title: Emerging cardiovascular risk factors in subclinical hypothyroidism: lack of change after restoration of euthyroidism.
abstract: Subclinical hypothyroidism (SH) is a frequent condition that may be associated with increased cardiovascular risk. There is current interest in determining the effect, if any, of substitutive therapy with l-thyroxine (L-T4) on cardiovascular risk factors in SH and, particularly, on those associated with emerging cardiovacular risk, such as apolipoprotein (apo) B, lipoprotein (Lp) (a), total homocysteine (t-Hcy), and C-reactive protein (CRP). Thus, the aim of this study was to assess the impact of euthyroidism restoration on these emerging risk factors in SH. Forty-two patients diagnosed with SH were consecutively recruited before treatment. These patients were treated with L-T4 for 3 to 6 months with the dose necessary to restore euthyroidism. Lp(a), fasting and postmethionine (n = 28) t-Hcy, and CRP did not change with substitutive therapy, regardless of the respective baseline values, and the decrease in apo B paralleled that of low-density lipoprotein (LDL) cholesterol. Similarly, no treatment effect was observed on homocysteine or CRP in patients with thyrotropin-stimulating hormone (TSH) >10 mIU/L. Monitoring of emerging risk factors did not offer additional arguments for treating patients with SH and, thus, is not justified in their clinical management.
authors.affiliation: Serveis d'Endocrinologia, Bioquímica i Institut de Recerca, Hospital Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, 08025 Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Pérez
authors.forename: J M
authors.initials: JM
authors.lastname: Cubero
authors.forename: N
authors.initials: N
authors.lastname: Sucunza
authors.forename: E
authors.initials: E
authors.lastname: Ortega
authors.forename: R
authors.initials: R
authors.lastname: Arcelús
authors.forename: J
authors.initials: J
authors.lastname: Rodriguez-Espinosa
authors.forename: J
authors.initials: J
authors.lastname: Ordoñez-Llanos
authors.forename: F
authors.initials: F
authors.lastname: Blanco-Vaca
mesh_terms: D000328:Adult; D000368:Aged; D001055:Apolipoproteins B / Q000097:blood; D015415:Biomarkers / Q000097:blood*; D002097:C-Reactive Protein / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000097:blood / Q000209:etiology*; D005260:Female; D006710:Homocysteine / Q000097:blood; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000150:complications*; D017270:Lipoprotein(a) / Q000097:blood; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D013973:Thyrotropin-Releasing Hormone / Q000097:blood
chemical_list: D001055:Apolipoproteins B; D015415:Biomarkers; D017270:Lipoprotein(a); D006710:Homocysteine; D013973:Thyrotropin-Releasing Hormone; D002097:C-Reactive Protein