[1] Univ Autonoma Barcelona, Dept Nephrol, E-08193 Barcelona, Spain
[2] Univ Autonoma Barcelona, Dept Clin Biochem, E-08193 Barcelona, Spain
[3] Univ Autonoma Barcelona, Hosp Germans Trias & Pujol, Stat Consulting UAB, E-08193 Barcelona, Spain
[4] Univ Autonoma Barcelona, Dept Endocrinol, E-08193 Barcelona, Spain