Role of Insulin Resistance in the Development of Atrial Fibrillation

Aim: To investigate the relationship between insulin resistance (IR) and atrial fibrillation (AF) in patients without overt diabetes. Materials and Methods: Patients aged >= 18 years without chronic disease other than hypertension were included in the study. Medical histories were obtained, and detailed physical examination, blood tests and electrocardiography were performed. Patients with overt diabetes were excluded from the study. The patients were evaluated in two groups [normal sinus rhythm (NSR) and AF groups]. The presence of IR was analyzed. Results: Two hundred patients (the mean age, 67.33 +/- 8.37 years; 108 females), of whom 132 (66%) had NSR and 68 (34%) had AF, were included in the study. There was no difference between the groups regarding fasting plasma glucose levels (102.65 +/- 7.49 mg/dL and 99.68 +/- 9.46 mg/dL, respectively; p=0.09). A significant difference was found regarding fasting insulin levels (11.06 +/- 2.71 mg/dL and 8.48 +/- 2.64 mg/dL, respectively; p<0.0001). The mean IR [homeostatic model assessment (HOMA-IR)] was significantly higher in the AF group than in the NSR group (2.90 +/- 0.79 and 2.10 +/- 0.46, respectively; p<0.0001). The proportion of patients with IR (HOMA-IR >2.4) was significantly higher in the AF group than in the NSR group (76.47% and 28.78%, respectively; p<0.0001). Regression analyses were performed. Multivariate regression analysis showed that each unit increase in HOMA-IR increased the risk of AF for 2.56 -fold. Conclusion: The main factor for the frequent coexistence of diabetes mellitus and AF was considered to be IR rather than hyperglycemia. Early detection and treatment of IR can reduce AF development and associated morbidity and mortality.