Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA.
PLoS One. 2013 Apr 12;8(4):e59489. doi: 10.1371/journal.pone.0059489. Print 2013.
Altered thyroid status exerts a major effect on the heart. Individuals with hypo- or hyperthyroidism showed various changes in electrocardiograms. However, little is known about how variations in thyroid hormone levels within the normal range affect electrical activities of the heart in the general population.
We conducted a cross-sectional analysis of 5,990 men and women from the Third National Health and Nutrition Examination Survey. Serum total T4 was measured by immunoassay and TSH was measured by chemiluminescent assay. We categorized T4 and TSH into 7 groups with cut-offs at the 5(th), 20(th), 40(th), 60(th), 80(th), and 95(th) percentiles of the weighted population distribution. Electrocardiographic parameters were measured from the standard 12-lead electrocardiogram. We found a positive linear association between serum total T4 level and heart rate in men, and a U-shape association between T4 and PR interval in men and women. TSH level was positively associated with QRS interval in men, while a U-shape association between TSH and QRS was observed in women. No clear graded association between thyroid hormones and corrected QT or JT was found, except that men in the highest category of T4 levels appeared to have longer corrected QT and JT, and men in the lowest category of T4 appeared to have shorter corrected QT and JT.
Variation in thyroid hormone levels in the general population, even within the normal range, was associated with various ECG changes.
甲状腺状态的改变对心脏有重大影响。甲状腺功能减退或甲状腺功能亢进的个体心电图显示出各种变化。然而，对于甲状腺激素水平在正常范围内的变化如何影响一般人群心脏的电活动，人们知之甚少。
我们对来自第三次国家健康和营养检查调查的 5990 名男性和女性进行了横断面分析。通过免疫测定测量血清总 T4，通过化学发光测定测量 TSH。我们将 T4 和 TSH 分为 7 组，以加权人群分布的第 5、20、40、60、80 和 95 百分位为切点。心电图参数是从标准的 12 导联心电图中测量出来的。我们发现血清总 T4 水平与男性的心率呈正线性关系，而 T4 与 PR 间期在男性和女性中呈 U 形关系。TSH 水平与男性的 QRS 间隔呈正相关，而 TSH 与 QRS 间隔在女性中呈 U 形关系。除了 T4 水平最高组的男性似乎具有更长的校正 QT 和 JT 外，甲状腺激素与校正 QT 或 JT 之间没有明显的分级关联，而 T4 水平最低组的男性似乎具有更短的校正 QT 和 JT。
即使在正常范围内，人群中甲状腺激素水平的变化也与各种心电图变化有关。
