Table 1_The study on serum oxidized low-density lipoprotein and homocysteine as cardiovascular risk markers in subclinical hypothyroidism patients.docx

PurposeHypothyroidism, the most prevalent endocrine disorder globally, is associated with increased cardiovascular risk. This study aims to evaluate cardiovascular risk factors—including serum oxidized low-density lipoprotein (ox-LDL), serum homocysteine (Hcy), and lipid profiles—and their correlations with thyroid-stimulating hormone (TSH) levels. Early identification of these risk predictors may reduce the incidence and mortality of cardiovascular disease in hypothyroid patients.
Patients and methodsThis cross-sectional study included 676 participants. Subjects were stratified into four groups: three corresponding to TSH quartiles within the reference range and a fourth comprising subclinical hypothyroidism (SCH) patients with TSH levels above this range. All participants underwent physical examinations and provided fasting blood samples for measurement of TSH, free thyroxine (FT4), free triiodothyronine (FT3), blood glucose, triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB), lipoprotein(a) [Lp(a)], ox-LDL, and Hcy.
ResultsAcross the four subgroups, LDL-C, ApoB, ox-LDL, and Hcy levels exhibited significant increasing trends (all p < 0.05; specific p = 0.01, p = 0.01, p < 0.01, p < 0.01, respectively), whereas HDL-C decreased significantly (p < 0.01). Specifically, compared to the T1 subgroup (TSH: 0.27-1.58 mIU/L), the SCH subgroup (TSH ≥ 4.20 mIU/L) had significantly higher levels of ox-LDL (1.78 ± 0.49 ng/mL vs. 1.05 ± 0.68 ng/mL, p < 0.01) and Hcy (9.87 (interquartile range (IQR): 8.45-11.42) μmol/L vs. 9.22 (IQR: 8.11-10.11) μmol/L, p < 0.01), and lower levels of HDL-C (1.29 ± 0.36 mmol/L vs. 1.43 ± 0.39 mmol/L, p < 0.01). After adjusting for age and sex, TSH levels demonstrated positive correlations with body mass index (BMI), triglycerides, total cholesterol, LDL-C, ApoB, ox-LDL, and Hcy (all p < 0.05), and a negative correlation with HDL-C (p = 0.01). Multiple linear regression analysis revealed that TSH levels were independently associated with elevated ox-LDL (β = 0.18, p < 0.01) and Hcy (β = 0.11, p < 0.01), and reduced HDL-C (β = −0.16, p = 0.01).
ConclusionThe observed correlations between ox-LDL, Hcy, and dyslipidemia in subclinical hypothyroidism may indicate a proatherogenic state. Elevated ox-LDL and Hcy emerge as independent factors associated with accelerated atherosclerosis in this condition.

甲状腺功能减退症（Hypothyroidism）是全球范围内最为高发的内分泌疾病，与心血管疾病风险升高密切相关。本研究旨在评估心血管危险因素——包括血清氧化低密度脂蛋白（ox-LDL）、血清同型半胱氨酸（Hcy）及血脂谱——及其与促甲状腺激素（TSH）水平的相关性。早期识别此类风险预测因子，或可降低甲状腺功能减退患者心血管疾病的发病率与死亡率。

患者与方法 本项横断面研究共纳入676名受试者。按TSH水平将受试者分为四组：三组为参考范围内的TSH四分位组，第四组为TSH超出该参考范围的亚临床甲状腺功能减退症（SCH）患者。所有受试者均接受体格检查，并采集空腹静脉血样以检测TSH、游离甲状腺素（FT4）、游离三碘甲状腺原氨酸（FT3）、血糖、甘油三酯（TG）、总胆固醇（TC）、高密度脂蛋白胆固醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）、载脂蛋白A1（ApoA1）、载脂蛋白B（ApoB）、脂蛋白(a) [Lp(a)]、ox-LDL及Hcy。

结果 四组亚组间，LDL-C、ApoB、ox-LDL及Hcy水平均呈现显著升高趋势（所有P<0.05；具体分别为P=0.01、P=0.01、P<0.01、P<0.01），而HDL-C水平则显著降低（P<0.01）。具体而言，与T1亚组（TSH：0.27~1.58 mIU/L）相比，SCH亚组（TSH≥4.20 mIU/L）的ox-LDL水平（1.78±0.49 ng/mL 相较于 1.05±0.68 ng/mL，P<0.01）与Hcy水平[9.87（四分位距IQR：8.45~11.42）μmol/L 相较于 9.22（IQR：8.11~10.11）μmol/L，P<0.01]均显著升高，HDL-C水平（1.29±0.36 mmol/L 相较于 1.43±0.39 mmol/L，P<0.01）则显著降低。校正年龄与性别因素后，TSH水平与体质量指数（BMI）、甘油三酯、总胆固醇、LDL-C、ApoB、ox-LDL及Hcy均呈正相关（所有P<0.05），与HDL-C呈负相关（P=0.01）。多重线性回归分析结果显示，TSH水平与ox-LDL升高（β=0.18，P<0.01）、Hcy升高（β=0.11，P<0.01）及HDL-C降低（β=-0.16，P=0.01）独立相关。

结论 本研究观察到的亚临床甲状腺功能减退症患者中ox-LDL、Hcy与血脂异常的相关性，或提示存在致动脉粥样硬化状态。升高的ox-LDL与Hcy可作为该疾病群体中动脉粥样硬化加速进展的独立相关因素。