Center for Clinical and Epidemiological Research, Hospital Universitário, University of São Paulo, São Paulo, Brazil.
Division of Geriatrics, University of São Paulo Medical School, São Paulo, Brazil.
J Am Geriatr Soc. 2020 Jul;68(7):1545-1553. doi: 10.1111/jgs.16416. Epub 2020 Mar 13.
We aimed to investigate the association of subclinical thyroid disease and thyroid hormone levels with sarcopenia and its defining components in community-dwelling middle-aged and older adults without overt thyroid dysfunction.
Cross-sectional study.
Active and retired employees from public institutions located in six Brazilian cities.
A total of 6974 participants from the ELSA-Brasil study's second wave, aged 50 years and older, without overt thyroid dysfunction and with complete data for exposure, outcome, and covariates.
Serum levels of thyrotropin (TSH), free thyroxine, and free triiodothyronine (FT3) were measured and divided in quintiles for the analyses. Participants were classified with euthyroidism, subclinical hypothyroidism, and subclinical hyperthyroidism. Muscle mass was assessed by bioelectrical impedance analysis and muscle strength by handgrip strength. Sarcopenia was defined according to the Foundation for the National Institutes of Health criteria. Possible confounders included sociodemographic characteristics, clinical conditions, and lifestyle. Analyses were performed separately for middle-aged and older adults (≥65 y).
The frequencies of sarcopenia, low muscle mass, low muscle strength, subclinical hypothyroidism, and subclinical hyperthyroidism were 1.5%, 20.8%, 3.8%, 9.1%, and .9%, respectively. Subclinical thyroid dysfunction was not associated with sarcopenia and its defining components. Among older adults, TSH had a U-shaped association with sarcopenia and low muscle strength. The odds ratios (ORs) (95% confidence intervals [CIs]) for the associations of the first, second, fourth, and fifth quintile with sarcopenia, respectively, were 5.18 (1.47-18.28), 6.28 (1.82-21.73), 4.12 (1.15-14.76), and 4.81 (1.35-17.10), and with low muscle strength was (OR (95% CI) for the first, second, and fifth quintiles, respectively: 1.43 (1.16-5.07), 2.07 (1.24-4.70), and 2.18 (1.03-4.60). Additionally, FT3 had a negative association with muscle mass in both age strata.
Subtle thyroid hormone alterations are associated with sarcopenia or its defining components in middle-aged and older adults without overt thyroid dysfunction. J Am Geriatr Soc 68:1545-1553, 2020.
本研究旨在调查亚临床甲状腺疾病和甲状腺激素水平与社区中年和老年人群中无显性甲状腺功能障碍的肌少症及其定义成分之间的关系。
横断面研究。
来自巴西六个城市的公共机构的在职和退休员工。
共纳入 6974 名来自 ELSA-Brasil 研究第二波、年龄在 50 岁及以上、无显性甲状腺功能障碍且暴露、结局和协变量数据完整的参与者。
测量促甲状腺激素（TSH）、游离甲状腺素和游离三碘甲状腺原氨酸（FT3）的血清水平，并将其分为五分位数进行分析。参与者被分为甲状腺功能正常、亚临床甲状腺功能减退和亚临床甲状腺功能亢进。通过生物电阻抗分析评估肌肉质量，通过握力评估肌肉力量。肌少症根据美国国立卫生研究院标准定义。可能的混杂因素包括社会人口统计学特征、临床状况和生活方式。分别对中年和老年人群（≥65 岁）进行分析。
肌少症、低肌肉量、低肌肉力量、亚临床甲状腺功能减退和亚临床甲状腺功能亢进的发生率分别为 1.5%、20.8%、3.8%、9.1%和 0.9%。亚临床甲状腺功能障碍与肌少症及其定义成分无关。在老年人群中，TSH 与肌少症和低肌肉力量呈 U 型关联。与肌少症相关的第一、二、四、五分位数的比值比（OR）（95%置信区间[CI]）分别为 5.18（1.47-18.28）、6.28（1.82-21.73）、4.12（1.15-14.76）和 4.81（1.35-17.10），与低肌肉力量相关的第一、二、五分位数的 OR（95%CI）分别为 1.43（1.16-5.07）、2.07（1.24-4.70）和 2.18（1.03-4.60）。此外，FT3 在两个年龄组中均与肌肉质量呈负相关。
在无显性甲状腺功能障碍的中年和老年人群中，轻微的甲状腺激素变化与肌少症或其定义成分有关。
美国老年医学会 68:1545-1553，2020 年。
