[1] Univ Amsterdam, Acad Med Ctr, Dept Cardiol, NL-1105 AZ Amsterdam, Netherlands
[2] Univ Amsterdam, Acad Med Ctr, Lab Expt Internal Med, NL-1105 AZ Amsterdam, Netherlands
[3] Univ Cambridge, Inst Publ Hlth, Dept Publ Hlth & Primary Care, Cambridge, England
[4] MRC, Dunn Nutr Unit, Cambridge CB4 1XJ, England
[5] Netherlands Red Cross, Blood Transfus Serv, Cent Lab, Sanquin Res, Amsterdam, Netherlands