Mehran Ladan, Amouzegar Atieh, Abdi Hengameh, Delbari Negar, Madreseh Elham, Tohidi Maryam, Mansournia Mohammad Ali, Azizi Fereidoun
Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Eur Thyroid J. 2021 Jul;10(5):390-398. doi: 10.1159/000512665. Epub 2021 Jan 27.
Studies assessing thyroid hormones in metabolic syndrome (MetS) patients are contradictory. Also, the effect of MetS on thyroid function over time is not yet evaluated. This study investigated the prevalence and incidence of thyroid dysfunction (TD) as well as time trends of thyroid hormones in subjects with and without MetS, during a 10-year follow-up in Tehranian adult population.
This is a prospective cohort study conducted in the framework of Tehran Thyroid Study on 5,786 subjects aged ≥20 years: 4,905 eligible participants entered the study after excluding those with corticosteroid or radioactive iodine use, pregnancy, thyrotropin (TSH) <0.1 and >10 mU/L, and missing data. Physical examinations were performed and serum concentrations of TSH, free thyroxine (FT4), thyroid peroxidase antibody (TPOAb), fasting plasma glucose, insulin, and lipid profile were assessed at baseline and 3-year intervals during the follow-up. MetS was defined according to the Joint Interim Statement Definition.
At baseline, there were no difference in median serum concentrations of FT4 and TSH between MetS and non-MetS group after adjusting for age, sex, BMI, smoking, and TPOAb positivity. Although there was higher risk of overt (42%) and subclinical hypothyroidism (16%) in MetS compared with non-MetS subjects, no significant difference was observed in adjusted ORs for any TD between 2 groups. There were also no significant differences in time trends of TSH, FT4, TPOAb positivity, and incidence rates of TDs between MetS and non-MetS groups during 10 years, after adjustment for age, sex, BMI, smoking status, and TPOAb positivity.
MetS is not associated with thyroid hypofunction considering other important confounders such as age, sex, smoking, BMI, and TPOAb positivity. There is also no difference in the trend of thyroid hormones and incidence of TD between MetS and non-MetS subjects during a 10-year follow-up.
评估代谢综合征（MetS）患者甲状腺激素水平的研究结果相互矛盾。此外，MetS对甲状腺功能随时间的影响尚未得到评估。本研究调查了德黑兰成年人群在10年随访期间，患有和未患有MetS的受试者甲状腺功能障碍（TD）的患病率和发病率，以及甲状腺激素的时间趋势。
这是一项前瞻性队列研究，在德黑兰甲状腺研究框架内对5786名年龄≥20岁的受试者进行：排除使用皮质类固醇或放射性碘、妊娠、促甲状腺激素（TSH）<0.1和>10 mU/L以及数据缺失的受试者后，4905名符合条件的参与者进入研究。进行了体格检查，并在基线及随访期间每3年评估一次血清TSH、游离甲状腺素（FT4）、甲状腺过氧化物酶抗体（TPOAb）、空腹血糖、胰岛素和血脂水平。MetS根据联合临时声明定义进行定义。
在调整年龄、性别、BMI、吸烟和TPOAb阳性后，基线时MetS组和非MetS组的FT4和TSH血清中位数浓度没有差异。尽管与非MetS受试者相比，MetS患者发生显性（42%）和亚临床甲状腺功能减退（16%）的风险更高，但两组之间任何TD的调整后比值比均无显著差异。在调整年龄、性别、BMI、吸烟状况和TPOAb阳性后，MetS组和非MetS组在10年期间TSH、FT4、TPOAb阳性的时间趋势以及TD的发病率也没有显著差异。
考虑到年龄、性别、吸烟、BMI和TPOAb阳性等其他重要混杂因素，MetS与甲状腺功能减退无关。在10年随访期间，MetS组和非MetS组之间甲状腺激素趋势和TD发病率也没有差异。
