[1] Hosp Univ Clin San Carlos, Dept Nephrol, E-28040 Madrid, Spain
[2] Hosp Univ Clin San Carlos, Dept Endocrinol, E-28040 Madrid, Spain
[3] Hosp Univ Clin San Carlos, Dept Gen Med, E-28040 Madrid, Spain
[4] Hosp Univ Clin San Carlos, Dept Pathol, E-28040 Madrid, Spain