Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, I. R. Iran.
Prevention of Metabolic Disorders Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, I. R. Iran.
Horm Metab Res. 2019 Jun;51(6):347-352. doi: 10.1055/a-0887-6213. Epub 2019 Jun 17.
Various cut-offs have been proposed for thyroid peroxidase antibodies (TPOAb) positivity. Considering that the long-term trend of TPOAb levels and its positivity incidence is not clearly understood, we conducted the current study to determine the longitudinal variations of TPOAb in a population-based cohort study. We followed 5783 individuals of Tehran Thyroid cohort Study (TTS) for 10 years (4 phases). After exclusions, data of 3493 euthyroid participants remained for analyses. The baseline prevalence rates of TPOAb positivity were 19.8, 17, and 11.4% and the annual incidence rates (95% CI) of TPOAb positivity were 8.53 (8.29-8.77), 7.59 (7.37-7.80) and 6.79 (6.60-6.98) per 1000 persons for the 3 proposed cut-offs of 14.77, 18.38, and 40 U/l; respectively. Although a slightly increasing trend was observed for TPOAb levels (p=0.001) and its conventional positivity (TPOAb>40U/l), the recently proposed cut-offs of 14.77 and 18.38 U/l showed constant TPOAb positivity over 10 years. The time trends of the TPOAb levels among younger participants were significantly different from older participants (time×age effect p=0.004), with the former having an increasing trend and the latter, a relatively decreasing trend. Although the prevalence of TPOAb positivity was significantly (p<0.001) higher among women as compared to men, the longitudinal changes of TPOAb were similar in men and women. TPOAb positivity along with TSH values between 2.5 and 5.0 mU/l or free T4 values between 0.93 and 1.7 ng/dl exerted a significantly increased risk of subclinical or overt hypothyroidism. In an iodine sufficient population, an increasing trend in TPOAb levels was observed in line with the increasing incidence of subclinical and overt hypothyroidism.
各种甲状腺过氧化物酶抗体（TPOAb）阳性的截断值已经被提出。由于 TPOAb 水平的长期趋势及其阳性发生率尚不清楚，我们进行了这项基于人群的队列研究，以确定 TPOAb 的纵向变化。我们对 5783 名德黑兰甲状腺队列研究（TTS）的个体进行了 10 年（4 个阶段）的随访。排除后，3493 名甲状腺功能正常的参与者的数据仍可用于分析。TPOAb 阳性的基线患病率分别为 19.8%、17%和 11.4%，在三个建议的截断值（14.77、18.38 和 40U/l）下，TPOAb 阳性的年发病率（95%CI）分别为 8.53（8.29-8.77）、7.59（7.37-7.80）和 6.79（6.60-6.98）/1000 人。尽管 TPOAb 水平（p=0.001）及其常规阳性（TPOAb>40U/l）呈略有上升趋势，但最近提出的 14.77 和 18.38U/l 的截断值显示 10 年内 TPOAb 阳性率保持不变。年轻参与者的 TPOAb 水平的时间趋势与老年参与者明显不同（时间×年龄效应 p=0.004），前者呈上升趋势，后者呈相对下降趋势。尽管 TPOAb 阳性率在女性中明显高于男性（p<0.001），但 TPOAb 的纵向变化在男性和女性中相似。TPOAb 阳性与 TSH 值在 2.5 和 5.0mU/l 之间或游离 T4 值在 0.93 和 1.7ng/dl 之间的患者亚临床或显性甲状腺功能减退症的风险显著增加。在碘充足的人群中，TPOAb 水平呈上升趋势，与亚临床和显性甲状腺功能减退症的发病率增加一致。
