Hypertension has emerged as a second, after diabetes mellitus, most frequent cause of chronic kidney disease (CKD). The rise of arterial blood pressure and endothelial damage due to ischaemia during apneic episodes may contribute to CKD. According to the recent findings OSA patients are much more frequently diagnosed with chronic kidney disease. The high frequency of OSA in patients with renal function impairment could be explained by the fact that the most common comorbid conditions of CKD, namely atherosclerosis and diabetes, are also independently associated with his syndrome. The detailed pathogenesis of the strong relation between OSA and CKD has not been investigated so far.