Division of Endocrinology, Jewish General Hospital, Montreal, Canada.
Department of Medicine, McGill University, Montreal, Canada.
Thyroid. 2024 Oct;34(10):1214-1224. doi: 10.1089/thy.2024.0227. Epub 2024 Aug 22.
There is uncertainty as to whether treatment of subclinical hypothyroidism (SCH) is associated with cardiovascular outcomes. To determine whether levothyroxine replacement therapy decreases the risk of major adverse cardiovascular events (MACE) among individuals with SCH defined as having a thyrotropin (TSH) level between 5 and 10 mU/L. We conducted a population-based cohort study using a prevalent new-user design. The study utilized data from the United Kingdom Clinical Practice Research Datalink. We identified a base cohort of individuals aged ≥18 years with incident SCH defined as having at least two TSH levels between 5 and 10 mU/L within one year between 1998 and 2018. We matched 76,946 levothyroxine treated to 76,946 untreated individuals based on age, sex, calendar time, duration of SCH, and time-conditional propensity score. We compared individuals with SCH treated with levothyroxine with individuals with no treatment. Levothyroxine treatment versus no treatment. The primary outcome, MACE, was defined as a composite of nonfatal myocardial infarction, nonfatal ischemic stroke, and cardiovascular-related mortality. The mean age of the study cohort was 62.8 years, and 76.5% were women. During a median follow-up time of 1.6 years (interquartile range: 0.5-4.2), the incidence rate for MACE among individuals treated with levothyroxine was 12.8 per 1000 person-years; confidence interval (CI): 12.2-13.3 and 13.9 per 1000 person-years; CI: 13.4-14.3 among nontreated individuals. Levothyroxine treatment was associated with a small decreased risk of MACE (hazard ratio: 0.88; CI: 0.83-0.93). Levothyroxine treatment of SCH was associated with a small decreased risk of MACE. However, given the observational nature of the study, residual confounding should be considered in the interpretation of this finding.
对于亚临床甲状腺功能减退症（SCH）的治疗是否与心血管结局相关存在不确定性。本研究旨在确定左甲状腺素替代疗法是否可以降低促甲状腺激素（TSH）水平在 5 至 10 mU/L 之间的 SCH 患者发生主要不良心血管事件（MACE）的风险。我们采用基于人群的队列研究设计，利用英国临床实践研究数据链接进行了这项研究。我们确定了一个基础队列，其中包含了年龄≥18 岁的至少两次 TSH 水平在 5 至 10 mU/L 之间的新发生 SCH 患者，其发病时间在 1998 年至 2018 年的一年内。我们根据年龄、性别、时间、SCH 持续时间和时间条件倾向评分匹配了 76946 例接受左甲状腺素治疗的患者和 76946 例未接受治疗的患者。我们将接受左甲状腺素治疗的 SCH 患者与未接受治疗的患者进行了比较。左甲状腺素治疗与未治疗。主要结局 MACE 定义为非致死性心肌梗死、非致死性缺血性卒中和心血管相关死亡率的复合结局。研究队列的平均年龄为 62.8 岁，76.5%为女性。在中位随访时间为 1.6 年（四分位距：0.5-4.2）期间，接受左甲状腺素治疗的患者的 MACE 发生率为每 1000 人年 12.8 例（置信区间 [CI]：12.2-13.3），未接受治疗的患者为每 1000 人年 13.9 例（CI：13.4-14.3）。左甲状腺素治疗与 MACE 风险降低相关（风险比：0.88；95%CI：0.83-0.93）。SCH 患者接受左甲状腺素治疗与 MACE 风险降低相关。然而，鉴于该研究的观察性质，在解释这一发现时应考虑残余混杂因素。
