新诊断的2型糖尿病患者血管内皮功能与甲状腺激素敏感性相关性的研究

The correlation between vascular endothelial function and thyroid hormone sensitivity in newly diagnosed type 2 diabetes patients

目的探讨新诊断的2型糖尿病(type 2 diabetes mellitus,T2DM)患者血管内皮功能与甲状腺激素敏感性指数的相关性。方法选取2019年6月至2020年11月,于首都医科大学附属北京朝阳医院内分泌门诊就诊的新诊断T2DM患者100例,测定空腹血糖(fasting blood glucose,FBG)、糖化血红蛋白(glycosylated hemoglobin A1c,HbA1c)、空腹胰岛素(fasting insulin,FIns)以及游离三碘甲状腺原氨酸(free thiiodothyronine,FT3)、游离甲状腺素(free thyroxine,FT4)、促甲状腺激素(thyroid stimulating hormone,TSH)和血脂等其他代谢指标。根据FT4和TSH水平,由公式计算出甲状腺反馈分位指数(thyroid feedback quantile index,TFQI)、TSH指数(TSH index,TSHI)、促甲状腺素抵抗指数(thyrotroph thyroxine resistance index,TT4RI)作为中枢甲状腺激素敏感性指数,数值越高,代表中枢甲状腺激素敏感性越低;FT3/FT4表示外周甲状腺激素敏感性,数值越低敏感性越低。计算稳态模型评估胰岛素抵抗指数(homeostasis model assessment of insulin resistance,HOMA-IR)。同时,所有受试者测定血管内皮反应性充血指数(reactive hyperemia index,RHI)作为评价血管内皮功能的指标,并按照RHI结果分为合并内皮功能损害组(T2DM-ED组,RHI<1.67,43例)和不合并内皮功能损害组(T2DM-NED组,RHI≥1.67,57例)。结果T2DM-ED组的RHI为1.41±0.21,T2DM-NED组RHI为1.91±0.26;T2DM-ED组低密度脂蛋白胆固醇(low density lipoprotein-cholesterol,LDL-C)、FBG、HbA1c均明显高于T2DM-NED组(P<0.05);TSH、TFQI、TSHI、LnTT4RI亦高于T2DM-NED组(P<0.05);Pearson相关分析显示,RHI与LDL-C、FBG、LnHOMA-IR、HbA1c以及TSH、TFQI、TSHI、LnTT4RI均呈负相关,与FT3/FT4呈正相关。多元线性回归分析显示,HbA1c、LDL-C、TFQI、LnTT4RI、TSHI、TSH是新诊断T2DM患者RHI降低的影响因素。结论在新诊断的T2DM患者中,甲状腺激素敏感性可能参与了血管内皮功能损害的发生。

Objective To explore the association between vascular endothelial function and the sensitivity to thyroid hormones in patients newly diagnosed type 2 diabetes mellitus(T2DM).Methods A cohort of 100 patients newly diagnosed with T2DM attending the endocrinology outpatient clinic of Beijing Chaoyang Hospital,Capital Medical University from June 2019 to November 2020 was enrolled.Key parameters measured encompassed fasting blood glucose(FBG),glycosylated hemoglobin A1c(HbA1c),free triiodothyronine(FT3),free thyroxine(FT4),thyroid-stimulating hormone(TSH),and lipid profiles among other metabolic indices.Indices of central thyroid hormone sensitivity,such as the thyroid feedback quantile index(TFQI),TSH index(TSHI),and the thyrotroph thyroxine resistance index(TT4RI),were computed based on FT4 and TSH levels,with higher values indicating diminished central thyroid hormone sensitivity.Conversely,the FT3/FT4 ratio was assessed as a marker of peripheral thyroid hormone sensitivity,with lower ratios suggesting reduced sensitivity.The homeostasis model assessment of insulin resistance(HOMA-IR)was caculated.The reactive hyperemia index(RHI)was measured across all participants to evaluate vascular endothelial function.Then,all subjects were divided into two groups based on RHI results:T2DM-ED group(RHI<1.67,43 cases)those with combined vascular endothelial dysfunction and and T2DM-NED group(RHI≥1.67,57 cases)those without vascular endothelial dysfunction.Results The RHI level of the T2DM-ED group was 1.41±0.21,while the RHI level of the T2DM-NED group is 1.91±0.26.In comparison to the T2DM-NED group,individuals within the T2DM-ED group manifested markedly higher levels of low density lipoprotein-cholesterol(LDL-C),FBG and HbA1c(P<0.05).Furthermore,TSH,TFQI,TSHI and LnTT4RI were notably higher in the T2DM-ED group(P<0.05).Pearson correlation analysis revealed a negative correlation between RHI and LDL-C,FBG,LnHOMA-IR,HbA1c,TSH,TFQI,TSHI,and LnTT4RI,and a positive correlation with the FT3/FT4 ratio.Multivariate linear regression analysis identified HbA1c,LDL-C,TFQI,LnTT4RI,TSHI and TSH as factors associated with the reduction of RHI in patients newly diagnosed with T2DM.Conclusion The findings suggest that vascular endothelial dysfunction in newly diagnosed T2DM patients may be intricately linked to decreased sensitivity to thyroid hormones,underscoring the potential interplay between metabolic dysregulation and thyroid hormone pathways in the pathogenesis of T2DM-related vascular complications.