Jun Ji Eun, Jee Jae Hwan, Bae Ji Cheol, Jin Sang-Man, Hur Kyu Yeon, Lee Moon-Kyu, Kim Tae Hyuk, Kim Sun Wook, Kim Jae Hyeon
1 Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine , Seoul, Republic of Korea.
2 Department of Health Promotion, Samsung Medical Center, Sungkyunkwan University School of Medicine , Seoul, Republic of Korea.
Thyroid. 2017 Jan;27(1):29-38. doi: 10.1089/thy.2016.0171. Epub 2016 Dec 9.
Thyroid hormones are important regulators of glucose homeostasis. However, the association between thyroid hormones within the reference range and type 2 diabetes mellitus (T2DM) remains unclear. The aim of this study was to clarify the incidence of T2DM according to the baseline levels and changes of thyrotropin (TSH) and thyroid hormones (free thyroxine and triiodothyronine) in euthyroid subjects.
Among the participants who consecutively underwent thyroid function tests between 2006 and 2012 through a yearly health checkup program, 6235 euthyroid subjects (3619 men and 2616 women) without T2DM were enrolled in the study. The change in each hormone was calculated by subtracting the baseline value from the level at the end of follow-up or one year before the diagnosis of diabetes.
During 25,692 person-years of follow-up, there were 229 new cases of T2DM. After full adjustment for potential confounders including HbA1c and fasting glucose in Cox proportional hazards models, the individuals in the highest tertile of TSH change (2.5-4.2 μIU/mL) had a greater risk of incident T2DM (hazard ratio [HR] = 1.44 [confidence interval (CI) 1.04-1.98], p = 0.027) in comparison with individuals in the lowest tertile (-4.1 to -0.5 μIU/mL). Simultaneously, the highest tertile of triiodothyronine change (16.3-104.7 ng/dL) and free thyroxine change (0.2-1.6 ng/dL) conferred protective effects against diabetes (HR = 0.60 [CI 0.43-0.85], p = 0.002, and HR = 0.34 [CI 0.24-0.48], p < 0.001, respectively) compared with those in the lowest tertile (-76.5 to -1.8 ng/dL and -0.6 to 0.0 ng/dL, respectively). These associations remained significant when each of the hormones was analyzed as a continuous variable. However, baseline levels or tertiles of TSH and thyroid hormones were not associated with the risk of diabetes.
Individual changes in TSH and thyroid hormones, even within the normal reference range, were an additional risk factor of incident T2DM.
甲状腺激素是葡萄糖稳态的重要调节因子。然而，参考范围内的甲状腺激素与2型糖尿病（T2DM）之间的关联仍不清楚。本研究的目的是根据正常甲状腺功能受试者促甲状腺激素（TSH）和甲状腺激素（游离甲状腺素和三碘甲状腺原氨酸）的基线水平及变化情况，阐明T2DM的发病率。
在2006年至2012年通过年度健康检查计划连续接受甲状腺功能检查的参与者中，纳入6235名无T2DM的正常甲状腺功能受试者（3619名男性和2616名女性）。每种激素的变化通过随访结束时或糖尿病诊断前一年的水平减去基线值来计算。
在25692人年的随访期间，有229例新的T2DM病例。在Cox比例风险模型中对包括糖化血红蛋白（HbA1c）和空腹血糖在内的潜在混杂因素进行全面调整后，TSH变化最高三分位数（2.5 - 4.2 μIU/mL）的个体发生T2DM的风险更高（风险比[HR]=1.44[置信区间（CI）1.04 - 1.98]，p = 0.027），而最低三分位数（-4.1至-0.5 μIU/mL）的个体相比则较低。同时，三碘甲状腺原氨酸变化最高三分位数（16.3 - 104.7 ng/dL）和游离甲状腺素变化最高三分位数（0.2 - 1.6 ng/dL）对糖尿病具有保护作用（HR分别为0.60[CI 0.43 - 0.85]，p = 0.002和HR为0.34[CI 0.24 - 0.48]，p < 0.001），相比最低三分位数（分别为-76.5至-1.8 ng/dL和-0.6至0.0 ng/dL）。当将每种激素作为连续变量进行分析时，这些关联仍然显著。然而，TSH和甲状腺激素的基线水平或三分位数与糖尿病风险无关。
TSH和甲状腺激素的个体变化，即使在正常参考范围内，也是新发T2DM的一个额外风险因素。
