TPO and hypothyroidism: As shown in Figure 1, 111/152 (73.0%) subjects had anti-TPO prior to the onset of subclinical/overt hypothyroidism, 21/152 (13.8%) had anti-TPO parallel to the onset of subclinical/overt hypothyroidism, 1/152 (0.7%) had anti-TPO following the onset of subclinical/overt hypothyroidism, and 19/152 (12.5%) had no anti-TPO.