title: Association between serum nitric oxide metabolites and thyroid hormones in a general population: Tehran Thyroid Study.
abstract: Nitric oxide participates in the regulation of thyroid function.
  
  
  OBJECTIVE
  The purpose of this study was to determine whether there is an association between serum nitric oxide metabolites (NOx) and free thyroxine (free T4), anti-thyroid peroxidase (anti-TPO), and thyroid-stimulating hormone (TSH) levels.
  
  
  METHODS
  Study subjects were adults, aged ≥20 years, who participated in the Tehran Thyroid Study (TTS). In a cross-sectional study, in the third phase of TTS, serum NOx concentrations were measured in 1974 adult participants; pregnant women and subjects who had chronic diarrhea, cancer, weight loss, and hospitalization within the past 3 months were excluded, as were those taking medicines that affect thyroid function; the remaining 1771 subjects were grouped according to tertiles of free T4, anti-TPO, and TSH. Spearman's correlation coefficients and multivariable linear regression analysis were used to determine the relationship between serum NOx levels and free T4, anti-TPO, and TSH.
  
  
  RESULTS
  Serum NOx levels were negatively correlated with free T4 in men (r = -0.083; p = 0.029). An inverse association between the third tertile of free T4 and NOx levels was found in both non-adjusted (β = -0.095, p = 0.031) and multivariable-adjusted (β = -0.094, p = 0.039) analyses, only in men. After multivariable adjustment, the third tertile of anti-TPO was significantly associated with NOx levels in women (β = -0.067, p = 0.050).
  
  
  CONCLUSIONS
  Based on the result, serum NOx concentration was found to be associated with free T4 in men and anti-TPO in women.
authors: a Endocrine Physiology Research Center , Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences , Tehran , Iran.|b Endocrine Research Center , Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences , Tehran , Iran.
authors: Fatemeh
authors: F
authors: Bagheripuor
authors: b Endocrine Research Center , Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences , Tehran , Iran.|c Department of Epidemiology and Biostatistics , School of Public Health, Tehran University of Medical Sciences , Tehran , Iran.
authors: Safoora
authors: S
authors: Gharibzadeh
authors: a Endocrine Physiology Research Center , Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences , Tehran , Iran.|b Endocrine Research Center , Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences , Tehran , Iran.
authors: Mahboubeh
authors: M
authors: Ghanbari
authors: b Endocrine Research Center , Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences , Tehran , Iran.
authors: Atieh
authors: A
authors: Amouzegar
authors: d Prevention of Metabolic Disorders Research Center , Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences , Tehran , Iran.
authors: Maryam
authors: M
authors: Tohidi
authors: b Endocrine Research Center , Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences , Tehran , Iran.
authors: Fereidoun
authors: F
authors: Azizi
authors: a Endocrine Physiology Research Center , Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences , Tehran , Iran.|b Endocrine Research Center , Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences , Tehran , Iran.
authors: Asghar
authors: A
authors: Ghasemi
mesh_terms: D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007492:Iran; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000097:blood*; D012737:Sex Factors; D013959:Thyroid Diseases / Q000097:blood* / Q000453:epidemiology; D013963:Thyroid Hormones / Q000097:blood*
chemical_list: D013963:Thyroid Hormones; D009569:Nitric Oxide
keywords: Nitric oxide; population; thyroid hormones