Institute for Community Medicine, Ernst Moritz Arndt University, University of Greifswald, Walther Rathenau Strasse 48, D-17487 Greifswald, Germany.
Eur J Endocrinol. 2010 Mar;162(3):579-85. doi: 10.1530/EJE-09-0566. Epub 2009 Dec 9.
Results of cohort studies on the association between decreased serum TSH levels and mortality are conflicting. Some studies demonstrated an increased mortality risk in subjects with decreased serum TSH levels, others did not. Even meta-analyses revealed contradictory results. We undertook the present study to investigate the association between decreased serum TSH levels and mortality in the large population-based Study of Health in Pomerania (SHIP).
Data from 3651 individuals from SHIP without known thyroid disorders or thyroid treatment were analyzed. Serum TSH, free triiodothyronine, and free thyroxine levels were determined by immunochemiluminescent procedures. Decreased TSH was defined as serum TSH levels below 0.25 mIU/l. Cox regression was used to associate decreased TSH levels with mortality.
The median duration of follow-up was 8.5 years (30 126 person years). During follow-up, 299 individuals (6.9%) died corresponding to a death rate of 9.92 deaths per 1000 person years. Survival time was shorter in subjects with decreased serum TSH levels compared to euthyroid individuals. After adjustment for age and sex, however, there was no association between decreased serum TSH levels and all-cause mortality (hazard ratio: 0.95; 95% confidence interval: 0.67; 1.36). Likewise, decreased serum TSH levels were neither associated with cardiovascular nor with cancer mortality.
There is no independent association of decreased serum TSH levels with all-cause, cardiovascular, and cancer mortality in the adult northeast German population. Although our study has some strengths, we cannot finally conclude on therapeutical implications in individuals with subclinical thyroid diseases.
关于血清 TSH 水平降低与死亡率之间的关系的队列研究结果存在矛盾。一些研究表明，血清 TSH 水平降低的受试者死亡风险增加，而另一些研究则没有。即使是荟萃分析也得出了相互矛盾的结果。我们进行了本项研究，以调查在基于人群的波罗的海健康研究（SHIP）中，血清 TSH 水平降低与死亡率之间的关系。
分析了来自 SHIP 的 3651 名无已知甲状腺疾病或甲状腺治疗的个体的数据。采用免疫化学发光法测定血清 TSH、游离三碘甲状腺原氨酸和游离甲状腺素水平。血清 TSH 降低定义为血清 TSH 水平低于 0.25mIU/L。使用 Cox 回归分析将 TSH 降低与死亡率相关联。
中位随访时间为 8.5 年（30126人年）。随访期间，299 名个体（6.9%）死亡，死亡率为每 1000 人年 9.92 例。与甲状腺功能正常个体相比，血清 TSH 降低的个体的生存时间更短。然而，在调整年龄和性别后，血清 TSH 降低与全因死亡率之间没有关联（风险比：0.95；95%置信区间：0.67；1.36）。同样，血清 TSH 降低与心血管或癌症死亡率也没有关联。
在德国东北部成年人中，血清 TSH 降低与全因、心血管和癌症死亡率之间没有独立的关联。尽管我们的研究有一些优势，但我们不能最终得出关于亚临床甲状腺疾病患者治疗的结论。
