作者单位:Univ Calif San Francisco, Dept Med, Div Nephrol, San Francisco, CA 94143 USA[1]Univ Calif San Francisco, Dept Epidemiol & Biostat, San Francisco, CA 94143 USA[2]Univ Calif San Francisco, Dept Pediat, Div Pediat Endocrinol, San Francisco, CA 94143 USA[3]Univ Minnesota, Dept Pediat, Div Pediat Nephrol, Minneapolis, MN 55455 USA[4]