Li Xiaosong, Duan Hongliang, Liu Shuang, Li Hanyang, Zhang Hong
Department of Thyroid Surgery, The Second Hospital of Jilin University, Changchun, Jilin, China.
Front Endocrinol (Lausanne). 2024 Nov 21;15:1487614. doi: 10.3389/fendo.2024.1487614. eCollection 2024.
Thyroid hormones are essential for cognitive function and can impact cognitive performance even in euthyroid individuals. This study investigates how thyroid hormones influence cognitive performance in the elderly and whether body composition biomarkers moderate this relationship. The aim is to determine if lifestyle interventions should prioritize weight loss, overall body fat reduction, or abdominal fat loss.
We analyzed data from the NHANES 2011-2012 dataset, focusing on thyroid hormone levels, cognitive performance, and body composition metrics in euthyroid individuals aged 60 to 80 years. A total of 573 participants were included in the analysis. Pearson correlation analyses were conducted to evaluate the associations between thyroid hormone indicators and cognitive performance metrics. Ordinal logistic regression and linear regression analyses were used to determine the predictive capacity of thyroid hormones on cognitive functions, adjusting for potential confounders such as age, gender, and education level. Statistical analyses were performed using R Studio and Stata, utilizing Pearson correlation, ordinal logistic regression, and linear regression methods.
Significant correlations were observed between short-term memory and TT3 ( 0.111, 0.018), TSHI ( -0.121, 0.010), and TFQI ( -0.107, 0.023); delayed memory and FT3 ( 0.143, 0.003), TT3 ( 0.146, 0.002), and TSHI ( -0.125, 0.009); and executive function with FT4 ( -0.141, 0.003) and the FT3/FT4 ratio ( 0.137, 0.004). Although thyroid indicators did not independently predict short-term memory (OR = 0.006, 0.116), they were statistically significant for delayed memory with FT3 (OR = 0.642, 0.017) and TT3 (OR = 0.010, 0.015). Linear regression analysis indicated that FT4 (t = -2.99, 0.003) and the FT3/FT4 ratio (t = 2.91, 0.004) were significant predictors of executive function. Hierarchical regression analyses revealed that BMI and waist circumference (WWI) significantly moderated the relationship between thyroid function and short-term memory (BMI: z = 2.44, 0.015; WWI: z = -2.19, 0.029). BMI also moderated the models for delayed memory (z = 2.11, 0.035), while RFM and C-index did not exhibit significant moderating effects. No moderators were identified in the relationship between executive function and thyroid hormones.
This study underscores the significant influence of higher BMI and waist circumference on the relationship between thyroid function and memory performance. In contrast, body composition indicators such as RFM and C-index do not appear to significantly affect cognitive function related to thyroid levels, highlighting the importance of fat distribution in cognitive health assessments.
甲状腺激素对认知功能至关重要，即使在甲状腺功能正常的个体中也会影响认知表现。本研究调查甲状腺激素如何影响老年人的认知表现，以及身体成分生物标志物是否会调节这种关系。目的是确定生活方式干预是否应优先考虑体重减轻、总体脂肪减少或腹部脂肪减少。
我们分析了2011 - 2012年美国国家健康与营养检查调查（NHANES）数据集的数据，重点关注60至80岁甲状腺功能正常个体的甲状腺激素水平、认知表现和身体成分指标。共有573名参与者纳入分析。进行Pearson相关性分析以评估甲状腺激素指标与认知表现指标之间的关联。使用有序逻辑回归和线性回归分析来确定甲状腺激素对认知功能的预测能力，并对年龄、性别和教育水平等潜在混杂因素进行校正。使用R Studio和Stata进行统计分析，采用Pearson相关性、有序逻辑回归和线性回归方法。
观察到短期记忆与总三碘甲状腺原氨酸（TT3）（0.111，0.018）、促甲状腺激素指数（TSHI）（-0.121，0.010）和甲状腺功能质量指数（TFQI）（-0.107，0.023）之间存在显著相关性；延迟记忆与游离三碘甲状腺原氨酸（FT3）（0.143，0.003）、TT3（0.146，0.002）和TSHI（-0.125，0.009）之间存在显著相关性；执行功能与游离甲状腺素（FT4）（-0.141，0.003）和FT3/FT4比值（0.137，0.004）之间存在显著相关性。虽然甲状腺指标不能独立预测短期记忆（比值比[OR]=0.006，0.116），但它们对FT3（OR = 0.642，0.017）和TT3（OR = 0.010，0.015）的延迟记忆具有统计学意义。线性回归分析表明，FT4（t = -2.99，0.003）和FT3/FT4比值（t = 2.91，0.004）是执行功能的显著预测因子。分层回归分析显示，体重指数（BMI）和腰围（腰围指数[WWI]）显著调节了甲状腺功能与短期记忆之间的关系（BMI：z = 2.44，0.015；WWI：z = -2.19，0.029）。BMI也调节了延迟记忆模型（z = 2.11，0.035），而相对脂肪质量（RFM）和C指数未表现出显著的调节作用。在执行功能与甲状腺激素之间的关系中未发现调节因子。
本研究强调了较高的BMI和腰围对甲状腺功能与记忆表现之间关系的显著影响。相比之下，RFM和C指数等身体成分指标似乎对与甲状腺水平相关的认知功能没有显著影响，突出了脂肪分布在认知健康评估中的重要性。
