Department of Clinical and Molecular Endocrinology and Oncology, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy.
Eur J Endocrinol. 2010 Mar;162(3):587-9. doi: 10.1530/EJE-09-1095. Epub 2010 Jan 11.
The association of endogenous subclinical hyperthyroidism (SHyper) with cardiovascular mortality is controversial. This may reflect the different causes of endogenous SHyper in the population studied due to differences in iodine intake, and different selection criteria, e.g. sex, age, and race, the cutoff for serum TSH level, the duration of follow-up, and the presence of co-morbidities. A small sample size of SHyper patients could have caused a low statistical power in some of these studies. In other studies, the results were not adjusted for relevant confounders. Importantly, various meta-analyses have also given conflicting results. This issue of the European Journal of Endocrinology contains two articles that address the association between endogenous SHyper and cardiovascular and total mortality: one study was conducted in a north-eastern German population and the other in a Japanese-Brazilian population. After adjusting for relevant confounders, there was no association between decreased serum TSH levels and all-cause and cardiovascular mortality in the Pomerania study; on the contrary, all-cause mortality and cardiovascular mortality were significantly higher for individuals with SHyper in the Japanese-Brazilian population. Interestingly, both studies had similar characteristics in terms of selection criteria and duration of follow-up. It remains controversial whether or not to treat middle-aged patients with low serum TSH levels. Large prospective randomized controlled double-blind studies of young and middle-aged patients with SHyper and without underlying cardiac disease are required to assess the potential benefits of treating endogenous SHyper in these age groups.
内源性亚临床甲状腺功能亢进症（SHyper）与心血管死亡率之间的关联存在争议。这可能反映了研究人群中内源性 SHyper 的不同原因，由于碘摄入量、性别、年龄和种族、血清 TSH 水平的临界值、随访时间以及合并症的不同，导致了这些原因的不同。在一些研究中，SHyper 患者的样本量较小，可能导致统计学效力较低。在其他研究中，结果没有调整相关混杂因素。重要的是，各种荟萃分析也给出了相互矛盾的结果。本期《欧洲内分泌学杂志》包含两篇文章，探讨了内源性 SHyper 与心血管和全因死亡率之间的关系：一项研究在德国东北部人口中进行，另一项在日本-巴西人口中进行。在调整了相关混杂因素后，在波美拉尼亚研究中，血清 TSH 水平降低与全因和心血管死亡率之间没有关联；相反，在日本-巴西人群中，SHyper 个体的全因死亡率和心血管死亡率显著更高。有趣的是，这两项研究在选择标准和随访时间方面具有相似的特征。对于中年患者血清 TSH 水平降低是否需要治疗仍存在争议。需要对无潜在心脏疾病的年轻和中年 SHyper 患者进行大型前瞻性随机对照双盲研究，以评估在这些年龄组中治疗内源性 SHyper 的潜在益处。
