title: Association of thyroid dysfunction with vitamin B12, folate and plasma homocysteine levels in the elderly: a population-based study in Sicily.
abstract: BACKGROUND
  Association of thyroid dysfunction with plasma homocysteine levels and vitamin B(12) has previously been reported. We evaluated these associations in the elderly in San Teodoro, a mountainous village of Sicily.
  
  
  METHODS
  Subjects (n=279) aged 60-85 years (119 males and 160 females) were examined using self-reported signs, clinical examination and laboratory tests.
  
  
  RESULTS
  Hypothyroidism and/or goiter were two characteristics that were not associated with a significant change in homocysteine when compared with euthyroidism and the absence of goiter. Vitamin B(12) was significantly higher in subjects in the first quartile of the thyroid-stimulating hormone distribution, compared with those in the fourth quartile (371+/-207 vs. 297+/-196 pmol/L, p=0.0121). Homocysteine was significantly higher in the first quartile of the free tri-iodothyronine distribution compared to the third quartile (18.0+/-5.7 vs. 16.0+/-6.2 micromol/L, p=0.0130) and was correlated with log tri-iodothyronine in euthyroid subjects (p=0.0254). In multivariate analysis, homocysteine was associated with vitamin B(12) (p=0.0014), folate (p<0.0001), creatinine (p<0.0001) and age (p<0.0001), but not with either free tri-iodothyronine (p=0.7680), tetra-iodothyronine (p=0.5706) or thyroid-stimulating hormone (p=0.2294).
  
  
  CONCLUSIONS
  Our results suggest that the influence of thyroid hormones on homocysteine is much weaker in elderly subjects than in selected patients with hypothyroidism.
authors.affiliation: Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Troina (EN), Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Stella
authors.forename: Rosario Sebastiano
authors.initials: RS
authors.lastname: Spada
authors.forename: Santa
authors.initials: S
authors.lastname: Calabrese
authors.forename: Paolo
authors.initials: P
authors.lastname: Bosco
authors.forename: Guido
authors.initials: G
authors.lastname: Anello
authors.forename: Rosa-Maria
authors.initials: RM
authors.lastname: Guéant-Rodriguez
authors.forename: Antonino
authors.initials: A
authors.lastname: Romano
authors.forename: Lahoucine
authors.initials: L
authors.lastname: Benamghar
authors.forename: Caterina
authors.initials: C
authors.lastname: Proto
authors.forename: Antonino
authors.initials: A
authors.lastname: Castellano
authors.forename: Adrian
authors.initials: A
authors.lastname: Fajardo
authors.forename: Lina
authors.initials: L
authors.lastname: Lipari
authors.forename: Salvatore
authors.initials: S
authors.lastname: Sirna
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Guéant
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood / Q000473:pathology*; D004813:Epidemiology; D005260:Female; D005492:Folic Acid / Q000097:blood*; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012802:Sicily / Q000453:epidemiology; D013959:Thyroid Diseases / Q000097:blood / Q000453:epidemiology*; D014805:Vitamin B 12 / Q000097:blood*
chemical_list: D006710:Homocysteine; D005492:Folic Acid; D014805:Vitamin B 12