title: Primary and Secondary Hemostasis in Patients With Subclinical Hypothyroidism: Effect of Levothyroxine Treatment.
abstract: BACKGROUND
  Subclinical hypothyroidism (SH) is associated with some abnormalities in primary and secondary hemostasis.
  
  
  OBJECTIVE
  The objective of the study was to evaluate changes in primary and secondary hemostasis induced by levothyroxine (L-T4) treatment in SH patients.
  
  
  METHODS
  This was a prospective cohort study with a 6-month follow-up.
  
  
  METHODS
  Outpatients were referred to "Federico II" University of Naples.
  
  
  METHODS
  Subjects with a SH without previous/ongoing L-T4 therapy participated in the study.
  
  
  METHODS
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  SH patients exhibit a prothrombotic status, which is reverted by a 6-month L-T4 treatment.
authors.affiliation: 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.
authors.forename: Roberta
authors.initials: R
authors.lastname: Lupoli
authors.affiliation: 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.
authors.forename: Matteo Nicola Dario
authors.initials: MN
authors.lastname: Di Minno
authors.affiliation: 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.
authors.forename: Anna
authors.initials: A
authors.lastname: Tortora
authors.affiliation: 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.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Scaravilli
authors.affiliation: 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.
authors.forename: Marianna
authors.initials: M
authors.lastname: Cacciapuoti
authors.affiliation: 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.
authors.forename: Livia
authors.initials: L
authors.lastname: Barba
authors.affiliation: 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.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Di Minno
authors.affiliation: 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.
authors.forename: Pasquale
authors.initials: P
authors.lastname: Ambrosino
authors.affiliation: 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.
authors.forename: Gelsy Arianna
authors.initials: GA
authors.lastname: Lupoli
authors.affiliation: 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.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Lupoli
mesh_terms: D000328:Adult; D058070:Asymptomatic Diseases; D005260:Female; D005342:Fibrinolysis / Q000187:drug effects; D005500:Follow-Up Studies; D006487:Hemostasis / Q000187:drug effects*; D006801:Humans; D007037:Hypothyroidism / Q000097:blood* / Q000150:complications / Q000188:drug therapy*; D008297:Male; D063847:Mean Platelet Volume; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects; D013974:Thyroxine / Q000494:pharmacology* / Q000627:therapeutic use*
chemical_list: D013974:Thyroxine