1. From the Department of Medicine and Surgery, Clinica Medica, University of Milano-Bicocca, Italy (G.G., G.S., F.Q.-T.)
2. Consiglio Nazionale delle Ricerche-Istituto di Fisiologia Clinica, Clinical Epidemiology and Physiopathology of Renal Diseases and Hypertension, Reggio Calabria, Italy (A.P., D.B., G.D., F.M., C.Z.)
3. Department of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy (G.M.).