1. Department of Metabolic Diseases, Jagiellonian University Medical College, Krakow, Poland.
2. Department of Internal Medicine, Diabetology and Nephrology, Medical University of Silesia, Katowice, Poland.
3. Department of Pediatrics, Diabetology and Endocrinology, Medical University of Gdansk, Poland.
4. Department of Internal Medicine and Diabetology, Poznan University of Medical Science, Poland.