Chronic kidney disease (CKD) is associated with increased risk of cardiovascular disease and mortality as well as impaired quality of life. Participants of this study all have severe CKD, defined as estimated glomerular filtration rate \< 30 ml/min per 1.73 m\^2. Stress ergometry, echocardiography, ultrasound assessment of arterial intima-media thickness, lateral lumbar radiograph, ECG, laboratory tests and quality of life assessment were performed at the baseline of the study and will be repeated during follow-up. Atrial fibrillation and other cardiac arrhythmias as well as pulse wave velocity measurements will be explored. Diet diaries are gathered and analysed. The aim of the study is to identify factors associated with cardiovascular disease, quality of life and mortality in this cohort.
