[1] Kaiser Permanente Los Angeles Med Ctr, Div Nephrol & Hypertens, Los Angeles, CA 90027 USA
[2] Kaiser Permanente So Calif, Dept Res & Evaluat, Pasadena, CA USA
[3] Harbor UCLA Med Ctr, Harold Simmons Ctr Kidney Dis Res & Epidemiol, Torrance, CA 90509 USA
[4] Univ Alabama, Dept Cardiovasc Med, Birmingham, AL USA