From the Department of Epidemiology (A.K.), Helmholtz Centre for Infection Research, Braunschweig, Germany; Faculty of Epidemiology & Population Health (A.K., S.L.T.), London School of Hygiene and Tropical Medicine, UK; and Department of Neurology (A.K.), University Medical Center Göttingen, Germany.
Neurology. 2014 May 6;82(18):1643-52. doi: 10.1212/WNL.0000000000000377. Epub 2014 Apr 9.
To investigate the effect of autoimmune thyroiditis (AIT) on risk of stroke and to assess whether any increased risk (1) varied by AIT duration, and (2) was independent of classic cardiovascular risk factors.
This was a large historical cohort study using data from The Health Improvement Network Database. Rates of first stroke during follow-up in thyroxine-treated patients with AIT (n = 34,907) were compared with those in matched individuals without AIT (n = 149,632) using random-effects Poisson regression models.
There was strong evidence for a slightly increased risk of stroke in patients with AIT (adjusted rate ratio = 1.10, 95% confidence interval: 1.01-1.20). The observed increase was partly independent of cardiovascular risk factors. Higher effect sizes were identified in the first year after AIT diagnosis (rate ratio = 1.33, 95% confidence interval: 1.14-1.56) but not in the long-term, consistent with a residual effect of hypothyroidism.
Our results support the hypothesis of a slightly increased risk of stroke in patients with AIT. The higher effect size found soon after AIT diagnosis suggests an increased cardiovascular risk due to thyroid-hormone deficiency rather than a cumulative effect of autoimmune pathology. Better screening and early treatment of patients with asymptomatic hypothyroid AIT could help reduce excess risk of stroke in the first year after diagnosis.
探讨自身免疫性甲状腺炎（AIT）对卒中风险的影响，并评估这种风险增加是否（1）与 AIT 持续时间有关，以及（2）是否独立于经典心血管危险因素。
这是一项使用来自健康改善网络数据库的数据进行的大型历史队列研究。采用随机效应泊松回归模型，比较甲状腺素治疗的 AIT 患者（n=34907）和匹配的无 AIT 个体（n=149632）在随访期间首次卒中的发生率。
AIT 患者卒中风险略有增加的证据较强（调整后的发病比=1.10，95%置信区间：1.01-1.20）。观察到的增加部分独立于心血管危险因素。在 AIT 诊断后的第一年观察到更高的效应大小（发病比=1.33，95%置信区间：1.14-1.56），但在长期内没有观察到，这与甲状腺功能减退的残留效应一致。
我们的结果支持 AIT 患者卒中风险略有增加的假设。在 AIT 诊断后不久发现的更高效应大小表明，由于甲状腺激素缺乏而导致心血管风险增加，而不是自身免疫病理学的累积效应。更好地筛查和早期治疗无症状性甲状腺功能减退性 AIT 患者可能有助于降低诊断后第一年的卒中风险。
