[1] Tufts Univ, Biol Program, Medford, MA 02155 USA
[2] Tufts Univ, Community Hlth Program, Medford, MA 02155 USA
[3] Massachusetts Gen Hosp, Ctr Diabet, Boston, MA 02114 USA
[4] Harvard Univ, Sch Med, Boston, MA USA
[5] Univ N Carolina, Div Gen Internal Med & Clin Epidemiol, Chapel Hill, NC USA
[6] Massachusetts Gen Hosp, Div Gen Internal Med, Boston, MA 02114 USA