Departamento de Cirurgia e Fisiologia, Unidade de Investigação Cardiovascular, Faculdade de Medicina, Universidade do Porto, Porto, Portugal; Department of Endocrinology, Diabetes and Metabolism, Centro Hospitalar Universitário de São João, Faculdade de Medicina, Universidade do Porto, Porto, Portugal.
Neurology Department, Hospital Prof. Doutor Fernando Fonseca, Amadora, Portugal.
Int J Cardiol. 2019 Jun 15;285:115-120. doi: 10.1016/j.ijcard.2019.03.009. Epub 2019 Mar 6.
Thyroid hormones play a central role in cardiovascular homeostasis. Lower free triiodothyronine (FT3) levels have been associated with worse prognosis in several conditions. However, contrary to thyrotropin (TSH) and free thyroxine (FT4), the role of FT3 in morbidity and mortality in the general population remains uncertain. Our objective was to evaluate the association between within the normal range FT3 levels and mortality in the general population.
We evaluated 7116 adults in the National Health and Nutrition Examination Survey (NHANES) 2001-2002, 2007-2008, and 2009-2010 cycles with mortality evaluated as of December 2011. Exclusion criteria were: pregnancy; history of thyroid disease; use of thyroid-related drugs; and TSH, FT4, or FT3 level outside the reference range.
During a median follow-up of 45 months, 357 participants died. In unadjusted analysis, lower FT3 levels were associated with higher all-cause (HR per 0.1 pg/mL increase in FT3: 0.82 [95% confidence interval, 0.78-0.87]), cardiovascular (HR 0.74 [0.66-0.83]), cancer-related (HR 0.88 [0.80-0.97]) and other cause-related mortality (HR 0.83 [0.77-0.90]). After adjustment with Cox proportional hazard models, lower FT3 levels remained significantly associated with higher cardiovascular mortality (HR 0.83 [0.75-0.93]), but not with all-cause (HR 0.97 [0.92-1.02]), cancer-related (HR 1.02 [0.89-1.17]), or other cause-related mortality (HR 1.00 [0.92-1.10]).
Lower levels of FT3 within the reference range may independently predict higher cardiovascular mortality in the general population.
甲状腺激素在心血管稳态中发挥核心作用。游离三碘甲状腺原氨酸（FT3）水平降低与多种疾病的预后不良有关。然而，与促甲状腺激素（TSH）和游离甲状腺素（FT4）相反，FT3 在普通人群中的发病率和死亡率的作用尚不确定。我们的目的是评估正常范围内 FT3 水平与普通人群死亡率之间的关系。
我们评估了 2001-2002 年、2007-2008 年和 2009-2010 年 NHANES 周期中的 7116 名成年人，截至 2011 年 12 月评估死亡率。排除标准为：妊娠；甲状腺疾病史；使用甲状腺相关药物；以及 TSH、FT4 或 FT3 水平超出参考范围。
在中位随访 45 个月期间，有 357 名参与者死亡。在未调整的分析中，较低的 FT3 水平与全因死亡率（每增加 0.1 pg/mL FT3 的 HR：0.82 [95%置信区间，0.78-0.87]）、心血管死亡率（HR 0.74 [0.66-0.83]）、癌症相关死亡率（HR 0.88 [0.80-0.97]）和其他原因相关死亡率（HR 0.83 [0.77-0.90]）较高相关。在用 Cox 比例风险模型进行调整后，较低的 FT3 水平仍与较高的心血管死亡率显著相关（HR 0.83 [0.75-0.93]），但与全因死亡率（HR 0.97 [0.92-1.02]）、癌症相关死亡率（HR 1.02 [0.89-1.17]）或其他原因相关死亡率（HR 1.00 [0.92-1.10]）无关。
正常范围内较低的 FT3 水平可能独立预测普通人群中较高的心血管死亡率。
