1 Department of Endocrinology and Metabolism, Shandong Provincial Hospital affiliated to Shandong University , Jinan, China .
Thyroid. 2015 May;25(5):485-93. doi: 10.1089/thy.2014.0219. Epub 2015 Apr 9.
Dyslipidemia is an important global health problem, particularly in the elderly population. Traditionally, the high prevalence of dyslipidemia in elderly people is considered a "natural condition." Notably, subclinical hypothyroidism (SCH) is one of the most important risk factors for dyslipidemia. Few studies have assessed whether SCH plays a role in the increase in age-related dyslipidemia. This study aimed to explore the association between SCH and lipid profiles in different age groups.
This was a large-scale, population-based, case-control study. The population was derived from the REACTION study conducted across China. A total of 17,046 individuals (8827 cases and 8219 controls) aged 40 years or older were enrolled in the final analyses. The relationships between SCH and serum lipid parameters in each age group were evaluated after adjustment for thyroid hormones and common confounding factors.
In the entire population, thyrotropin (TSH), the key indicator of SCH, was positively associated with cholesterol parameters (total cholesterol [TC] and low-density lipoprotein cholesterol [LDL-C]) through the sixth decade of life. After adjusting for common confounding factors and thyroid hormones, each 1 mIU/L increase in TSH was estimated to elevate the TC level by 0.0147 mmol/L and 0.0551 mmol/L, respectively, in individuals aged 40-49 years and 60-69 years. Similarly, with each 1 mIU/L increase in TSH, the LDL-C level tended to show gradually greater increases as age increased. In moderately old subjects (60-69 years), mild (TSH≤10 mIU/L) and significant (TSH>10 mIU/L) SCH increased the concentration of TC approximately 1.03- and 1.36-fold, and the concentration of LDL-C approximately 1.19- and 1.65-fold, respectively, when compared with younger subjects.
TSH exhibited a stronger effect on the TC and LDL-C level in moderately old subjects than in younger subjects. SCH might augment and worsen the effects of aging on serum lipid profiles.
血脂异常是一个重要的全球健康问题，尤其是在老年人群中。传统上，老年人血脂异常的高发被认为是一种“自然状态”。值得注意的是，亚临床甲状腺功能减退症（SCH）是血脂异常的最重要危险因素之一。很少有研究评估 SCH 是否在与年龄相关的血脂异常增加中起作用。本研究旨在探讨 SCH 与不同年龄组血脂谱之间的关系。
这是一项大规模的、基于人群的病例对照研究。该人群来源于中国进行的 REACTION 研究。最终分析共纳入 17046 名年龄在 40 岁及以上的个体（8827 例病例和 8219 例对照）。调整甲状腺激素和常见混杂因素后，评估了 SCH 与各年龄组血清脂质参数之间的关系。
在整个人群中，促甲状腺激素（TSH），SCH 的关键指标，在生命的第六个十年通过与胆固醇参数（总胆固醇[TC]和低密度脂蛋白胆固醇[LDL-C]）呈正相关。在调整常见混杂因素和甲状腺激素后，40-49 岁和 60-69 岁个体中，TSH 每增加 1mIU/L，TC 水平分别升高 0.0147mmol/L 和 0.0551mmol/L。同样，随着 TSH 每增加 1mIU/L，LDL-C 水平随着年龄的增长呈逐渐升高趋势。在中老年人（60-69 岁）中，轻度（TSH≤10mIU/L）和显著（TSH>10mIU/L）SCH 使 TC 浓度分别增加约 1.03 倍和 1.36 倍，LDL-C 浓度分别增加约 1.19 倍和 1.65 倍，与年轻受试者相比。
TSH 对中老年人 TC 和 LDL-C 水平的影响强于年轻人。SCH 可能会增强和加重衰老对血清脂质谱的影响。
