title: Ischemia-modified albumin levels in overt and subclinical hypothyroidism.
abstract: BACKGROUND
  Free radical-mediated oxidative stress (OS) has been implicated in the pathogenesis of thyroid disorders. The ischemia-modified albumin (IMA) has been proposed as a marker of protein oxidative damage, which has been found to reflect hypoxic stress.
  
  
  OBJECTIVE
  Our aim was to evaluate IMA, malondialdehyde (MDA), and reduced glutathione (GSH) levels in patients with overt hypothyroidism (OHT) and subclinical hypothyroidism (SHT) in comparison to euthyroid controls.
  
  
  METHODS
  Albumin, IMA, IMA/albumin ratio, MDA, GSH, total cholesterol (TC), triglycerides (TG), HDL-Cholesterol were assessed in 105 subjects grouped into OHT, SHT patients, and euthyroid controls with 35 subjects in each group.
  
  
  RESULTS
  MDA and IMA levels were significantly elevated while the GSH concentrations were significantly lower in OHT and SHT patients compared to controls (p < 0.01). When IMA values were normalized for albumin concentrations, the IMA/albumin ratio was also significantly elevated in both patient groups compared to controls (p < 0.01). These changes were more pronounced in the OHT group when compared to SHT group. In OHT group, thyroid-stimulating hormone (TSH) levels showed significant positive correlation with MDA (r = 0.470, p = 0.004), IMA (r = 0.530, p = 0.001), and IMA/albumin ratio (r = 0.525, p = 0.001). Both IMA (r = -0.342, p = 0.041), IMA/albumin ratio (r = -0.378, p = 0.023) showed significant negative correlation with GSH in OHT patients. No significant correlation between variables was, however, observed in SHT group.
  
  
  CONCLUSIONS
  Increase of MDA and IMA levels with decreased antioxidant status indicate the presence of OS in hypothyroid patients, which was more pronounced in OHT patients. Elevated levels of IMA can be a clinically useful marker of protein oxidative damage and OS in hypothyroidism.
authors: Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, India.
authors: S V
authors: SV
authors: Reddy
authors: M M
authors: MM
authors: Suchitra
authors: V
authors: V
authors: Pradeep
authors: S
authors: S
authors: Alok
authors: V
authors: V
authors: Suresh
authors: A R
authors: AR
authors: Bitla
authors: P V L N
authors: PV
authors: Srinivasa Rao
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood* / Q000175:diagnosis*; D008297:Male; D018384:Oxidative Stress / Q000502:physiology; D012709:Serum Albumin; D000075462:Serum Albumin, Human
chemical_list: D015415:Biomarkers; D012709:Serum Albumin; C561522:ischemia-modified albumin; D000075462:Serum Albumin, Human