Roos Annemieke, Bakker Stephan J L, Links Thera P, Gans Rijk O B, Wolffenbuttel Bruce H R
Department of Endocrinology, University Medical Center Groningen and University of Groningen, P.O. Box 30001, 9700 RB Groningen, The Netherlands.
J Clin Endocrinol Metab. 2007 Feb;92(2):491-6. doi: 10.1210/jc.2006-1718. Epub 2006 Nov 7.
Thyroid disease and the metabolic syndrome are both associated with cardiovascular disease.
The aim of this study was to explore the hypothesis that thyroid function, in euthyroid subjects, is associated with components of the metabolic syndrome, including serum lipid concentrations and insulin resistance.
A total of 2703 adult inhabitants of a middle-sized city in The Netherlands participated in this cross-sectional study. Subjects who were not euthyroid were excluded, as were subjects taking thyroid medication, medication for diabetes, and subjects for whom medication data were not available (n = 1122). Homeostasis model assessment for insulin resistance (HOMA-IR) (mU*mmol/liter2) was calculated as fasting insulin (mU/liter) times fasting glucose (mmol/liter) divided by 22.5. The metabolic syndrome was defined according to National Cholesterol Education Program's Adult Treatment Panel III criteria.
After adjustment for age and sex, free T4 (FT4) was significantly associated with total cholesterol [standardized beta (beta) = -0.059; P = 0.014], low-density lipoprotein cholesterol (beta = -0.068; P = 0.004), high-density lipoprotein cholesterol (beta = 0.100; P < 0.001), and triglycerides (beta = -0.102; P < 0.001). Both FT4 and TSH were significantly associated with HOMA-IR (beta = -0.133; P < 0.001 and beta = 0.055; P = 0.024, respectively). Median HOMA-IR increased from 1.42 in the highest tertile of FT4 to 1.66 in the lowest tertile of FT4. FT4 was significantly related to four of five components of the metabolic syndrome (abdominal obesity, triglycerides, high-density lipoprotein cholesterol, and blood pressure), independent of insulin resistance.
We have demonstrated an association between FT4 levels within the normal reference range and lipids, in accordance with the earlier observed association between (sub)clinical hypothyroidism and hyperlipidemia. Moreover, low normal FT4 levels were significantly associated with increased insulin resistance. These findings are consistent with an increased cardiovascular risk in subjects with low normal thyroid function.
甲状腺疾病和代谢综合征均与心血管疾病相关。
本研究旨在探讨如下假说：甲状腺功能正常的受试者的甲状腺功能与代谢综合征的组成部分相关，包括血脂浓度和胰岛素抵抗。
荷兰一个中等规模城市的2703名成年居民参与了这项横断面研究。非甲状腺功能正常的受试者、正在服用甲状腺药物或糖尿病药物的受试者以及药物数据不可用的受试者（n = 1122）被排除。胰岛素抵抗的稳态模型评估（HOMA-IR）（mU*mmol/升²）的计算方法为空腹胰岛素（mU/升）乘以空腹血糖（mmol/升）再除以22.5。代谢综合征根据美国国家胆固醇教育计划成人治疗小组第三次报告的标准进行定义。
在对年龄和性别进行校正后，游离T4（FT4）与总胆固醇显著相关[标准化β（β） = -0.059；P = 0.014]、低密度脂蛋白胆固醇（β = -0.068；P = 0.004）、高密度脂蛋白胆固醇（β = 0.100；P < 0.001）和甘油三酯（β = -0.102；P < 0.001）。FT4和促甲状腺激素（TSH）均与HOMA-IR显著相关（分别为β = -0.133；P < 0.001和β = 0.055；P = 0.024）。HOMA-IR中位数从FT4最高三分位数的1.42增加到FT4最低三分位数的1.66。FT4与代谢综合征的五个组成部分中的四个（腹型肥胖、甘油三酯、高密度脂蛋白胆固醇和血压）显著相关，且独立于胰岛素抵抗。
我们已证明正常参考范围内的FT4水平与血脂之间存在关联，这与之前观察到的（亚）临床甲状腺功能减退与高脂血症之间的关联一致。此外，正常低限的FT4水平与胰岛素抵抗增加显著相关。这些发现与甲状腺功能正常低限的受试者心血管风险增加相一致。
