1.79, 95% CI 1.40-2.18, p<0.001), and all-cause mortality (OR 1.70, 95% 1.42-1.98, p<0.001).

Conclusion:
This study reveals that patients with type 2 DM are at increased risk of developing atrial fibrillation compared to nondiabetic patients. Long-term cardiovascular morbidity, such as heart failure, stroke, and all-cause mortality, are also high in patients with type 2 DM with new-onset atrial fibrillation.