1. From Gaubius Laboratory, TNO Quality of Life, Leiden, the Netherlands (A.S., M.R.d.V., C.J.v.L., J.M.G., P.H.A.Q.); Department of Vascular Surgery, Leiden University Medical Centre, Leiden, the Netherlands (A.S., J.H.v.B.); Department of Renal Diseases, Leiden University Medical Centre, Leiden, the Netherlands (M.R.D.); and Department of Rheumatology, University of Colorado Health Sciences Center, Denver (V.M.H.).