In case of hypothyroidism, the time interval between RAI and initiation of L-T4 was similar in TPO Ab-positive patients compared to TPO Ab-negative patients (median, 60 days (Q1, 46 : Q3, 102) vs 76 days (Q1, 47 : Q3, 132); P  = 0.193). This evidence concerns the gene TPO and hypothyroidism.