[1] Columbia Univ, Coll Phys & Surg, Celiac Dis Ctr, New York, NY 10032 USA
[2] Columbia Univ, Mailman Sch Publ Hlth, Dept Epidemiol, New York, NY 10032 USA
[3] Columbia Univ, Mailman Sch Publ Hlth, Dept Biostat, New York, NY 10032 USA
[4] Columbia Univ, Div Endocrinol, Dept Med, Coll Phys & Surg, New York, NY 10032 USA