1. From Bioengineering and Chronobiology Laboratories, University of Vigo (R.C.H., D.E.A., J.R.F., A.M.), Campus Universitario, Vigo, Spain; and the Hypertension and Vascular Risk Unit, Hospital Clínico Universitario (C.C., J.E.L., M.J.D., M.C.), Santiago de Compostela, Spain.