1. Department of Internal Medicine, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels, Belgium
2. Department of Gastro-Enterology, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels, Belgium
3. Laboratory of Hormonology and Tumor Markers, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels, Belgium
4. Department of Biomedical Statistics and Informatics, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels, Belgium
5. Department of Endocrinology, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels, Belgium