1. Department of Cardiology and Cardiac Surgery, Military University Hospital No. 10 with a Polyclinic in Bydgoszcz, Bydgoszcz, Poland
2. Department of Hypertension, Medical University of Łódź, Łódź, Poland
3. Department of Clinical Biochemistry, Royal Free Hospital Campus, University College London, London, U.K.
4. Department of Nephrology, Hypertension and Family Medicine, Medical University of Łódź, Łódź, Poland