左甲状腺素钠替代治疗改善甲状腺机能减退症患者左心室心肌弥漫性病变的研究

高霞，刘敏，杨宁，杨新春，王广



左甲状腺素钠替代治疗改善甲状腺机能减退症患者左心室心肌弥漫性病变的研究

高霞，刘敏，杨宁，杨新春，王广

摘要

目的：采用心脏磁共振T1 mapping技术无创性定量评估甲状腺机能减退症（甲减）患者左心室心肌的弥漫性病变，以及左甲状腺素钠替代治疗对左心室心肌病变和心功能的影响。

方法：纳入初诊的临床甲减患者（甲减组）20例，及健康志愿者（对照组）17例。采用心脏磁共振T1 mapping技术评价左甲状腺素钠治疗前后甲减患者左心室心肌T1值及左心功能的改变，并分别将T1值与甲状腺功能和左心功能指标进行相关性分析。

结果：（1）与对照组相比，甲减组患者左心室心肌T1值明显升高（P＜0.01），并且心脏指数和左心室高峰充盈率显著降低（P＜0.05）；（2）甲减组患者左心室心肌T1值与血清游离三碘甲腺原氨酸（FT3）（r=-0.52, P=0.0006）和左心室高峰充盈率（r=-0.43, P=0.0085）呈负相关；（3）给予甲减组患者左甲状腺素钠替代治疗恢复正常甲状腺功能后，与治疗前相比，左心室心肌T1值明显降低，并且心脏指数和左心室高峰充盈率较治疗前显著改善。

结论：甲减可以导致左心室心肌弥漫性病变以及左心功能异常，这种心肌弥漫性病变可以被心脏磁共振T1 mapping技术评估。而左甲状腺素钠替代治疗可以改善甲减患者的左心室心肌弥漫性病变，继而改善左心功能。

关键词 甲状腺疾病；T1 mapping；心肌疾病；甲状腺素

Objective: To study the effect of levothyroxine replacement therapy on improving diffused left ventricular myocardial lesions and cardiac function in patients with hypothyroidism.

Methods: Our research included 2 groups: Hypothyroidism group, n=20 newly diagnosed patients and Control group, n=17 normal healthy subjects. Diffused left ventricular myocardial lesions were quantitatively evaluated by non-invasive cardiac MRI T1 mapping technique. Left ventricular myocardial T1 value and left ventricular function before and after levothyroxine replacement therapy were compared; the relationship between T1 value and thyroid function and the relationship between T1 value and the indicators of left ventricular function were analyzed.

Results:①Compared with Control group, Hypothyroidism group had increased left ventricular myocardial T1 value, P＜0.01, while decreased cardiac index (CI) and left ventricular peak filling rate (PFR), all P＜0.05.②In patients with hypothyroidism, left ventricular myocardial T1 value was negatively related to serum FT3 level (r=-0.52, P=0.0006) and PFR (r=-0.43, P=0.0085).③Compared with pre-therapeutic condition, the patients with recovered normal thyroid function showed obviously decreased left ventricular myocardial T1 value and improved CI, PFR.

Conclusion: Levothyroxine replacement therapy may improve diffused left ventricular myocardial lesions in patients with hypothyroidism, and therefore improve the cardiac function.

Key words Thyroid diseases; T1 mapping; Cardiomyopathies; Thyroxin (Chinese Circulation Journal, 2016,31:349.)

甲状腺激素对于维持心血管稳态发挥着至关重要的作用[1]。我们课题组以往研究发现，甲状腺机能减退症（甲减）患者低密度脂蛋白胆固醇以及同型半胱氨酸水平明显升高，且增加了患者的胰岛素抵抗[2]。……