1. Drammen Hospital Department of Rheumatology, , N-3004 Drammen, Norway
2. Morbid Obesity and Preventive Medicine, Oslo University Hospital Department of Endocrinology, , 0424 Oslo, Norway
3. University of Aarhus Faculty of Medicine, , 8000 Aarhus, Denmark
4. Spesialistsenteret Pilestredet Park , 0176 Oslo, Norway
5. University of Oslo Faculty of Dentistry, , 1142 Blindern, Oslo, Norway