1. Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
2. Interdisciplinary Center Psychopathology and Emotion Regulation, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
3. Department of Epidemiology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
4. Department of Laboratory Medicine, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
5. FrieslandCampina, Amersfoort, the Netherlands