Department of Medicine and Surgery, Endocrinology of Aging Unit, University Hospital of Parma, Via Gramsci, 14-43126, Parma, Italy.
Critical Care Unit, University of Parma, Parma, Italy.
Aging Clin Exp Res. 2019 Mar;31(3):385-391. doi: 10.1007/s40520-018-0975-0. Epub 2018 May 29.
Thyroid hormone variation may be correlated with adverse health outcomes, even within the normal reference range in euthyroid individuals.
To determine the association between plasma thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) levels and physical performance score in middle age and older adults who had levels of all three hormones in the normal range.
In this community-based, cross-sectional study, euthyroid participants of the Invecchiare in Chianti study, aged 23-102 years (N = 1060), were considered. Physical performance was evaluated by the Summary Physical Performance Battery (SPPB) score. Plasma TSH, FT3, and FT4 levels were predictors, and SPPB score was the outcome.
At the univariate analyses, TSH, FT4, and FT3 were not significantly associated with SPPB score in young individuals, whereas, in older participants, SBBP score was positively (P < 0.001) associated with FT3, and negatively associated with both TSH (P < 0.02) and FT4 (P < 0.001). After adjusting for multiple confounders, FT3 remained significantly associated with SPPB (beta ± SE, 0.35 ± 0.17, P = 0.04), but FT4 and TSH were not. Results did not change when all the three hormones FT3, FT4, and TSH were simultaneously considered in the fully adjusted model (beta ± SE for FT3, 0.37 ± 0.18, P = 0.04).
The results of this study demonstrate that SPPB score is positively associated with circulating FT3 but not with FT4 or with TSH, in older euthyroid individuals.
In euthyroid older adults, circulating FT3 may play an important role in the thyroid effects on physical function.
甲状腺激素的变化可能与不良健康结果相关，即使在甲状腺功能正常的个体的正常参考范围内也是如此。
确定甲状腺刺激激素（TSH）、游离三碘甲状腺原氨酸（FT3）和游离甲状腺素（FT4）水平与中年及以上甲状腺功能正常个体的身体表现评分之间的关系。
在这项基于社区的横断面研究中，考虑了 Invecchiare in Chianti 研究中甲状腺功能正常的参与者，年龄为 23-102 岁（N=1060）。身体表现通过综合身体表现电池（SPPB）评分进行评估。血浆 TSH、FT3 和 FT4 水平是预测因子，而 SPPB 评分是结果。
在单变量分析中，TSH、FT4 和 FT3 与年轻人的 SPPB 评分无显著相关性，而在老年参与者中，SPBB 评分与 FT3 呈正相关（P<0.001），与 TSH（P<0.02）和 FT4（P<0.001）呈负相关。在校正了多个混杂因素后，FT3 与 SPPB 仍显著相关（β±SE，0.35±0.17，P=0.04），而 FT4 和 TSH 则不相关。当同时在完全调整模型中考虑所有三种激素 FT3、FT4 和 TSH 时，结果没有改变（FT3 的β±SE，0.37±0.18，P=0.04）。
本研究结果表明，在甲状腺功能正常的老年个体中，SPPB 评分与循环 FT3 呈正相关，而与 FT4 或 TSH 无关。
在甲状腺功能正常的老年成年人中，循环 FT3 可能在甲状腺对身体功能的影响中发挥重要作用。
