[1] Oslo Univ Hosp, Dept Nucl Med, Div Radiol & Nucl Med, Oslo, Norway
[2] Univ Oslo, Fac Med, Inst Clin Med, Oslo, Norway
[3] Univ Oslo, Fac Med, Inst Hlth & Soc, Oslo, Norway
[4] Oslo Univ Hosp, Dept Geriatr Med, Oslo, Norway
[5] Vestfold Hosp Trust, Norwegian Natl Advisory Unit Ageing & Hlth, Tonsberg, Norway
[6] Norwegian Inst Publ Hlth, Dept Chron Dis & Ageing, Oslo, Norway
[7] Univ Oslo, Dept Phys, Oslo, Norway