Chinese General Practice ›› 2026, Vol. 29 ›› Issue (30): 4406-4414.DOI: 10.12114/j.issn.1007-9572.2025.0194

• Article • Previous Articles     Next Articles

The Association between the Weight-adjusted Waist Index and Thyroid Function and Autoimmunity: Insights from NHANES Data

  

  1. 1. Department of Endocrinology, Peking University First Hospital, Beijing 100034, China
    2. Statistics Division, Peking University First Hospital, Beijing 100034, China
  • Received:2025-04-10 Revised:2025-10-28 Published:2026-10-20 Online:2026-09-02
  • Contact: GAO Ying

体质量调整腰围指数与甲状腺功能和自身免疫的关系:基于NHANES数据

  

  1. 1.100034 北京市,北京大学第一医院内分泌科
    2.100034 北京市,北京大学第一医院统计室
  • 通讯作者: 高莹
  • 作者简介:

    作者贡献:

    王帅航提出研究思路,设计研究方案,数据收集、清洗,论文起草;曹业迪负责统计学分析、绘制图表、论文起草和修订;陈飞负责论文修订;朱赛楠负责统计学指导;高莹负责最终版本修订,对论文负责。

  • 基金资助:
    北京市自然科学基金昌平前沿项目(L244072)

Abstract:

Background

The relationship between obesity, thyroid function, and thyroid autoimmunity remains unclear. The weight-adjusted waist index (WWI), a novel metric for assessing obesity, enables a more accurate distinction between adipose tissue, muscle mass, and bone mass, and may serve as a superior indicator for elucidating the associations of obesity with thyroid dysfunction and autoimmunity.

Objective

This study aimed to investigate the associations of WWI with thyroid function and thyroid autoantibodies.

Methods

A total of 8 667 eligible participants were included from four cycles of the National Health and Nutrition Examination Survey (NHANES; 2001-2002, 2007-2008, 2009-2010, and 2011-2012), with complete data on WWI, thyroid function, and thyroid autoantibodies. Multivariable linear regression was applied to assess the associations of WWI with thyroid function and thyroid autoantibodies. Subgroup analyses and two-piecewise linear regression models were further conducted, and mediation analyses were performed using C-reactive protein (CRP).

Results

Multivariable linear regression showed that WWI was positively associated with free triiodothyronine (fT3), total triiodothyronine (T3), total thyroxine (T4), and thyroid peroxidase antibody (TPOAb) levels (fT3: β=0.03, 95%CI=0.01-0.04; T3: β=4.52, 95%CI=3.66-5.39; T4: β=0.20, 95%CI=0.14-0.26; TPOAb: β=3.14, 95%CI=0.25-6.04). Subgroup analyses indicated stronger associations between WWI and T3 in younger individuals (β=6.03, 95%CI=4.06-8.01), those with higher physical activity (β=5.95, 95%CI=3.78-8.13), without hypertension (β=5.46, 95%CI=4.34-6.57), and without diabetes (β=4.57, 95%CI=3.66-5.48). Higher educational attainment strengthened the association between WWI and T4 (β=0.15, 95%CI=0.07-0.23), and among individuals with higher education and no smoking history, WWI was more strongly associated with TPOAb (β=4.70, 95%CI=0.25-9.14). Saturation and threshold effects of WWI were observed for T3 and T4, with inflection points at 11.300 and 12.362, respectively. Mediation analysis suggested that CRP partially mediated the associations of WWI with T4 and fT3.

Conclusion

This study showed that the WWI was positively associated with fT3, T3, T4, and TPOAb levels. Nonlinear associations were also observed between WWI and T3 and T4 levels, with inflection points at 11.3 and 12.362, respectively. These findings suggest that WWI may be associated with thyroid function and thyroid autoimmunity; however, prospective studies are warranted to further clarify the causal relationships.

Key words: Weight-adjusted waist index, Thyroid function, Thyroid peroxidase antibody, Hashimoto's thyroiditis, Cross-sectional study

摘要:

背景

肥胖、甲状腺功能和甲状腺自身免疫之间的关系尚不明确。体质量调整腰围指数(WWI)作为评估肥胖的新指标,能够更准确地区分脂肪组织、肌肉和骨骼质量,可能成为揭示肥胖与甲状腺功能异常及自身免疫关联的更优指标。

目的

本研究旨在探讨WWI与甲状腺功能以及甲状腺自身抗体之间的关联。

方法

纳入来自国家健康与营养检查调查(NHANES)4个周期(2001—2002年、2007—2008年、2009—2010年和2011—2012年)的8 667名合格参与者,获取WWI、甲状腺功能和自身抗体的完整数据。应用多元线性回归分析探讨WWI与甲状腺功能和甲状腺自身抗体之间的关联,进一步进行亚组分析和两段式线性回归分析,并用C反应蛋白(CRP)进行中介分析。

结果

多元线性回归分析显示,WWI与游离三碘甲状腺原氨酸(fT3)、总三碘甲状腺原氨酸(T3)、总甲状腺素(T4)和甲状腺过氧化物酶抗体(TPOAb)水平呈正相关(fT3β=0.03,95%CI=0.01~0.04;T3β=4.52,95%CI=3.66~5.39;T4β=0.20,95%CI=0.14~0.26;TPOAb:β=3.14,95%CI=0.25~6.04)。亚组分析显示,在年轻人、高体力活动、无高血压或糖尿病的人群中,T3水平与WWI之间相关性更高(年轻人:β=6.03,95%CI=4.06~8.01;高体力活动:β=5.95,95%CI=3.78~8.13;无高血压:β=5.46,95%CI=4.34~6.57;无糖尿病病史:β=4.57,95%CI=3.66~5.48)。较高的受教育程度人群中WWI与T4水平之间相关性更强(β=0.15,95%CI=0.07~0.23),并且在具有较高受教育程度且无吸烟史的人群中,TPOAb水平与WWI之间的关联更强(β=4.70,95%CI=0.25~9.14)。WWI与T3、T4水平之间存在饱和效应和阈值效应,拐点分别为11.300和12.362。CRP对WWI和T4、fT3之间具有中介效应。

结论

WWI与fT3、T3、T4及TPOAb水平均呈正相关,且与T3、T4之间存在非线性关联,拐点分别为11.3和12.362。提示WWI可能与甲状腺功能及甲状腺自身免疫状态相关,但其因果关系仍需前瞻性研究进一步验证。

关键词: 体质量调整腰围指数, 甲状腺功能, 甲状腺过氧化物酶抗体, 桥本甲状腺炎, 横断面研究