[1] Lillehammer Hosp Rheumat Dis, Lillehammer, Norway
[2] Univ Oslo, Inst Clin Med, Fac Med, Oslo, Norway
[3] Oslo Univ Hosp, Rikshosp, Dept Rheumatol, Oslo, Norway
[4] Oslo Univ Hosp, Oslo Ctr Biostat & Epidemiol, Res Support Serv, Oslo, Norway
[5] Beitostolen Hlth & Sport Ctr, Beitostolen, Norway
[6] Norwegian Univ Sci & Technol, Gjovik, Norway
[7] Innlandet Hosp Trust, Dept Lab Med, Lillehammer, Norway
[8] Harvard Med Sch, Boston, MA USA
[9] Brigham & Womens Hosp, Div Cardiol, Boston, MA USA
[10] Oslo Univ Hosp, Dept Cardiol, Oslo, Norway