title: The Association of Subclinical Hypothyroidism and Pattern of Circulating Endothelial-Derived Microparticles Among Chronic Heart Failure Patients.
abstract: BACKGROUND
  Subclinical hypothyroidism (SH) is diagnosed biochemically by the presence of normal serum free thyroxine concentration, in conjunction with an elevated serum thyroid-stimulating hormone level. Recent studies have demonstrated the frequent association between SH and cardiovascular diseases and risk factors.
  
  
  OBJECTIVE
  To evaluate the impact of SH on patterns of circulating endothelial-derived microparticles, (EMPs) among chronic heart failure (CHF) patients.
  
  
  METHODS
  This is a retrospective study involving a cohort of 388 patients with CHF. Fifty-three CHF subjects had SH and 335 patients were free from thyroid dysfunction. Circulating levels of N-terminal-pro brain natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein (hs-CRP), thyroid-stimulating hormone (TSH), total and free thyroxine (T4), and triiodothyronine (T3), and endothelial apoptotic microparticles (EMPs), were measured at baseline. SH was defined, according to contemporary clinical guidelines, as a biochemical state associated with an elevated serum TSH level of greater 10 μU/L and normal basal free T3 and T4 concentrations.
  
  
  RESULTS
  Circulating CD31+/annexin V+ EMPs were higher in patients with SH compared to those without SH. In contrast, activated CD62E+ EMP numbers were not significantly different between both patient cohorts. Using uni (bi) variate and multivariate age- and gender-adjusted regression analysis, we found several predictors that affected the increase of the CD31+/annexin V+ to CD62E+ ratio in the patient study population. The independent impact of TSH per 6.5 μU/L (odds ratio [OR] = 1.23, P = 0.001), SH (OR = 1.22, P = 0.001), NT-proBNP (OR = 1.19, P = 0.001), NYHA class (OR = 1.09, P = 0.001), hs-CRP per 4.50 mg/L (OR = 1.05, P = 0.001), dyslipidemia (OR = 1.06, P = 0.001), serum uric acid per 9.5 mmol/L (OR = 1.04, P = 0.022) on the increase in the CD31+/annexin V+ to CD62E+ ratio, was determined.
  
  
  CONCLUSIONS
  We believe that the SH state in CHF patients may be associated with the impaired pattern of circulating EMPs, with the predominantly increased number of apoptotic-derived microparticles.
authors.affiliation: Consultant of Therapeutic Unit, Internal Medicine Department, State Medical University, Zaporozhye, Ukraine.
authors.forename: Alexander E
authors.initials: AE
authors.lastname: Berezin
authors.affiliation: Clinical Pharmacology Department, State Medical University, Zaporozhye, Ukraine.
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Kremzer
authors.affiliation: Cytofloumetry Department, Zaporozhye, Ukraine.
authors.forename: Yulia V
authors.initials: YV
authors.lastname: Martovitskaya
authors.affiliation: Clinical Pharmacology Department, State Medical University, Zaporozhye, Ukraine.
authors.forename: Tatyana A
authors.initials: TA
authors.lastname: Samura
authors.affiliation: Private Medical Center Vita-Center, Zaporozhye, Ukraine.
authors.forename: Tatyana A
authors.initials: TA
authors.lastname: Berezina
keywords: Chronic Heart Failure; Microparticles; Thyroid Dysfunction