TPO and hyperthyroidism: As shown in Figure 2, 81/118 (68.6%) subjects had anti-TPO prior to the onset of subclinical/overt hyperthyroidism, 17/118 (14.4%) had anti-TPO parallel to the onset of subclinical/overt hyperthyroidism, 2/118 (1.7%) had anti-TPO following the onset of subclinical/overt hyperthyroidism, and 18/118 (15.3%) had no anti-TPO.