2193-P: The Role of Diabetes in the Relationship between Muscle Strength and Atrial Fibrillation

Introduction and Objective: Diabetes is an established risk factor for incident atrial fibrillation (AF). In addition, diabetes and reduced muscle strength have been shown to be mutual risk factors. We recently identified low muscle strength as a novel risk factor for incident AF. Based on the hypothesis that diabetes may be involved in this association, this study examined the relationship between relative grip strength and incident AF and evaluated the mediating role of incident diabetes. Methods: We analyzed 98,006 adults aged 18-91 years (60,405 men) without diabetes or AF who underwent health checkups with grip strength testing. Baseline RGS was calculated as grip strength-body weight ratio, and participants were followed for diabetes and AF. Cox models incorporating incident diabetes as a time-dependent covariate were used. Results: The mean age was 47.9 ± 9.5 years, with a mean follow-up of 7.2 ± 3.3 years. During follow-up, 5.0% developed diabetes and 0.6% developed AF. Participants were categorized into sex-specific RGS quartiles. Compared with the highest quartile, the lowest quartile had a higher risk of AF (hazard ratio [HR] 1.50; 95% confidence interval [CI] 1.15-1.97). Adjustment for time-dependent incident diabetes did not attenuate this association. Conclusion: Lower relative grip strength was associated with incident AF independently of incident diabetes, suggesting that reduced muscle strength may contribute to AF development through mechanisms distinct from diabetes.