Table_1_Sex Differences in the Associations of Obesity With Hypothyroidism and Thyroid Autoimmunity Among Chinese Adults.pdf

There is an intensive link between obesity and thyroid dysfunction, but this relationship in Asians is still unclear. This study was conducted to define the impact of obesity on risk of hypothyroidism and thyroid autoimmunity among Chinese adults. A population-based, cross-sectional study was carried out, which enrolled a total of 2,808 Chinese adults. To assess the associations of obesity with hypothyroidism and thyroid autoimmunity, odds ratio (ORs) with 95% confidence intervals (95%CIs) were calculated through logistic regression model, and the correlations of body mass index (BMI) with TPOAb and TGAb were also analyzed. Obese females had higher risk of hypothyroidism (22.7 vs. 15.0%; OR = 1.66, 95%CI 1.10–2.53; P = 0.02) and higher risk of subclinical hypothyroidism (22.1 vs. 13.4%; OR = 1.83, 95%CI 1.20–2.80; P = 0.005) than non-obese females. Multivariate logistic regression analysis found significant associations of obesity with hypothyroidism (Adjusted OR = 1.54, 95%CI 1.00–2.38; P = 0.05) and subclinical hypothyroidism (Adjusted OR = 1.69, 95%CI 1.09–2.63; P = 0.02) in females after adjustment for confounding factors. No association between obesity and hypothyroidism was observed in male participants. Spearman's correlation analysis suggested BMI was significantly and positively correlated with TPOAb (Spearman's r = 0.062, P = 0.022) in men but not in women. Linear regression analysis suggested an obviously positive correlation of BMI with TPOAb in men (β = 0.018, P = 0.015) and an obviously negative correlation of BMI with TGAb in women (β = −0.025, P = 0.012), respectively. The study suggests sex differences in the associations of obesity with hypothyroidism and thyroid autoimmunity among Chinese adults. Further studies are needed to better understand the exact mechanism of sex difference in the obesity-thyroid relationship.

肥胖与甲状腺功能异常之间存在密切关联，但该关联在亚洲人群中仍尚不明确。本研究旨在明确肥胖对中国成人甲状腺功能减退症（hypothyroidism）及甲状腺自身免疫风险的影响。本研究采用基于人群的横断面研究设计，共纳入2808名中国成人。为评估肥胖与甲状腺功能减退症及甲状腺自身免疫的关联，本研究通过逻辑回归模型（logistic regression model）计算比值比（odds ratio，OR）及95%置信区间（95% confidence intervals，95%CI），同时分析体重指数（body mass index，BMI）与甲状腺过氧化物酶抗体（thyroid peroxidase antibody，TPOAb）、甲状腺球蛋白抗体（thyroglobulin antibody，TGAb）的相关性。相较于非肥胖女性，肥胖女性的甲状腺功能减退症患病风险更高（22.7% vs. 15.0%；OR=1.66，95%CI 1.10–2.53；P=0.02），亚临床甲状腺功能减退症（subclinical hypothyroidism）患病风险亦更高（22.1% vs. 13.4%；OR=1.83，95%CI 1.20–2.80；P=0.005）。多因素逻辑回归分析（multivariate logistic regression analysis）显示，在校正混杂因素（confounding factors）后，女性群体中肥胖与甲状腺功能减退症（校正后OR=1.54，95%CI 1.00–2.38；P=0.05）及亚临床甲状腺功能减退症（校正后OR=1.69，95%CI 1.09–2.63；P=0.02）均存在显著关联。在男性参与者中未观察到肥胖与甲状腺功能减退症的关联。斯皮尔曼相关分析（Spearman's correlation analysis）显示，仅在男性群体中，BMI与TPOAb呈显著正相关（斯皮尔曼相关系数r=0.062，P=0.022），女性群体中未发现此类关联。线性回归分析（linear regression analysis）则表明，男性群体中BMI与TPOAb呈显著正相关（β=0.018，P=0.015），而女性群体中BMI与TGAb呈显著负相关（β=−0.025，P=0.012）。本研究提示，中国成人中肥胖与甲状腺功能减退症及甲状腺自身免疫的关联存在性别差异。未来仍需开展进一步研究，以更好地阐明肥胖-甲状腺关联中性别差异的确切机制。