School of Medicine and Pharmacology, University of Western Australia, Perth, Western Australia, Australia.
Eur J Endocrinol. 2013 Sep 12;169(4):401-8. doi: 10.1530/EJE-13-0306. Print 2013 Oct.
Thyroid dysfunction predicts poorer health outcomes, but the relationship between thyroid hormone levels within the reference range and mortality in older adults remains unclear. In this study, we examined the associations between the concentrations of free thyroxine (FT4) and TSH and all-cause mortality in older men without thyroid disease.
We performed a longitudinal study in community-dwelling men aged 70-89 years. Men with thyroid disease or taking thyroid-related medications were excluded. Baseline FT4 and TSH levels were assayed. Incident deaths were ascertained using data linkage.
There were 3885 men without thyroid disease followed for (means.d.) 6.41.5 years, during which time 837 had died (21.5%). men who had died had higher baseline ft4 levels (16.22.3 vs 15.82.1 pmol/l, p0.001), but comparable tsh levels (2.41.5 vs 2.31.5 miu/l, P=0.250). After accounting for age, smoking, physical factors and medical comorbidities, higher circulating ft4 levels predicted all-cause mortality (quartile Q4 vs quartiles Q1Q3: FT4 levels ≥ 17.32 vs <17.32 pmol/l: adjusted hazard ratio (HR)=1.19, 95% CI=1.02-1.39, P=0.025). TSH levels did not predict mortality. After excluding men with subclinical hyperthyroidism or hypothyroidism, there were 3442 men and 737 who had died (21.4%). In these men, higher FT4 levels remained independently associated with all-cause mortality (quartile Q4 vs quartiles Q1-Q3: adjusted HR=1.19, 95% CI=1.02-1.41, P=0.032).
Higher FT4 levels are associated with all-cause mortality in euthyroid older men, independently of conventional risk factors and medical comorbidities. Additional research is needed to determine whether or not this relationship is causal and to clarify the utility of thyroid function testing to stratify mortality risk in ageing men.
甲状腺功能障碍可预测较差的健康结果，但甲状腺激素水平在参考范围内与老年人死亡率之间的关系仍不清楚。在这项研究中，我们检查了游离甲状腺素（FT4）和 TSH 浓度与无甲状腺疾病的老年男性全因死亡率之间的关系。
我们对 70-89 岁的社区居住男性进行了一项纵向研究。排除有甲状腺疾病或服用甲状腺相关药物的男性。检测基线 FT4 和 TSH 水平。使用数据链接确定新发死亡。
共有 3885 名无甲状腺疾病的男性随访（平均值±标准差）6.4±1.5 年，期间 837 人死亡（21.5%）。死亡的男性有更高的基础 FT4 水平（16.2±2.3 与 15.8±2.1 pmol/L，p<0.001），但 TSH 水平相当（2.4±1.5 与 2.3±1.5 mIU/L，P=0.250）。在考虑年龄、吸烟、身体因素和合并症后，较高的循环 FT4 水平预测全因死亡率（四分位 Q4 与四分位 Q1-Q3：FT4 水平≥17.32 与<17.32 pmol/L：调整后的危险比（HR）=1.19，95%CI=1.02-1.39，P=0.025）。TSH 水平不能预测死亡率。排除亚临床甲状腺功能亢进或甲状腺功能减退的男性后，有 3442 名男性和 737 名死亡（21.4%）。在这些男性中，较高的 FT4 水平仍然与全因死亡率独立相关（四分位 Q4 与四分位 Q1-Q3：调整后的 HR=1.19，95%CI=1.02-1.41，P=0.032）。
在甲状腺功能正常的老年男性中，较高的 FT4 水平与全因死亡率相关，独立于传统的危险因素和合并症。需要进一步研究以确定这种关系是否具有因果关系，并阐明甲状腺功能测试在评估老年男性死亡率风险分层中的效用。
