Department of Clinical Medicine and Surgery (R.L., A.T., A.S., M.C., L.B., P.A., G.A.L., G.L.), Federico II University, 80131 Naples, Italy; and Unit of Cell and Molecular Biology in Cardiovascular Diseases (M.N.D.D.M., A.D.M.), Centro Cardiologico Monzino, Istituto di Ricovero e Cura a Carattere Scientifico, 20122 Milan, Italy.
J Clin Endocrinol Metab. 2015 Jul;100(7):2659-65. doi: 10.1210/jc.2015-1726. Epub 2015 May 8.
Subclinical hypothyroidism (SH) is associated with some abnormalities in primary and secondary hemostasis.
The objective of the study was to evaluate changes in primary and secondary hemostasis induced by levothyroxine (L-T4) treatment in SH patients.
This was a prospective cohort study with a 6-month follow-up.
Outpatients were referred to "Federico II" University of Naples.
Subjects with a SH without previous/ongoing L-T4 therapy participated in the study.
Changes in major hemostatic/fibrinolytic variables and platelet reactivity [mean platelet volume (MPV), arachidonic acid (AA), or ADP concentrations inducing a ≥ 50% irreversible aggregation (AC-50%)] in SH patients before and after a 6-month L-T4 treatment.
At baseline, 41 SH patients showed higher levels of factor VII activity (123.9 ± 20.4 vs 107.7 ± 12.2, P < .001), plasminogen activator inhibitor-1 (33.6 ± 13.9 vs 22.5 ± 5.74, P < .001) and tissue plasminogen activator (5.56 ± 2.22 vs 4.75 ± 1.61, P = .010), with lower levels of D-dimer (220.3 ± 67.1 vs 252.1 ± 72.4, P = .017) compared with healthy controls. SH patients also showed a higher MPV (9.92 ± 1.15 vs 8.9 ± 0.9, P < .001) and AC-50% to AA (0.18 ± 0.12 vs 0.36 ± 0.10, P < .001) and to ADP (1.5 ± 0.6 vs 1.9 ± 1.3, P = .024). After a 6-month L-T4 therapy, a reduction of factor VII activity (from 123.9 ± 20.4 to 102.6 ± 14.3, P < .001), plasminogen activator inhibitor-1 (33.6 ± 13.9 to 19.4 ± 7.6, P < .001), and tissue plasminogen activator (5.56 ± 2.22 to 1.91 ± 4:43, P = .002) was found in SH subjects, with a marginal increase in D-dimer (from 220.3 ± 67.1 to 245.2 ± 103.1, P = .053). AC-50% to AA (from 0.18 ± 0.12 to 0.54 ± 0.3, P < .001) and to ADP (from 1.5 ± 0.6 to 1.86 ± 0.3, P = .042) were reduced, paralleled by a significant reduction of MPV (from 9.92 ± 1.15 to 9.10 ± 1.23, P = .016).
SH patients exhibit a prothrombotic status, which is reverted by a 6-month L-T4 treatment.
亚临床甲状腺功能减退症（SH）与初级和次级止血的一些异常有关。
本研究旨在评估左甲状腺素（L-T4）治疗对 SH 患者的初级和次级止血的影响。
这是一项具有 6 个月随访的前瞻性队列研究。
那不勒斯“Federico II”大学的门诊患者。
参加研究的 SH 患者无既往/正在进行的 L-T4 治疗。
SH 患者在接受 6 个月 L-T4 治疗前后主要止血/纤维蛋白溶解变量和血小板反应性[平均血小板体积（MPV）、花生四烯酸（AA）或 ADP 浓度诱导≥50%不可逆聚集（AC-50%）]的变化。
在基线时，41 名 SH 患者表现出更高的因子 VII 活性（123.9±20.4 对 107.7±12.2，P<.001）、纤溶酶原激活物抑制剂-1（33.6±13.9 对 22.5±5.74，P<.001）和组织型纤溶酶原激活物（5.56±2.22 对 4.75±1.61，P=0.010），而 D-二聚体水平较低（220.3±67.1 对 252.1±72.4，P=0.017）与健康对照组相比。SH 患者还表现出更高的 MPV（9.92±1.15 对 8.9±0.9，P<.001）和 AA 的 AC-50%（0.18±0.12 对 0.36±0.10，P<.001）和 ADP（1.5±0.6 对 1.9±1.3，P=0.024）。在接受 6 个月 L-T4 治疗后，SH 患者的因子 VII 活性（从 123.9±20.4 降至 102.6±14.3，P<.001）、纤溶酶原激活物抑制剂-1（33.6±13.9 至 19.4±7.6，P<.001）和组织型纤溶酶原激活物（5.56±2.22 至 1.91±4:43，P=0.002）降低，D-二聚体水平略有增加（从 220.3±67.1 至 245.2±103.1，P=0.053）。AA 的 AC-50%（从 0.18±0.12 降至 0.54±0.3，P<.001）和 ADP（从 1.5±0.6 降至 1.86±0.3，P=0.042）降低，同时 MPV 显著降低（从 9.92±1.15 降至 9.10±1.23，P=0.016）。
SH 患者表现出促血栓形成状态，这可通过 6 个月的 L-T4 治疗逆转。
