[1] Johns Hopkins Univ, Sch Med, Div Endocrinol, Johns Hopkins Bayview Med Ctr,Dept Med, Baltimore, MD 21224 USA
[2] Univ Virginia, Ctr Publ Hlth Genom, Div Biostat & Epidemiol, Charlottesville, VA USA
[3] Univ Virginia, Dept Publ Hlth Sci, Div Biostat & Epidemiol, Charlottesville, VA USA
[4] Univ Miami, Miller Sch Med, John P Hussman Inst Human Genom, Dr John T Macdonald Fdn Dept Human Genet, Miami, FL 33136 USA
[5] Wake Forest Univ, Dept Internal Med, Sch Med, Winston Salem, NC 27109 USA
[6] Johns Hopkins Bloomberg Sch Publ Hlth, Dept Epidemiol, Baltimore, MD USA