INTRODUCTION

Gestational diabetes mellitus (GDM) is variable degree of glucose intolerance that begins or is recognized during pregnancy 1. Pregnant women with GDM have an increased risk of developing type II diabetes mellitus (DM) and cardiovascular disease in long-term follow-ups. Moreover, children of mothers with a history of GDM are at risk of developing obesity and metabolic syndrome in long-term follow-up 2. In addition, some studies have shown subclinical atherosclerosis3, endothelial dysfunction 4, and increased risk of cardiovascular disease in women with a history of GDM5,6. Diabetes also increases arrhythmic events by causing an imbalance in autonomic tone, silent ischemia, heterogeneity in atrial and ventricular repolarization, and direct myocardial damage through increased arrhythmogenic substrates. Atrial fibrillation (AF) is a common arrhythmia in diabetic individuals 7. Electrophysiological and electromechanical delays from intraatrial and interatrial conduction disturbances are associated with an increased risk of AF 8,9. The difference between the maximum P-wave duration (P max) and the minimum P-wave duration (P min) measured noninvasively from a twelve-lead surface electrocardiogram (ECG) is called P-wave dispersion (PWD), and PWD has been found to be closely associated with the development of paroxysmal AF 10. In recent years, the tissue Doppler method has been used to evaluate intraatrial and interatrial conduction times. Atrial EMD measured by this method have been shown to be prolonged in patients with paroxysmal AF11. It has been suggested that atrial conduction times may be disordered in diabetic patients 12. However, as far as we know, atrial conduction times has not been studied in GDM patients. The aim of our study is to investigate PWD and atrial conduction times in patients with GDM.