1. Department of Gastroenterology, Endocrinology, and Diabetology, Klinikum Lüdenscheid, 58515 Lüdenscheid, Germany
2. Department of Internal Medicine, Medical Clinic C, 67063 Ludwigshafen, Germany
3. Department of Rheumatology, Osteology and Physical Therapy, William G. Kerckhoff Foundation, Justus Liebig University Giessen, 35385 Giessen, Germany