1. Department of Physiology, Faculty of Medical Sciences, Zabrze, Medical University of Silesia, Katowice, Poland
2. Department of Internal Medicine, Diabetology and Nephrology, Zabrze, Medical University of Silesia, Katowice, Poland
3. Department of Internal Medicine and Geriatrics, Jagiellonian University Medical College, Krakow, Poland
4. Department of General, Visceral, Transplantation and Vascular Surgery, Hospital of the Ludwig Maximilian University, Munich, Germany