title: Low free-thyroxine levels are a risk factor for subclinical atherosclerosis in euthyroid hyperlipidemic patients.
abstract: BACKGROUND
  Patients displaying overt and subclinical hypothyroidism have more cardiovascular risk factors. Consequently, they are more likely to develop atherosclerosis and cardiovascular diseases.
  
  
  OBJECTIVE
  To analyze whether low free-thyroxine levels (FTL) would also be associated with atherosclerosis in euthyroid patients.
  
  
  METHODS
  We selected a group of 1434 healthy euthyroid male patients without known histories of thyroid disease and with levels of thyroid-stimulating hormone values within the normal range (mean 1.70+/-0.76 mUl/l, range 0.13-4.01 mUl/l). Mean age of these patients who had been referred for assessment of hyperlipidemia was 44.6 years and mean FTL was 14.25+/-3.06 pmol/l. We divided the population according to the degree of atherosclerosis in the carotid arteries.
  
  
  RESULTS
  Mean age, body mass index, systolic blood pressure, cigarettes/day, blood level of glucose, cholesterol levels, and fibrinogen levels were significantly higher for the patients with atherosclerotic lesions whereas mean FTL was lower for patients with carotid atherosclerosis (P = 0.0002). The relationship between FTL and carotid atherosclerosis was independent from the following cardiovascular risk factors: age, hypertension, amount of excess weight, cholesterol level, fibrinogen level, smoking status, and presence versus absence of diabetes mellitus.
  
  
  CONCLUSIONS
  Low FTL is a risk factor for atherosclerosis in male euthyroid hyperlipidemic patients.
authors.affiliation: Service d'Endocrinologie-Métabolisme, Hôpital Pitié Salpétrière, Paris, France. eric.bruckert@psl.ap-hop-paris.fr
authors.forename: E
authors.initials: E
authors.lastname: Bruckert
authors.forename: P
authors.initials: P
authors.lastname: Giral
authors.forename: R
authors.initials: R
authors.lastname: Chadarevian
authors.forename: G
authors.initials: G
authors.lastname: Turpin
mesh_terms: D000328:Adult; D000368:Aged; D001161:Arteriosclerosis / Q000097:blood* / Q000000981:diagnostic imaging; D016893:Carotid Stenosis / Q000097:blood* / Q000000981:diagnostic imaging; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D013974:Thyroxine / Q000097:blood*; D014463:Ultrasonography
chemical_list: D013974:Thyroxine